#include "parser.h"

#ifdef DEBUG
static unsigned int shiftwidth = 0;
void shiftout(void) { shiftwidth += 4; }
void shiftin(void) { shiftwidth -= 4; }
void debug(const char *info)
{
	int n;
	for (n = 0; n < shiftwidth; n++)
		fprintf(stderr, " ");
	fprintf(stderr, "%s\n", info);
}
#endif

/**
 * Creates the main code block of a program.
 *
 * \param [in] block The first code block to execute.
 *
 * \return A pointer to the main code block with the desired properties.
 *
 * \retval NULL Memory allocation failed.
 */
MainNode *createMainNode(BlockNode *block)
{
	MainNode *p = malloc(sizeof(MainNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->block = block;
	return p;
}

/**
 * Deletes the main code block of a program.
 *
 * \param [in,out] node The main code block to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteMainNode(MainNode *node)
{
	if (!node) return;
	deleteBlockNode(node->block);
	free(node);
}

/**
 * Creates a code block.
 *
 * \param [in] stmts The list of statements which comprise the code block.
 *
 * \return A pointer to the code block with the desired properties.
 *
 * \retval NULL Memory allocation failed.
 */
BlockNode *createBlockNode(StmtNodeList *stmts)
{
	BlockNode *p = malloc(sizeof(BlockNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->stmts = stmts;
	return p;
}

/**
 * Deletes a code block.
 *
 * \param [in,out] node The code block to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteBlockNode(BlockNode *node)
{
	if (!node) return;
	deleteStmtNodeList(node->stmts);
	free(node);
}

/**
 * Creates an empty code block list.
 *
 * \return A pointer to an empty code block list.
 *
 * \retval NULL Memory allocation failed.
 */
BlockNodeList *createBlockNodeList(void)
{
	BlockNodeList *p = malloc(sizeof(BlockNodeList));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->num = 0;
	p->blocks = NULL;
	return p;
}

/**
 * Adds a code block to a list.
 *
 * \param [in,out] list The code block list to add \a node to.
 *
 * \param [in] node The code block to add to \a list.
 *
 * \post \a node will be added to \a list and its size will be updated.
 *
 * \retval 0 Memory allocation failed.
 *
 * \retval 1 \a node was added to \a list.
 */
int addBlockNode(BlockNodeList *list,
                 BlockNode *node)
{
	unsigned int newsize = list->num + 1;
	void *mem = realloc(list->blocks, sizeof(BlockNode *) * newsize);
	if (!mem) {
		perror("realloc");
		return 0;
	}
	list->blocks = mem;
	list->blocks[list->num] = node;
	list->num = newsize;
	return 1;
}

/**
 * Deletes a code block list.
 *
 * \param [in,out] list The code block list to delete.
 *
 * \post The memory at \a list and all of its members will be freed.
 */
void deleteBlockNodeList(BlockNodeList *list)
{
	unsigned int n;
	if (!list) return;
	for (n = 0; n < list->num; n++)
		deleteBlockNode(list->blocks[n]);
	free(list->blocks);
	free(list);
}

/**
 * Creates a boolean constant.
 *
 * \param [in] data The boolean constant value.
 *
 * \return A pointer to a boolean constant which will be FALSE if \a data is \c
 * 0 and TRUE otherwise.
 *
 * \retval NULL Memory allocation failed.
 */
ConstantNode *createBooleanConstantNode(int data)
{
	ConstantNode *p = malloc(sizeof(ConstantNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->type = CT_BOOLEAN;
	p->data.i = (data != 0);
	return p;
}

/**
 * Creates an integer constant.
 *
 * \param [in] data The integer constant value.
 *
 * \return A pointer to an integer constant whose value is \a data.
 *
 * \retval NULL Memory allocation failed.
 */
ConstantNode *createIntegerConstantNode(long long data)
{
	ConstantNode *p = malloc(sizeof(ConstantNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->type = CT_INTEGER;
	p->data.i = data;
	return p;
}

/**
 * Creates a float constant.
 *
 * \param [in] data The float constant value.
 *
 * \return A pointer to a float constant whose value is \a data.
 *
 * \retval NULL Memory allocation failed.
 */
ConstantNode *createFloatConstantNode(float data)
{
	ConstantNode *p = malloc(sizeof(ConstantNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->type = CT_FLOAT;
	p->data.f = data;
	return p;
}

/**
 * Creates a string constant.
 *
 * \param [in] data The string constant value.
 *
 * \return A pointer to the string constant whose value is \a data.
 *
 * \retval NULL Memory allocation failed.
 */
ConstantNode *createStringConstantNode(char *data)
{
	ConstantNode *p = malloc(sizeof(ConstantNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->type = CT_STRING;
	p->data.s = data;
	return p;
}

/**
 * Deletes a constant.
 *
 * \param [in,out] node The constant to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteConstantNode(ConstantNode *node)
{
	if (!node) return;
	if (node->type == CT_STRING) free(node->data.s);
	free(node);
}

/**
 * Creates an indentifier.
 *
 * \param [in] type The type of the identifier \a id.
 *
 * \param [in] id The identifier data.
 *
 * \param [in] slot An optional slot to index.
 *
 * \param [in] fname The file containing the identifier.
 *
 * \param [in] line The line the identifier occurred on.
 *
 * \return A pointer to the identifier with the desired properties.
 *
 * \retval NULL Memory allocation failed.
 */
IdentifierNode *createIdentifierNode(IdentifierType type,
                                     void *id,
                                     IdentifierNode *slot,
                                     const char *fname,
                                     unsigned int line)
{
	IdentifierNode *p = malloc(sizeof(IdentifierNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->type = type;
	p->id = id;
	p->slot = slot;
	if (fname) {
		p->fname = malloc(sizeof(char) * (strlen(fname) + 1));
		strcpy(p->fname, fname);
	}
	else {
		p->fname = NULL;
	}
	p->line = line;
	return p;
}

/**
 * Deletes an identifier.
 *
 * \param [in,out] node The identifier to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteIdentifierNode(IdentifierNode *node)
{
	if (!node) return;
	switch (node->type) {
		case IT_DIRECT: {
			free(node->id);
			break;
		}
		case IT_INDIRECT: {
			deleteExprNode(node->id);
			break;
		}
		default:
			error(PR_UNKNOWN_IDENTIFIER_TYPE, node->fname, node->line);
			break;
	}
	if (node->slot) deleteIdentifierNode(node->slot);
	if (node->fname) free(node->fname);
	free(node);
}

/**
 * Creates an identifier list.
 *
 * \return A pointer to an identifier list.
 *
 * \retval NULL Memory allocation failed.
 */
IdentifierNodeList *createIdentifierNodeList(void)
{
	IdentifierNodeList *p = malloc(sizeof(IdentifierNodeList));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->num = 0;
	p->ids = NULL;
	return p;
}

/**
 * Adds an identifier to a list.
 *
 * \param [in,out] list The list of identifiers to add \a node to.
 *
 * \param [in] node The identifier to add to \a list.
 *
 * \post \a token will be added to the end of \a list and the size of \a list
 * will be updated.
 *
 * \retval 0 Memory allocation failed.
 *
 * \retval 1 \a node was added to \a list.
 */
int addIdentifierNode(IdentifierNodeList *list,
                      IdentifierNode *node)
{
	unsigned int newsize = list->num + 1;
	void *mem = realloc(list->ids, sizeof(IdentifierNode *) * newsize);
	if (!mem) {
		perror("realloc");
		return 0;
	}
	list->ids = mem;
	list->ids[list->num] = node;
	list->num = newsize;
	return 1;
}

/**
 * Deletes an identifier list.
 *
 * \param [in,out] list The list of identifiers to delete.
 *
 * \post The memory at \a list and all of its members will be freed.
 */
void deleteIdentifierNodeList(IdentifierNodeList *list)
{
	unsigned int n;
	if (!list) return;
	for (n = 0; n < list->num; n++)
		deleteIdentifierNode(list->ids[n]);
	free(list->ids);
	free(list);
}

/**
 * Creates a type.
 *
 * \param [in] type The type to create.
 *
 * \return A pointer to a new type with the desired properties.
 *
 * \retval NULL Memory allocatin failed.
 */
TypeNode *createTypeNode(ConstantType type)
{
	TypeNode *p = malloc(sizeof(TypeNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->type = type;
	return p;
}

/**
 * Deletes a type.
 *
 * \param [in,out] node The type to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteTypeNode(TypeNode *node)
{
	if (!node) return;
	free(node);
}

/**
 * Creates a statement.
 *
 * \param [in] type The type of statement.
 *
 * \param [in] stmt The statement data.
 *
 * \return A pointer to a statement with the desired properties.
 *
 * \retval NULL malloc was unable to allocate memory.
 */
StmtNode *createStmtNode(StmtType type,
                         void *stmt)
{
	StmtNode *p = malloc(sizeof(StmtNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->type = type;
	p->stmt = stmt;
	return p;
}

/**
 * Deletes a statement.
 *
 * \param [in,out] node The statement to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteStmtNode(StmtNode *node)
{
	if (!node) return;
	switch (node->type) {
		case ST_CAST: {
			CastStmtNode *stmt = (CastStmtNode *)node->stmt;
			deleteCastStmtNode(stmt);
			break;
		}
		case ST_PRINT: {
			PrintStmtNode *stmt = (PrintStmtNode *)node->stmt;
			deletePrintStmtNode(stmt);
			break;
		}
		case ST_INPUT: {
			InputStmtNode *stmt = (InputStmtNode *)node->stmt;
			deleteInputStmtNode(stmt);
			break;
		}
		case ST_ASSIGNMENT: {
			AssignmentStmtNode *stmt = (AssignmentStmtNode *)node->stmt;
			deleteAssignmentStmtNode(stmt);
			break;
		}
		case ST_DECLARATION: {
			DeclarationStmtNode *stmt = (DeclarationStmtNode *)node->stmt;
			deleteDeclarationStmtNode(stmt);
			break;
		}
		case ST_IFTHENELSE: {
			IfThenElseStmtNode *stmt = (IfThenElseStmtNode *)node->stmt;
			deleteIfThenElseStmtNode(stmt);
			break;
		}
		case ST_SWITCH: {
			SwitchStmtNode *stmt = (SwitchStmtNode *)node->stmt;
			deleteSwitchStmtNode(stmt);
			break;
		}
		case ST_BREAK:
			break; /* This statement type does not have any content */
		case ST_RETURN: {
			ReturnStmtNode *stmt = (ReturnStmtNode *)node->stmt;
			deleteReturnStmtNode(stmt);
			break;
		}
		case ST_LOOP: {
			LoopStmtNode *stmt = (LoopStmtNode *)node->stmt;
			deleteLoopStmtNode(stmt);
			break;
		}
		case ST_DEALLOCATION: {
			DeallocationStmtNode *stmt = (DeallocationStmtNode *)node->stmt;
			deleteDeallocationStmtNode(stmt);
			break;
		}
		case ST_FUNCDEF: {
			FuncDefStmtNode *stmt = (FuncDefStmtNode *)node->stmt;
			deleteFuncDefStmtNode(stmt);
			break;
		}
		case ST_EXPR: {
			ExprNode *expr = (ExprNode *)node->stmt;
			deleteExprNode(expr);
			break;
		}
		case ST_ALTARRAYDEF: {
			AltArrayDefStmtNode *stmt = (AltArrayDefStmtNode *)node->stmt;
			deleteAltArrayDefStmtNode(stmt);
			break;
		}
		case ST_BINDING: {
			BindingStmtNode *stmt = (BindingStmtNode *)node->stmt;
			deleteBindingStmtNode(stmt);
			break;
		}
		case ST_IMPORT: {
			ImportStmtNode *stmt = (ImportStmtNode *)node->stmt;
			deleteImportStmtNode(stmt);
			break;
		}
		default:
			error(PR_UNKNOWN_STATEMENT_TYPE);
			break;
	}
	free(node);
}

/**
 * Creates an empty statement list.
 *
 * \return A pointer to an empty statement list.
 *
 * \retval NULL Memory allocation failed.
 */
StmtNodeList *createStmtNodeList(void)
{
	StmtNodeList *p = malloc(sizeof(StmtNodeList));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->num = 0;
	p->stmts = NULL;
	return p;
}

/**
 * Adds a statement to a list.
 *
 * \param [in,out] list The statement list to add \a node to.
 *
 * \param [in] node The statement to add to \a list.
 *
 * \post \a node will be added to \a list and its size will be updated.
 *
 * \retval 0 Memory allocation failed.
 *
 * \retval 1 \a node was added to \a list.
 */
int addStmtNode(StmtNodeList *list,
                StmtNode *node)
{
	unsigned int newsize = list->num + 1;
	void *mem = realloc(list->stmts, sizeof(StmtNode *) * newsize);
	if (!mem) {
		perror("realloc");
		return 0;
	}
	list->stmts = mem;
	list->stmts[list->num] = node;
	list->num = newsize;
	return 1;
}

/**
 * Deletes a statement list.
 *
 * \param [in,out] list The statement list to delete.
 *
 * \post The memory at \a list and all of its members will be freed.
 */
void deleteStmtNodeList(StmtNodeList *list)
{
	unsigned int n;
	if (!list) return;
	for (n = 0; n < list->num; n++)
		deleteStmtNode(list->stmts[n]);
	free(list->stmts);
	free(list);
}

/**
 * Creates a cast statement.
 *
 * \param [in] target The variable to cast to \a newtype.
 *
 * \param [in] newtype The type to cast \a target to.
 *
 * \return A pointer to a cast statement with the desired properties.
 *
 * \retval NULL Memory allocation failed.
 */
CastStmtNode *createCastStmtNode(IdentifierNode *target,
                                 TypeNode *newtype)
{
	CastStmtNode *p = malloc(sizeof(CastStmtNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->target = target;
	p->newtype = newtype;
	return p;
}

/**
 * Deletes a cast statement.
 *
 * \param [in,out] node The cast statement to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteCastStmtNode(CastStmtNode *node)
{
	if (!node) return;
	deleteIdentifierNode(node->target);
	deleteTypeNode(node->newtype);
	free(node);
}

/**
 * Creates a print statement.
 *
 * \param [in] args The expressions to print.
 *
 * \param [in] nonl Whether an ending newline should be surpressed.
 *
 * \return A pointer to the print statement with the desired properties.
 *
 * \retval NULL Memory allocation failed.
 */
PrintStmtNode *createPrintStmtNode(ExprNodeList *args,
                                   int nonl)
{
	PrintStmtNode *p = malloc(sizeof(PrintStmtNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->args = args;
	p->nonl = nonl;
	return p;
}

/**
 * Deletes a print statement.
 *
 * \param [in,out] node The print statement to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deletePrintStmtNode(PrintStmtNode *node)
{
	if (!node) return;
	deleteExprNodeList(node->args);
	free(node);
}

/**
 * Creates an input statement.
 *
 * \param [in] target The variable to store input in.
 *
 * \return A pointer to an input statement with the desired properties.
 *
 * \retval NULL Memory allocation failed.
 */
InputStmtNode *createInputStmtNode(IdentifierNode *target)
{
	InputStmtNode *p = malloc(sizeof(InputStmtNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->target = target;
	return p;
}

/**
 * Deletes an input statement.
 *
 * \param [in,out] node The input statement to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteInputStmtNode(InputStmtNode *node)
{
	if (!node) return;
	deleteIdentifierNode(node->target);
	free(node);
}

/**
 * Creates an assignment statement.
 *
 * \param [in] target The variable to store \a expr in.
 *
 * \param [in] expr The expression to store in \a target.
 *
 * \return A pointer to an assignment statement with the desired properties.
 *
 * \retval NULL Memory allocation failed.
 */
AssignmentStmtNode *createAssignmentStmtNode(IdentifierNode *target,
                                             ExprNode *expr)
{
	AssignmentStmtNode *p = malloc(sizeof(AssignmentStmtNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->target = target;
	p->expr = expr;
	return p;
}

/**
 * Deletes an assignment statement.
 *
 * \param [in,out] node The assignment statement to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteAssignmentStmtNode(AssignmentStmtNode *node)
{
	if (!node) return;
	deleteIdentifierNode(node->target);
	deleteExprNode(node->expr);
	free(node);
}

/**
 * Creates a declaration statement.
 *
 * \param [in] scope The scope to create the variable in.
 *
 * \param [in] target The variable to create.
 *
 * \param [in] expr An optional expression to initialize \a target to.
 *
 * \param [in] type An optional type to initialize \a target to.
 *
 * \param [in] parent The optional parent to inherit from.
 *
 * \return A pointer to a declaration statement with the desired properties.
 *
 * \retval NULL Memory allocation failed.
 */
DeclarationStmtNode *createDeclarationStmtNode(IdentifierNode *scope,
                                               IdentifierNode *target,
                                               ExprNode *expr,
                                               TypeNode *type,
                                               IdentifierNode *parent)
{
	DeclarationStmtNode *p = malloc(sizeof(DeclarationStmtNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->scope = scope;
	p->target = target;
	p->expr = expr;
	p->type = type;
	p->parent = parent;
	return p;
}

/**
 * Deletes a declaration statement.
 *
 * \param [in,out] node The declaration statement to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteDeclarationStmtNode(DeclarationStmtNode *node)
{
	if (!node) return;
	deleteIdentifierNode(node->scope);
	deleteIdentifierNode(node->target);
	deleteExprNode(node->expr);
	deleteTypeNode(node->type);
	deleteIdentifierNode(node->parent);
	free(node);
}

/**
 * Creates an if/then/else statement.
 *
 * \param [in] yes The code block to execute if the \ref impvar "implicit
 * variable" is \c true.
 *
 * \param [in] no The code block to execute if the \ref impvar "implicit
 * variable" is \c false and all \a guards are \c false.
 *
 * \param [in] guards The expressions to test if the \ref impvar "implicit
 * variable" is \c false.
 *
 * \param [in] blocks The code blocks to execute if the respective guard is \c
 * true.
 *
 * \return A pointer to the if/then/else statement with the desired properties.
 *
 * \retval NULL Memory allocation failed.
 */
IfThenElseStmtNode *createIfThenElseStmtNode(BlockNode *yes,
                                             BlockNode *no,
                                             ExprNodeList *guards,
                                             BlockNodeList *blocks)
{
	IfThenElseStmtNode *p = malloc(sizeof(IfThenElseStmtNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->yes = yes;
	p->no = no;
	p->guards = guards;
	p->blocks = blocks;
	return p;
}

/**
 * Deletes an if/then/else statement.
 *
 * \param [in,out] node The if/then/else statement to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteIfThenElseStmtNode(IfThenElseStmtNode *node)
{
	if (!node) return;
	deleteBlockNode(node->yes);
	deleteBlockNode(node->no);
	deleteExprNodeList(node->guards);
	deleteBlockNodeList(node->blocks);
	free(node);
}

/**
 * Creates a switch statement.
 *
 * \param [in] guards The expressions to compare the the \ref impvar "implicit
 * variable".
 *
 * \param [in] blocks The code blocks to execute if a respective guard matches
 * the \ref impvar "implicit variable".
 *
 * \param [in] def The default code block to execute if none of the \a guards
 * match the \ref impvar "implicit variable".
 *
 * \return A pointer to a switch statement with the desired properties.
 *
 * \retval NULL Memory allocation failed.
 */
SwitchStmtNode *createSwitchStmtNode(ExprNodeList *guards,
                                     BlockNodeList *blocks,
                                     BlockNode *def)
{
	SwitchStmtNode *p = malloc(sizeof(SwitchStmtNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->guards = guards;
	p->blocks = blocks;
	p->def = def;
	return p;
}

/**
 * Deletes a switch statement.
 *
 * \param [in,out] node The switch statement to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteSwitchStmtNode(SwitchStmtNode *node)
{
	if (!node) return;
	deleteExprNodeList(node->guards);
	deleteBlockNodeList(node->blocks);
	deleteBlockNode(node->def);
	free(node);
}

/**
 * Creates a return statement.
 *
 * \param [in] value The return value.
 *
 * \return A pointer to a return statement of the desired properties.
 *
 * \retval NULL Memory allocation failed.
 */
ReturnStmtNode *createReturnStmtNode(ExprNode *value)
{
	ReturnStmtNode *p = malloc(sizeof(ReturnStmtNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->value = value;
	return p;
}

/**
 * Deletes a return statement.
 *
 * \param [in,out] node The return statement to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteReturnStmtNode(ReturnStmtNode *node)
{
	if (!node) return;
	deleteExprNode(node->value);
	free(node);
}

/**
 * Creates a loop statement.
 *
 * \param [in] name The name of the loop.
 *
 * \param [in] var The induction variable.
 *
 * \param [in] guard The expression to determine if the loop continues.
 *
 * \param [in] update The expression to update \a var using.
 *
 * \param [in] body The code block to execute with each loop iteration.
 *
 * \return A pointer to a loop statement with the desired properties.
 *
 * \retval NULL Memory allocation failed.
 */
LoopStmtNode *createLoopStmtNode(IdentifierNode *name,
                                 IdentifierNode *var,
                                 ExprNode *guard,
                                 ExprNode *update,
                                 BlockNode *body)
{
	LoopStmtNode *p = malloc(sizeof(LoopStmtNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->name = name;
	p->var = var;
	p->guard = guard;
	p->update = update;
	p->body = body;
	return p;
}

/**
 * Deletes a loop statement.
 *
 * \param [in,out] node The loop statement to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteLoopStmtNode(LoopStmtNode *node)
{
	if (!node) return;
	deleteIdentifierNode(node->name);
	deleteIdentifierNode(node->var);
	deleteExprNode(node->guard);
	deleteExprNode(node->update);
	deleteBlockNode(node->body);
	free(node);
}

/**
 * Creates a deallocation statement.
 *
 * \param [in] target The variable to deallocate.
 *
 * \return A pointer to a deallocation statement with the desired properties.
 *
 * \retval NULL Memory allocation failed.
 */
DeallocationStmtNode *createDeallocationStmtNode(IdentifierNode *target)
{
	DeallocationStmtNode *p = malloc(sizeof(DeallocationStmtNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->target = target;
	return p;
}

/**
 * Deletes a deallocation statement.
 *
 * \param [in,out] node The deallocation statement to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteDeallocationStmtNode(DeallocationStmtNode *node)
{
	if (!node) return;
	deleteIdentifierNode(node->target);
	free(node);
}

/**
 * Creates a function definition statement.
 *
 * \param [in] scope The scope to define the function in.
 *
 * \param [in] name The name of the function.
 *
 * \param [in] args The function arguments names.
 *
 * \param [in] body The function's code block.
 *
 * \return A pointer to a function definition statement with the desired
 * properties.
 *
 * \retval NULL Memory allocation failed.
 */
FuncDefStmtNode *createFuncDefStmtNode(IdentifierNode *scope,
                                       IdentifierNode *name,
                                       IdentifierNodeList *args,
                                       BlockNode *body)
{
	FuncDefStmtNode *p = malloc(sizeof(FuncDefStmtNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->scope = scope;
	p->name = name;
	p->args = args;
	p->body = body;
	return p;
}

/**
 * Deletes a function definition statement.
 *
 * \param [in,out] node The function definition statement to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteFuncDefStmtNode(FuncDefStmtNode *node)
{
	if (!node) return;
	deleteIdentifierNode(node->scope);
	deleteIdentifierNode(node->name);
	deleteIdentifierNodeList(node->args);
	deleteBlockNode(node->body);
	free(node);
}

/**
 * Creates an alternate array definition statement.
 *
 * \param [in] name The name of the array to define.
 *
 * \param [in] body The body of the array to define.
 *
 * \param [in] parent The optional parent to inherit from.
 *
 * \return A pointer to an array definition statement with the desired
 * properties.
 *
 * \retval NULL Memory allocation failed.
 */
AltArrayDefStmtNode *createAltArrayDefStmtNode(IdentifierNode *name,
                                               BlockNode *body,
                                               IdentifierNode *parent)
{
	AltArrayDefStmtNode *p = malloc(sizeof(AltArrayDefStmtNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->name = name;
	p->body = body;
	p->parent = parent;
	return p;
}

/**
 * Deletes an alternate array definition statement.
 *
 * \param [in,out] node The alternate array definition statement to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteAltArrayDefStmtNode(AltArrayDefStmtNode *node)
{
	if (!node) return;
	deleteIdentifierNode(node->name);
	deleteBlockNode(node->body);
	free(node);
}

/**
 * Creates a library import statement.
 *
 * \param [in] name The name of the library to import.
 *
 * \return A pointer to a library import statement with the desired properties.
 *
 * \retval NULL Memory allocation failed.
 */
ImportStmtNode *createImportStmtNode(IdentifierNode *name)
{
	ImportStmtNode *p = malloc(sizeof(ImportStmtNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->name = name;
	return p;
}

/**
 * Deletes a library import statement.
 *
 * \param [in,out] node The library import statement to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteImportStmtNode(ImportStmtNode *node)
{
	if (!node) return;
	deleteIdentifierNode(node->name);
	free(node);
}

/**
 * Creates a binding statement.
 *
 * \param [in] binding A pointer to the function that defines the binding.
 *
 * \return A pointer to a binding statement with the desired properties.
 *
 * \retval NULL Memory allocation failed.
 */
BindingStmtNode *createBindingStmtNode(struct returnobject *(*binding)(struct scopeobject *))
{
	BindingStmtNode *p = malloc(sizeof(BindingStmtNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->binding = binding;
	return p;
}

/**
 * Deletes a binding statement.
 *
 * \param [in,out] node The binding statement to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteBindingStmtNode(BindingStmtNode *node)
{
	if (!node) return;
	free(node);
}

/**
 * Creates an expression.
 *
 * \param [in] type The type of expression.
 *
 * \param [in] expr The expression data.
 *
 * \return A pointer to an expression with the desired properties.
 *
 * \retval NULL Memory allocation failed.
 */
ExprNode *createExprNode(ExprType type,
                         void *expr)
{
	ExprNode *p = malloc(sizeof(ExprNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->type = type;
	p->expr = expr;
	return p;
}

/**
 * Deletes an expression.
 *
 * \param [in,out] node The expression to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteExprNode(ExprNode *node)
{
	if (!node) return;
	switch (node->type) {
		case ET_CAST:
			deleteCastExprNode((CastExprNode *)node->expr);
			break;
		case ET_CONSTANT:
			deleteConstantNode((ConstantNode *)node->expr);
			break;
		case ET_IDENTIFIER:
			deleteIdentifierNode((IdentifierNode *)node->expr);
			break;
		case ET_FUNCCALL:
			deleteFuncCallExprNode((FuncCallExprNode *)node->expr);
			break;
		case ET_OP:
			deleteOpExprNode((OpExprNode *)node->expr);
			break;
		case ET_IMPVAR:
			break; /* This expression type does not have any content */
		case ET_SYSTEMCOMMAND:
			deleteSystemCommandExprNode((SystemCommandExprNode *)node->expr);
			break;
		default:
			error(PR_UNKNOWN_EXPRESSION_TYPE);
			break;
	}
	free(node);
}

/**
 * Creates an empty expression list.
 *
 * \return A pointer to an empty expression list.
 *
 * \retval NULL Memory allocation failed.
 */
ExprNodeList *createExprNodeList(void)
{
	ExprNodeList *p = malloc(sizeof(ExprNodeList));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->num = 0;
	p->exprs = NULL;
	return p;
}

/**
 * Adds an expression to a list.
 *
 * \param [in,out] list The expression list to add \a node to.
 *
 * \param [in] node The expression to add to \a list.
 *
 * \post \a node will be added to \a list and its size will be updated.
 *
 * \retval 0 Memory allocation failed.
 *
 * \retval 1 \a node was added to \a list.
 */
int addExprNode(ExprNodeList *list,
                ExprNode *node)
{
	unsigned int newsize = list->num + 1;
	void *mem = realloc(list->exprs, sizeof(ExprNode *) * newsize);
	if (!mem) {
		perror("realloc");
		return 0;
	}
	list->exprs = mem;
	list->exprs[list->num] = node;
	list->num = newsize;
	return 1;
}

/**
 * Deletes an expression list.
 *
 * \param [in,out] list The expression list to delete.
 *
 * \post The memory at \a list and all of its members will be freed.
 */
void deleteExprNodeList(ExprNodeList *list)
{
	unsigned int n;
	if (!list) return;
	for (n = 0; n < list->num; n++)
		deleteExprNode(list->exprs[n]);
	free(list->exprs);
	free(list);
}

/**
 * Creates a cast expression.
 *
 * \param [in] target The expression to cast.
 *
 * \param [in] newtype The type to cast \a target to.
 *
 * \return A pointer to a cast expression with the desired properties.
 *
 * \retval NULL Memory allocation failed.
 */
CastExprNode *createCastExprNode(ExprNode *target,
                                 TypeNode *newtype)
{
	CastExprNode *p = malloc(sizeof(CastExprNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->target = target;
	p->newtype = newtype;
	return p;
}

/**
 * Deletes a cast expression.
 *
 * \param [in,out] node The cast expression to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteCastExprNode(CastExprNode *node)
{
	if (!node) return;
	deleteExprNode(node->target);
	deleteTypeNode(node->newtype);
	free(node);
}

/**
 * Creates a function call expression.
 *
 * \param [in] scope The scope to lookup the function in.
 *
 * \param [in] name The name of the function.
 *
 * \param [in] args The arguments to supply the function.
 *
 * \return A pointer to a function call expression with the desired properties.
 *
 * \retval NULL Memory allocation failed.
 */
FuncCallExprNode *createFuncCallExprNode(IdentifierNode *scope,
                                         IdentifierNode *name,
                                         ExprNodeList *args)
{
	FuncCallExprNode *p = malloc(sizeof(FuncCallExprNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->scope = scope;
	p->name = name;
	p->args = args;
	return p;
}

/**
 * Creates a system command expression.
 *
 * \param [in] cmd The command to execute.
 *
 * \return A pointer to a system command expression with the desired properties.
 *
 * \retval NULL Memory allocation failed.
 */
SystemCommandExprNode *createSystemCommandExprNode(ExprNode *cmd)
{
	SystemCommandExprNode *p = malloc(sizeof(SystemCommandExprNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->cmd = cmd;
	return p;
}

/**
 * Deletes a function call expression.
 *
 * \param [in,out] node The function call expression to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteFuncCallExprNode(FuncCallExprNode *node)
{
	if (!node) return;
	deleteIdentifierNode(node->scope);
	deleteIdentifierNode(node->name);
	deleteExprNodeList(node->args);
	free(node);
}

/**
 * Deletes a system command expression.
 *
 * \param [in,out] node The system command expression to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteSystemCommandExprNode(SystemCommandExprNode *node)
{
	if (!node) return;
	deleteExprNode(node->cmd);
	free(node);
}

/**
 * Creates an operation expression.
 *
 * \param [in] type The type of operation to perform.
 *
 * \param [in] args The operands.
 *
 * \return A pointer to an operation expression with the desired properties.
 *
 * \retval NULL Memroy allocation failed.
 */
OpExprNode *createOpExprNode(OpType type,
                             ExprNodeList *args)
{
	OpExprNode *p = malloc(sizeof(OpExprNode));
	if (!p) {
		perror("malloc");
		return NULL;
	}
	p->type = type;
	p->args = args;
	return p;
}

/**
 * Deletes an operation expression.
 *
 * \param [in,out] node The operation expression to delete.
 *
 * \post The memory at \a node and all of its members will be freed.
 */
void deleteOpExprNode(OpExprNode *node)
{
	if (!node) return;
	deleteExprNodeList(node->args);
	free(node);
}

/**
 * Checks if a type of token is at a position in a token list, and if so,
 * advances the position.
 *
 * \param [in,out] tokenp The position in a token list to check.
 *
 * \param [in] token The type of token to check for.
 *
 * \post If the type of \a tokenp is not \a token, \a tokenp will remain
 * unchanged, else, it will point to the token after the one matched.
 *
 * \retval 0 The type of \a tokenp is \a token.
 *
 * \retval 1 The type of \a tokenp is not \a token.
 */
int acceptToken(Token ***tokenp,
                TokenType token)
{
	Token **tokens = *tokenp;
	if ((*tokens)->type != token) return 0;
	tokens++;
	*tokenp = tokens;
	return 1;
}

/**
 * Checks if a type of token is at a position in a token list.
 *
 * \param [in] tokenp The position in a token list to check.
 *
 * \param [in] token The type of token to check for.
 *
 * \post \a tokenp will remain unchanged.
 *
 * \retval 0 The type of \a tokenp is \a token.
 *
 * \retval 1 The type of \a tokenp is not \a token.
 */
int peekToken(Token ***tokenp,
              TokenType token)
{
	Token **tokens = *tokenp;
	if ((*tokens)->type != token) return 0;
	return 1;
}

/**
 * Checks if a type of token is after a position in a token list.
 *
 * \param [in] tokenp The position in a token list to check after.
 *
 * \param [in] token The type of token to check for.
 *
 * \post \a tokenp will remain unchanged.
 *
 * \retval 0 The type of the token after \a tokenp is \a token.
 *
 * \retval 1 The type of the token after \a tokenp is not \a token.
 */
int nextToken(Token ***tokenp,
         TokenType token)
{
	Token **tokens = *tokenp;
	if ((*(tokens + 1))->type != token) return 0;
	return 1;
}

/**
 * A simple wrapper around the global error printing function tailored to
 * general parser errors.
 *
 * \param [in] type The type of error.
 *
 * \param [in] tokens The tokens being parsed when the error occurred.
 */
void parser_error(ErrorType type,
                  Token **tokens)
{
	error(type, (*tokens)->fname, (*tokens)->line, (*tokens)->image);
}

/**
 * A simple wrapper around the global error printing function tailored to
 * expected token parser errors.
 *
 * \param [in] token The expected token's image.
 *
 * \param [in] tokens The tokens being parsed when the error occurred.
 */
void parser_error_expected_token(TokenType token,
                                 Token **tokens)
{
	error(PR_EXPECTED_TOKEN,
			(*tokens)->fname,
			(*tokens)->line,
			keywords[token],
			(*tokens)->image);
}

/**
 * A simple wrapper around the global error printing function tailored to
 * expected two token parser errors.
 *
 * \param [in] token1 The first expected token's image.
 *
 * \param [in] token2 The second expected token's image.
 *
 * \param [in] tokens The tokens being parsed when the error occurred.
 */
void parser_error_expected_either_token(TokenType token1,
                                        TokenType token2,
                                        Token **tokens)
{
	error(PR_EXPECTED_TOKEN,
			(*tokens)->fname,
			(*tokens)->line,
			keywords[token1],
			keywords[token2],
			(*tokens)->image);
}

/**
 * Parses tokens into a constant.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to a constant.
 *
 * \retval NULL Unable to parse.
 */
ConstantNode *parseConstantNode(Token ***tokenp)
{
	ConstantNode *ret = NULL;
	char *data = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	shiftout();
#endif

	/* Boolean */
	if (peekToken(&tokens, TT_BOOLEAN)) {
#ifdef DEBUG
		debug("CT_BOOLEAN");
#endif
		/* Create the ConstantNode structure */
		ret = createBooleanConstantNode((*tokens)->data.i);
		if (!ret) goto parseConstantNodeAbort;

		/* This should succeed; it was checked for above */
		status = acceptToken(&tokens, TT_BOOLEAN);
		if (!status) {
			parser_error(PR_EXPECTED_BOOLEAN, tokens);
			goto parseConstantNodeAbort;
		}
	}
	/* Integer */
	else if (peekToken(&tokens, TT_INTEGER)) {
#ifdef DEBUG
		debug("CT_INTEGER");
#endif
		/* Create the ConstantNode structure */
		ret = createIntegerConstantNode((*tokens)->data.i);
		if (!ret) goto parseConstantNodeAbort;

		/* This should succeed; it was checked for above */
		status = acceptToken(&tokens, TT_INTEGER);
		if (!status) {
			parser_error(PR_EXPECTED_INTEGER, tokens);
			goto parseConstantNodeAbort;
		}
	}
	/* Float */
	else if (peekToken(&tokens, TT_FLOAT)) {
#ifdef DEBUG
		debug("CT_FLOAT");
#endif
		/* Create the ConstantNode structure */
		ret = createFloatConstantNode((*tokens)->data.f);
		if (!ret) goto parseConstantNodeAbort;

		/* This should succeed; it was checked for above */
		status = acceptToken(&tokens, TT_FLOAT);
		if (!status) {
			parser_error(PR_EXPECTED_FLOAT, tokens);
			goto parseConstantNodeAbort;
		}
	}
	/* String */
	else if (peekToken(&tokens, TT_STRING)) {
		size_t len = strlen((*tokens)->image);
		data = malloc(sizeof(char) * (len - 1));
		if (!data) {
			perror("malloc");
			goto parseConstantNodeAbort;
		}
		strncpy(data, (*tokens)->image + 1, len - 2);
		data[len - 2] = '\0';
#ifdef DEBUG
		debug("CT_STRING");
#endif
		/* Create the ConstantNode structure */
		ret = createStringConstantNode(data);
		if (!ret) goto parseConstantNodeAbort;
		data = NULL;

		/* This should succeed; it was checked for above */
		status = acceptToken(&tokens, TT_STRING);
		if (!status) {
			parser_error(PR_EXPECTED_STRING, tokens);
			goto parseConstantNodeAbort;
		}
	}
	else {
		parser_error(PR_EXPECTED_CONSTANT, tokens);
	}

#ifdef DEBUG
	shiftin();
#endif

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseConstantNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (data) free(data);
	if (ret) deleteConstantNode(ret);

	return NULL;
}

/**
 * Parses tokens into a type.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to a type.
 *
 * \retval NULL Unable to parse.
 */
TypeNode *parseTypeNode(Token ***tokenp)
{
	TypeNode *ret = NULL;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	shiftout();
#endif

	/* Nil */
	if (acceptToken(&tokens, TT_NOOB)) {
#ifdef DEBUG
		debug("CT_NIL");
#endif
		ret = createTypeNode(CT_NIL);
		if (!ret) goto parseTypeNodeAbort;
	}
	/* Boolean */
	else if (acceptToken(&tokens, TT_TROOF)) {
#ifdef DEBUG
		debug("CT_BOOLEAN");
#endif
		ret = createTypeNode(CT_BOOLEAN);
		if (!ret) goto parseTypeNodeAbort;
	}
	/* Integer */
	else if (acceptToken(&tokens, TT_NUMBR)) {
#ifdef DEBUG
		debug("CT_INTEGER");
#endif
		ret = createTypeNode(CT_INTEGER);
		if (!ret) goto parseTypeNodeAbort;
	}
	/* Float */
	else if (acceptToken(&tokens, TT_NUMBAR)) {
#ifdef DEBUG
		debug("CT_FLOAT");
#endif
		ret = createTypeNode(CT_FLOAT);
		if (!ret) goto parseTypeNodeAbort;
	}
	/* String */
	else if (acceptToken(&tokens, TT_YARN)) {
#ifdef DEBUG
		debug("CT_STRING");
#endif
		ret = createTypeNode(CT_STRING);
		if (!ret) goto parseTypeNodeAbort;
	}
	/* Associative array */
	else if (acceptToken(&tokens, TT_BUKKIT)) {
#ifdef DEBUG
		debug("CT_ARRAY");
#endif
		ret = createTypeNode(CT_ARRAY);
		if (!ret) goto parseTypeNodeAbort;
	}
	else {
		parser_error(PR_EXPECTED_TYPE, tokens);
	}

#ifdef DEBUG
	shiftin();
#endif

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseTypeNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteTypeNode(ret);

	return NULL;
}

/**
 * Parses tokens into an identifier.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to an identifier.
 *
 * \retval NULL Unable to parse.
 */
IdentifierNode *parseIdentifierNode(Token ***tokenp)
{
	IdentifierType type;
	void *data = NULL;
	IdentifierNode *slot = NULL;
	const char *fname = NULL;
	unsigned int line;

	/* For direct identifier */
	char *temp = NULL;

	/* For indirect identifier */
	ExprNode *expr = NULL;

	IdentifierNode *ret = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	shiftout();
#endif

	fname = (*tokens)->fname;
	line = (*tokens)->line;

	/* Direct identifier */
	if (peekToken(&tokens, TT_IDENTIFIER)) {
		type = IT_DIRECT;
#ifdef DEBUG
		debug("IT_DIRECT");
#endif
		/* Copy the token image */
		temp = malloc(sizeof(char) * (strlen((*tokens)->image) + 1));
		if (!temp) goto parseIdentifierNodeAbort;
		strcpy(temp, (*tokens)->image);
		data = temp;

		/* This should succeed; it was checked for above */
		status = acceptToken(&tokens, TT_IDENTIFIER);
		if (!status) {
			parser_error(PR_EXPECTED_IDENTIFIER, tokens);
			goto parseIdentifierNodeAbort;
		}
	}
	else if (acceptToken(&tokens, TT_SRS)) {
		type = IT_INDIRECT;
#ifdef DEBUG
		debug("IT_INDIRECT");
#endif
		/* Parse the expression representing the identifier */
		expr = parseExprNode(&tokens);
		if (!expr) goto parseIdentifierNodeAbort;
		data = expr;
	}
	else {
		parser_error(PR_EXPECTED_IDENTIFIER, tokens);
	}

	/* Check if there is a slot access */
	if (acceptToken(&tokens, TT_APOSTROPHEZ)) {
		slot = parseIdentifierNode(&tokens);
		if (!slot) goto parseIdentifierNodeAbort;
	}

#ifdef DEBUG
	shiftin();
#endif

	/* Create the new IdentifierNode structure */
	ret = createIdentifierNode(type, data, slot, fname, line);
	if (!ret) goto parseIdentifierNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseIdentifierNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteIdentifierNode(ret);
	else {
		/* For indirect identifier */
		if (expr) deleteExprNode(expr);

		/* For direct identifier */
		if (temp) free(temp);

		if (slot) deleteIdentifierNode(slot);
	}

	return NULL;
}

/**
 * Parses tokens into a cast expression.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to a cast expression.
 *
 * \retval NULL Unable to parse.
 */
ExprNode *parseCastExprNode(Token ***tokenp)
{
	ExprNode *target = NULL;
	TypeNode *newtype = NULL;
	CastExprNode *expr = NULL;
	ExprNode *ret = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	debug("ET_CAST");
#endif

	/* Parse the cast token */
	status = acceptToken(&tokens, TT_MAEK);
	if (!status) {
		parser_error_expected_token(TT_MAEK, tokens);
		goto parseCastExprNodeAbort;
	}

	/* Parse the expression to cast */
	target = parseExprNode(&tokens);
	if (!target) goto parseCastExprNodeAbort;

	/* Optionally parse the cast-to token */
	status = acceptToken(&tokens, TT_A);

	/* Parse the type to cast to */
	newtype = parseTypeNode(&tokens);
	if (!newtype) goto parseCastExprNodeAbort;

	/* Create the new CastExprNode structure */
	expr = createCastExprNode(target, newtype);
	if (!expr) goto parseCastExprNodeAbort;

	/* Create the new ExprNode structure */
	ret = createExprNode(ET_CAST, expr);
	if (!ret) goto parseCastExprNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseCastExprNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteExprNode(ret);
	else if (expr) deleteCastExprNode(expr);
	else {
		if (newtype) deleteTypeNode(newtype);
		if (target) deleteExprNode(target);
	}

	return NULL;
}

/**
 * Parses tokens into a constant expression.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to a constant expression.
 *
 * \retval NULL Unable to parse.
 */
ExprNode *parseConstantExprNode(Token ***tokenp)
{
	ConstantNode *node = NULL;
	ExprNode *ret = NULL;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	debug("ET_CONSTANT");
#endif

	/* Parse the constant */
	node = parseConstantNode(&tokens);
	if (!node) goto parseConstantExprNodeAbort;

	/* Create the new ExprNode structure */
	ret = createExprNode(ET_CONSTANT, node);
	if (!ret) goto parseConstantExprNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseConstantExprNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteExprNode(ret);
	else {
		if (node) deleteConstantNode(node);
	}

	return NULL;
}

/**
 * Parses tokens into an identifier expression.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to an identifier expression.
 *
 * \retval NULL Unable to parse.
 */
ExprNode *parseIdentifierExprNode(Token ***tokenp)
{
	IdentifierNode *node = NULL;
	ExprNode *ret = NULL;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	debug("ET_IDENTIFIER");
#endif

	/* Parse the identifier node */
	node = parseIdentifierNode(&tokens);
	if (!node) goto parseIdentifierExprNodeAbort;

	/* Create the new ExprNode structure */
	ret = createExprNode(ET_IDENTIFIER, node);
	if (!ret) goto parseIdentifierExprNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseIdentifierExprNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteExprNode(ret);
	else {
		if (node) deleteIdentifierNode(node);
	}

	return NULL;
}

/**
 * Parses tokens into a function call expression.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a Tokenp will point to the next unparsed token.
 *
 * \return A pointer to a function call expression.
 *
 * \retval NULL Unable to parse.
 */
ExprNode *parseFuncCallExprNode(Token ***tokenp)
{
	IdentifierNode *scope = NULL;
	IdentifierNode *name = NULL;
	ExprNodeList *args = NULL;
	ExprNode *arg = NULL;
	FuncCallExprNode *expr = NULL;
	ExprNode *ret = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	debug("ET_FUNCCALL");
#endif

	/* Parse the scope name */
	scope = parseIdentifierNode(&tokens);
	if (!scope) goto parseFuncCallExprNodeAbort;

	/* Parse the function call token */
	status = acceptToken(&tokens, TT_IZ);
	if (!status) {
		parser_error_expected_token(TT_IZ, tokens);
		goto parseFuncCallExprNodeAbort;
	}

	/* Parse the function name */
	name = parseIdentifierNode(&tokens);
	if (!name) goto parseFuncCallExprNodeAbort;

	/* Create an argument list */
	args = createExprNodeList();
	if (!args) goto parseFuncCallExprNodeAbort;

	/* Parse the first argument token */
	if (acceptToken(&tokens, TT_YR)) {
		/* Parse the first argument */
		arg = parseExprNode(&tokens);
		if (!arg) goto parseFuncCallExprNodeAbort;

		/* Add the first argument to the argument list */
		status = addExprNode(args, arg);
		if (!status) goto parseFuncCallExprNodeAbort;
		arg = NULL;

		/* Parse additional arguments */
		while (acceptToken(&tokens, TT_ANYR)) {
			/* Parse the argument */
			arg = parseExprNode(&tokens);
			if (!arg) goto parseFuncCallExprNodeAbort;

			/* Add the argument to the argument list */
			status = addExprNode(args, arg);
			if (!status) goto parseFuncCallExprNodeAbort;
			arg = NULL;
		}
	}

	/* Parse the end-of-argument token */
	status = acceptToken(&tokens, TT_MKAY);
	if (!status) {
		parser_error_expected_token(TT_MKAY, tokens);
		goto parseFuncCallExprNodeAbort;
	}

	/* Create the new FuncCallExprNode structure */
	expr = createFuncCallExprNode(scope, name, args);
	if (!expr) goto parseFuncCallExprNodeAbort;

	/* Create the new ExprNode structure */
	ret = createExprNode(ET_FUNCCALL, expr);
	if (!ret) goto parseFuncCallExprNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseFuncCallExprNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteExprNode(ret);
	else if (expr) deleteFuncCallExprNode(expr);
	else {
		if (args) deleteExprNodeList(args);
		if (arg) deleteExprNode(arg);
		if (name) deleteIdentifierNode(name);
		if (scope) deleteIdentifierNode(scope);
	}

	return NULL;
}

/**
 * Parses tokens into a system command expression.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a Tokenp will point to the next unparsed token.
 *
 * \return A pointer to a system command expression.
 *
 * \retval NULL Unable to parse.
 */
ExprNode *parseSystemCommandExprNode(Token ***tokenp)
{
	ExprNode *name = NULL;
	SystemCommandExprNode *expr = NULL;
	ExprNode *ret = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	debug("ET_SYSTEMCOMMAND");
#endif

	/* Parse the system command token */
	status = acceptToken(&tokens, TT_IDUZ);
	if (!status) {
		parser_error_expected_token(TT_IDUZ, tokens);
		goto parseSystemCommandExprNodeAbort;
	}

	/* Parse the expression name */
	name = parseExprNode(&tokens);
        if (!name) goto parseSystemCommandExprNodeAbort;

	/* Create the new SystemCommandExprNode structure */
	expr = createSystemCommandExprNode(name);
	if (!expr) goto parseSystemCommandExprNodeAbort;

	/* Create the new ExprNode structure */
	ret = createExprNode(ET_SYSTEMCOMMAND, expr);
	if (!ret) goto parseSystemCommandExprNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseSystemCommandExprNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteExprNode(ret);
	else if (expr) deleteSystemCommandExprNode(expr);
	else if (name) deleteExprNode(name);

	return NULL;
}

/**
 * Parses tokens into an operation expression.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to a operation expression.
 *
 * \retval NULL Unable to parse.
 */
ExprNode *parseOpExprNode(Token ***tokenp)
{
	enum ArityType {
		AT_UNARY,
		AT_BINARY,
		AT_NARY
	};
	enum ArityType arity;
	ExprNodeList *args = NULL;
	ExprNode *arg = NULL;
	OpExprNode *expr = NULL;
	OpType type;
	ExprNode *ret = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

	/* Unary operations */
	if (acceptToken(&tokens, TT_NOT)) {
		type = OP_NOT;
		arity = AT_UNARY;
#ifdef DEBUG
		debug("ET_OP (OP_NOT)");
#endif
	}
	/* Binary operations */
	else if (acceptToken(&tokens, TT_SUMOF)) {
		type = OP_ADD;
		arity = AT_BINARY;
#ifdef DEBUG
		debug("ET_OP (OP_ADD)");
#endif
	}
	else if(acceptToken(&tokens, TT_DIFFOF)) {
		type = OP_SUB;
		arity = AT_BINARY;
#ifdef DEBUG
		debug("ET_OP (OP_SUB)");
#endif
	}
	else if(acceptToken(&tokens, TT_PRODUKTOF)) {
		type = OP_MULT;
		arity = AT_BINARY;
#ifdef DEBUG
		debug("ET_OP (OP_MULT)");
#endif
	}
	else if(acceptToken(&tokens, TT_QUOSHUNTOF)) {
		type = OP_DIV;
		arity = AT_BINARY;
#ifdef DEBUG
		debug("ET_OP (OP_DIV)");
#endif
	}
	else if(acceptToken(&tokens, TT_MODOF)) {
		type = OP_MOD;
		arity = AT_BINARY;
#ifdef DEBUG
		debug("ET_OP (OP_MOD)");
#endif
	}
	else if(acceptToken(&tokens, TT_BIGGROF)) {
		type = OP_MAX;
		arity = AT_BINARY;
#ifdef DEBUG
		debug("ET_OP (OP_MAX)");
#endif
	}
	else if(acceptToken(&tokens, TT_SMALLROF)) {
		type = OP_MIN;
		arity = AT_BINARY;
#ifdef DEBUG
		debug("ET_OP (OP_MIN)");
#endif
	}
	else if(acceptToken(&tokens, TT_BOTHOF)) {
		type = OP_AND;
		arity = AT_BINARY;
#ifdef DEBUG
		debug("ET_OP (OP_AND)");
#endif
	}
	else if(acceptToken(&tokens, TT_EITHEROF)) {
		type = OP_OR;
		arity = AT_BINARY;
#ifdef DEBUG
		debug("ET_OP (OP_OR)");
#endif
	}
	else if(acceptToken(&tokens, TT_WONOF)) {
		type = OP_XOR;
		arity = AT_BINARY;
#ifdef DEBUG
		debug("ET_OP (OP_XOR)");
#endif
	}
	else if(acceptToken(&tokens, TT_BOTHSAEM)) {
		type = OP_EQ;
		arity = AT_BINARY;
#ifdef DEBUG
		debug("ET_OP (OP_EQ)");
#endif
	}
	else if(acceptToken(&tokens, TT_DIFFRINT)) {
		type = OP_NEQ;
		arity = AT_BINARY;
#ifdef DEBUG
		debug("ET_OP (OP_NEQ)");
#endif
	}
	/* N-ary operators */
	else if (acceptToken(&tokens, TT_ALLOF)) {
		type = OP_AND;
		arity = AT_NARY;
#ifdef DEBUG
		debug("ET_OP (OP_AND)");
#endif
	}
	else if(acceptToken(&tokens, TT_ANYOF)) {
		type = OP_OR;
		arity = AT_NARY;
#ifdef DEBUG
		debug("ET_OP (OP_OR)");
#endif
	}
	else if(acceptToken(&tokens, TT_SMOOSH)) {
		type = OP_CAT;
		arity = AT_NARY;
#ifdef DEBUG
		debug("ET_OP (OP_CAT)");
#endif
	}
	else {
		parser_error(PR_INVALID_OPERATOR, tokens);
		return NULL;
	}

	/* Create the argument list */
	args = createExprNodeList();
	if (!args) goto parseOpExprNodeAbort;

	/* Parse the operation arguments */
	if (arity == AT_UNARY) {
		/* Parse the argument */
		arg = parseExprNode(&tokens);
		if (!arg) goto parseOpExprNodeAbort;

		/* Add the argument to the argument list */
		status = addExprNode(args, arg);
		if (!status) goto parseOpExprNodeAbort;
		arg = NULL;
	}
	else if (arity == AT_BINARY) {
		/* Parse the first argument */
		arg = parseExprNode(&tokens);
		if (!arg) goto parseOpExprNodeAbort;

		/* Add the first argument to the argument list */
		status = addExprNode(args, arg);
		if (!status) goto parseOpExprNodeAbort;
		arg = NULL;

		/* Optionally parse the argument-separator token */
		status = acceptToken(&tokens, TT_AN);

		/* Parse the second argument */
		arg = parseExprNode(&tokens);
		if (!arg) goto parseOpExprNodeAbort;

		/* Add the second argument to the argument list */
		status = addExprNode(args, arg);
		if (!status) goto parseOpExprNodeAbort;
		arg = NULL;
	}
	else if (arity == AT_NARY) {
		/* Parse as many arguments as possible */
		while (1) {
			/* Parse an argument */
			arg = parseExprNode(&tokens);
			if (!arg) goto parseOpExprNodeAbort;

			/* Add the argument to the argument list */
			status = addExprNode(args, arg);
			if (!status) goto parseOpExprNodeAbort;
			arg = NULL;
			
			/* Stop if the end-of-arguments token is present */
			if (acceptToken(&tokens, TT_MKAY)) break;

			/* Optionally parse the argument-separator token */
			status = acceptToken(&tokens, TT_AN);
		}
	}

	/* Create the new OpExprNode structure */
	expr = createOpExprNode(type, args);
	if (!expr) goto parseOpExprNodeAbort;

	/* Create the new ExprNode structure */
	ret = createExprNode(ET_OP, expr);
	if (!ret) goto parseOpExprNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseOpExprNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteExprNode(ret);
	else if (expr) deleteOpExprNode(expr);
	else {
		if (arg) deleteExprNode(arg);
		if (args) deleteExprNodeList(args);
	}

	return NULL;
}

/**
 * Parses tokens into an expression.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to an expression.
 *
 * \retval NULL Unable to parse.
 */
ExprNode *parseExprNode(Token ***tokenp)
{
	Token **tokens = *tokenp;
	ExprNode *ret = NULL;

#ifdef DEBUG
	shiftout();
#endif

	/* Parse context-sensitive expressions */
	if (peekToken(&tokens, TT_IDENTIFIER)
			|| peekToken(&tokens, TT_SRS)) {
		IdentifierNode *id = NULL;

		/* Remove the identifier from the token stream */
		id = parseIdentifierNode(&tokens);
		if (!id) return NULL;

		/* We do not need to hold onto it */
		deleteIdentifierNode(id);

		/* Function call (must come before identifier) */
		if (peekToken(&tokens, TT_IZ)) {
			ret = parseFuncCallExprNode(tokenp);
		}
		/* Identifier */
		else {
			ret = parseIdentifierExprNode(tokenp);
		}
	}
	/* Cast */
	else if (peekToken(&tokens, TT_MAEK)) {
		ret = parseCastExprNode(tokenp);
	}
	/* Constant value */
	else if (peekToken(&tokens, TT_BOOLEAN)
			|| peekToken(&tokens, TT_INTEGER)
			|| peekToken(&tokens, TT_FLOAT)
			|| peekToken(&tokens, TT_STRING))
		ret = parseConstantExprNode(tokenp);
	/* Operation */
	else if (peekToken(&tokens, TT_SUMOF)
			|| peekToken(&tokens, TT_DIFFOF)
			|| peekToken(&tokens, TT_PRODUKTOF)
			|| peekToken(&tokens, TT_QUOSHUNTOF)
			|| peekToken(&tokens, TT_MODOF)
			|| peekToken(&tokens, TT_BIGGROF)
			|| peekToken(&tokens, TT_SMALLROF)
			|| peekToken(&tokens, TT_BOTHOF)
			|| peekToken(&tokens, TT_EITHEROF)
			|| peekToken(&tokens, TT_WONOF)
			|| peekToken(&tokens, TT_BOTHSAEM)
			|| peekToken(&tokens, TT_DIFFRINT)
			|| peekToken(&tokens, TT_ANYOF)
			|| peekToken(&tokens, TT_ALLOF)
			|| peekToken(&tokens, TT_SMOOSH)
			|| peekToken(&tokens, TT_NOT)) {
		ret = parseOpExprNode(tokenp);
	}
	/* Implicit variable */
	else if (acceptToken(&tokens, TT_IT)) {
#ifdef DEBUG
		debug("ET_IMPVAR");
#endif

		/* Create the new ExprNode structure */
		ret = createExprNode(ET_IMPVAR, NULL);
		if (!ret) return NULL;

		/* Since we're successful, update the token stream */
		*tokenp = tokens;
	}
	else if (peekToken(&tokens, TT_IDUZ)) {
		/* System command */
		ret = parseSystemCommandExprNode(tokenp);
	}
	else {
		parser_error(PR_EXPECTED_EXPRESSION, tokens);
	}

#ifdef DEBUG
	shiftin();
#endif

	return ret;
}

/**
 * Parses tokens into a cast statement.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to a cast statement.
 *
 * \retval NULL Unable to parse.
 */
StmtNode *parseCastStmtNode(Token ***tokenp)
{
	IdentifierNode *target = NULL;
	TypeNode *newtype = NULL;
	CastStmtNode *stmt = NULL;
	StmtNode *ret = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	debug("ST_CAST");
#endif

	/* Parse the target of the cast statement */
	target = parseIdentifierNode(&tokens);
	if (!target) goto parseCastStmtNodeAbort;

	/* Remove the cast keywords from the token stream */
	status = acceptToken(&tokens, TT_ISNOWA);
	if (!status) {
		parser_error_expected_token(TT_ISNOWA, tokens);
		goto parseCastStmtNodeAbort;
	}

	/* Parse the type to cast to */
	newtype = parseTypeNode(&tokens);
	if (!newtype) goto parseCastStmtNodeAbort;

	/* Make sure the statement ends with a newline */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_EXPRESSION, tokens);
		goto parseCastStmtNodeAbort;
	}

	/* Create the new CastStmtNode structure */
	stmt = createCastStmtNode(target, newtype);
	if (!stmt) goto parseCastStmtNodeAbort;

	/* Create the new StmtNode structure */
	ret = createStmtNode(ST_CAST, stmt);
	if (!ret) goto parseCastStmtNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseCastStmtNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteStmtNode(ret);
	else if (stmt) deleteCastStmtNode(stmt);
	else {
		if (newtype) deleteTypeNode(newtype);
		if (target) deleteIdentifierNode(target);
	}

	return NULL;
}

/**
 * Parses tokens into a print statement.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to a print statement.
 *
 * \retval NULL Unable to parse.
 */
StmtNode *parsePrintStmtNode(Token ***tokenp)
{
	ExprNode *arg = NULL;
	ExprNodeList *args = NULL;
	int nonl = 0;
	PrintStmtNode *stmt = NULL;
	StmtNode *ret = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	debug("ST_PRINT");
#endif

	/* Remove the print keyword from the token stream */
	status = acceptToken(&tokens, TT_VISIBLE);
	if (!status) {
		parser_error_expected_token(TT_VISIBLE, tokens);
		goto parsePrintStmtNodeAbort;
	}

	/* Parse the arguments to the print statement */
	args = createExprNodeList();
	if (!args) goto parsePrintStmtNodeAbort;
	do {
		/* Parse an argument; it should be an expression */
		arg = parseExprNode(&tokens);
		if (!arg) goto parsePrintStmtNodeAbort;

		/* Add it to the list of arguments */
		status = addExprNode(args, arg);
		if (!status) goto parsePrintStmtNodeAbort;
		arg = NULL;

		/* Arguments can optionally be separated by an AN keyword */
		status = acceptToken(&tokens, TT_AN);
	} while (!peekToken(&tokens, TT_NEWLINE)
			&& !peekToken(&tokens, TT_BANG));

	/* Check for the no-newline token */
	if(acceptToken(&tokens, TT_BANG)) nonl = 1;

	/* Make sure the statement ends with a newline */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_EXPRESSION, tokens);
		goto parsePrintStmtNodeAbort;
	}

	/* Create the new PrintStmtNode structure */
	stmt = createPrintStmtNode(args, nonl);
	if (!stmt) goto parsePrintStmtNodeAbort;

	/* Create the new StmtNode structure */
	ret = createStmtNode(ST_PRINT, stmt);
	if (!ret) goto parsePrintStmtNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parsePrintStmtNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteStmtNode(ret);
	else if (stmt) deletePrintStmtNode(stmt);
	else {
		if (arg) deleteExprNode(arg);
		if (args) deleteExprNodeList(args);
	}

	return NULL;
}

/**
 * Parses tokens into an input statement.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to an input statement.
 *
 * \retval NULL Unable to parse.
 */
StmtNode *parseInputStmtNode(Token ***tokenp)
{
	IdentifierNode *target = NULL;
	InputStmtNode *stmt = NULL;
	StmtNode *ret = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	debug("ST_INPUT");
#endif

	/* Remove the input keyword from the token stream */
	status = acceptToken(&tokens, TT_GIMMEH);
	if (!status) {
		parser_error_expected_token(TT_GIMMEH, tokens);
		goto parseInputStmtNodeAbort;
	}

	/* Parse the identifier to store the input into */
	target = parseIdentifierNode(&tokens);
	if (!target) goto parseInputStmtNodeAbort;

	/* Make sure the statement ends with a newline */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_EXPRESSION, tokens);
		goto parseInputStmtNodeAbort;
	}

	/* Create the new InputStmtNode structure */
	stmt = createInputStmtNode(target);
	if (!stmt) goto parseInputStmtNodeAbort;

	/* Create the new StmtNode structure */
	ret = createStmtNode(ST_INPUT, stmt);
	if (!ret) goto parseInputStmtNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseInputStmtNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteStmtNode(ret);
	else if (stmt) deleteInputStmtNode(stmt);
	else {
		if (target) deleteIdentifierNode(target);
	}

	return NULL;
}

/**
 * Parses tokens into an assignment statement.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to an assignment statement.
 *
 * \retval NULL unable to parse.
 */ 
StmtNode *parseAssignmentStmtNode(Token ***tokenp)
{
	IdentifierNode *target = NULL;
	ExprNode *expr = NULL;
	AssignmentStmtNode *stmt = NULL;
	StmtNode *ret = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	debug("ST_ASSIGNMENT");
#endif

	/* Parse the target of the assignment */
	target = parseIdentifierNode(&tokens);
	if (!target) goto parseAssignmentStmtNodeAbort;

	/* Remove the assignment keyword from the token stream */
	if (!acceptToken(&tokens, TT_R)) {
		parser_error_expected_token(TT_R, tokens);
		goto parseAssignmentStmtNodeAbort;
	}

	/* Parse the expression to assign */
	expr = parseExprNode(&tokens);
	if (!expr) goto parseAssignmentStmtNodeAbort;

	/* Make sure the statement ends with a newline */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_STATEMENT, tokens);
		goto parseAssignmentStmtNodeAbort;
	}

	/* Create the new AssignmentStmtNode structure */
	stmt = createAssignmentStmtNode(target, expr);
	if (!stmt) goto parseAssignmentStmtNodeAbort;

	/* Create the new StmtNode structure */
	ret = createStmtNode(ST_ASSIGNMENT, stmt);
	if (!ret) goto parseAssignmentStmtNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseAssignmentStmtNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteStmtNode(ret);
	else if (stmt) deleteAssignmentStmtNode(stmt);
	else {
		if (expr) deleteExprNode(expr);
		if (target) deleteIdentifierNode(target);
	}

	return NULL;
}

/**
 * Parses tokens into a declaration statement.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to a declaration statement.
 *
 * \retval NULL Unable to parse.
 */
StmtNode *parseDeclarationStmtNode(Token ***tokenp)
{
	IdentifierNode *scope = NULL;
	IdentifierNode *target = NULL;
	ExprNode *expr = NULL;
	TypeNode *type = NULL;
	IdentifierNode *parent = NULL;
	DeclarationStmtNode *stmt = NULL;
	StmtNode *ret = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	debug("ST_DECLARATION");
#endif

	/* Parse the scope to declare the variable in */
	scope = parseIdentifierNode(&tokens);
	if (!scope) goto parseDeclarationStmtNodeAbort;

	/* Remove the declaration keywords from the token stream */
	if (!acceptToken(&tokens, TT_HASA)) {
		parser_error_expected_token(TT_HASA, tokens);
		goto parseDeclarationStmtNodeAbort;
	}

	/* Parse the identifier to declare */
	target = parseIdentifierNode(&tokens);
	if (!target) goto parseDeclarationStmtNodeAbort;

	/* Check for an optional initialization */
	if (acceptToken(&tokens, TT_ITZ)) {
		/* Parse the expression to initialize to */
		expr = parseExprNode(&tokens);
		if (!expr) goto parseDeclarationStmtNodeAbort;
	}
	/* Check for an optional type initialization */
	else if (acceptToken(&tokens, TT_ITZA)) {
		/* Parse the type to initialize to */
		type = parseTypeNode(&tokens);
		if (!type) goto parseDeclarationStmtNodeAbort;
	}
	/* Check for an optional array inheritance */
	else if (acceptToken(&tokens, TT_ITZLIEKA)) {
		/* Parse the parent to inherit from */
		parent = parseIdentifierNode(&tokens);
		if (!parent) goto parseDeclarationStmtNodeAbort;
	}

	/* Make sure the statement ends with a newline */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_STATEMENT, tokens);
		goto parseDeclarationStmtNodeAbort;
	}

	/* Create the new DeclarationStmtNode structure */
	stmt = createDeclarationStmtNode(scope, target, expr, type, parent);
	if (!stmt) goto parseDeclarationStmtNodeAbort;

	/* Create the new StmtNode structure */
	ret = createStmtNode(ST_DECLARATION, stmt); 
	if (!ret) goto parseDeclarationStmtNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseDeclarationStmtNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteStmtNode(ret);
	else if (stmt) deleteDeclarationStmtNode(stmt);
	else {
		if (type) deleteTypeNode(type);
		if (expr) deleteExprNode(expr);
		if (target) deleteIdentifierNode(target);
		if (scope) deleteIdentifierNode(scope);
	}

	return NULL;
}

/**
 * Parses tokens into an if/then/else statement.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to an if/then/else statement.
 *
 * \retval NULL Unable to parse.
 */
StmtNode *parseIfThenElseStmtNode(Token ***tokenp)
{
	BlockNode *yes = NULL;
	ExprNodeList *guards = NULL;
	BlockNodeList *blocks = NULL;
	ExprNode *guard = NULL;
	BlockNode *block = NULL;
	BlockNode *no = NULL;
	IfThenElseStmtNode *stmt = NULL;
	StmtNode *ret = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	debug("ST_CONDITIONAL");
#endif

	/* Remove the if keyword from the token stream */
	status = acceptToken(&tokens, TT_ORLY);
	if (!status) {
		parser_error_expected_token(TT_ORLY, tokens);
		goto parseIfThenElseStmtNodeAbort;
	}

	/* Remove the question mark from the token stream */
	status = acceptToken(&tokens, TT_QUESTION);
	if (!status) {
		parser_error_expected_token(TT_QUESTION, tokens);
		goto parseIfThenElseStmtNodeAbort;
	}

	/* The if keyword must appear on its own line */
	if (!acceptToken(&tokens, TT_NEWLINE)) {
		parser_error(PR_EXPECTED_END_OF_EXPRESSION, tokens);
		goto parseIfThenElseStmtNodeAbort;
	}

	/* Parse the true branch keyword */
	status = acceptToken(&tokens, TT_YARLY);
	if (!status) {
		parser_error_expected_token(TT_YARLY, tokens);
		goto parseIfThenElseStmtNodeAbort;
	}

	/* The true branch keyword must appear on its own line */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_EXPRESSION, tokens);
		goto parseIfThenElseStmtNodeAbort;
	}

	/* Parse the true part of the branch */
	yes = parseBlockNode(&tokens);
	if (!yes) goto parseIfThenElseStmtNodeAbort;

	/* Set up lists of guards and blocks */
	guards = createExprNodeList();
	if (!guards) goto parseIfThenElseStmtNodeAbort;
	blocks = createBlockNodeList();
	if (!blocks) goto parseIfThenElseStmtNodeAbort;

	/* Parse the else-if keyword */
	while (acceptToken(&tokens, TT_MEBBE)) {
		/* Parse an else-if guard */
		guard = parseExprNode(&tokens);
		if (!guard) goto parseIfThenElseStmtNodeAbort;

		/* Add the else-if guard to the guard list */
		status = addExprNode(guards, guard);
		if (!status) goto parseIfThenElseStmtNodeAbort;
		guard = NULL;

		/* The else-if keyword and guard must be on their own line */
		status = acceptToken(&tokens, TT_NEWLINE);
		if (!status) {
			parser_error(PR_EXPECTED_END_OF_EXPRESSION, tokens);
			goto parseIfThenElseStmtNodeAbort;
		}

		/* Parse the else-if block */
		block = parseBlockNode(&tokens);
		if (!block) goto parseIfThenElseStmtNodeAbort;

		/* Add the else-if block to the block list */
		status = addBlockNode(blocks, block);
		if (!status) goto parseIfThenElseStmtNodeAbort;
		block = NULL;
	}

	/* Parse the else keyword */
	if (acceptToken(&tokens, TT_NOWAI)) {
		/* The else keyword must appear on its own line */
		status = acceptToken(&tokens, TT_NEWLINE);
		if (!status) {
			parser_error(PR_EXPECTED_END_OF_EXPRESSION, tokens);
			goto parseIfThenElseStmtNodeAbort;
		}

		/* Parse the else block */
		no = parseBlockNode(&tokens);
		if (!no) goto parseIfThenElseStmtNodeAbort;
	}

	/* Parse the end-if-block keyword */
	status = acceptToken(&tokens, TT_OIC);
	if (!status) {
		parser_error_expected_token(TT_OIC, tokens);
		goto parseIfThenElseStmtNodeAbort;
	}

	/* The end-if-block keyword must appear on its own line */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_EXPRESSION, tokens);
		goto parseIfThenElseStmtNodeAbort;
	}

	/* Create the new IfThenElseStmtNode structure */
	stmt = createIfThenElseStmtNode(yes, no, guards, blocks);
	if (!stmt) goto parseIfThenElseStmtNodeAbort;

	/* Create the new StmtNode structure */
	ret = createStmtNode(ST_IFTHENELSE, stmt);
	if (!ret) goto parseIfThenElseStmtNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseIfThenElseStmtNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteStmtNode(ret);
	else if (stmt) deleteIfThenElseStmtNode(stmt);
	else {
		if (no) deleteBlockNode(no);
		if (blocks) deleteBlockNodeList(blocks);
		if (guards) deleteExprNodeList(guards);
		if (block) deleteBlockNode(block);
		if (guard) deleteExprNode(guard);
		if (yes) deleteBlockNode(yes);
	}

	return NULL;
}

/**
 * Parses tokens into a switch statement.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to a switch statement.
 *
 * \retval NULL Unable to parse.
 */
StmtNode *parseSwitchStmtNode(Token ***tokenp)
{
	ExprNodeList *guards = NULL;
	BlockNodeList *blocks = NULL;
	ConstantNode *c = NULL;
	ExprNode *guard = NULL;
	BlockNode *block = NULL;
	BlockNode *def = NULL;
	SwitchStmtNode *stmt = NULL;
	StmtNode *ret = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	debug("ST_SWITCH");
#endif

	/* Remove the switch keyword from the token stream */
	status = acceptToken(&tokens, TT_WTF);
	if (!status) {
		parser_error_expected_token(TT_WTF, tokens);
		goto parseSwitchStmtNodeAbort;
	}

	/* Remove the question mark from the token stream */
	status = acceptToken(&tokens, TT_QUESTION);
	if (!status) {
		parser_error_expected_token(TT_QUESTION, tokens);
		goto parseSwitchStmtNodeAbort;
	}

	/* The switch keyword must appear on its own line */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_EXPRESSION, tokens);
		goto parseSwitchStmtNodeAbort;
	}

	/* Set up lists of guards and blocks */
	guards = createExprNodeList();
	if (!guards) goto parseSwitchStmtNodeAbort;
	blocks = createBlockNodeList();
	if (!blocks) goto parseSwitchStmtNodeAbort;

	/* Parse at least one case */
	do {
		unsigned int n = 0;

		/* Parse the case keyword */
		status = acceptToken(&tokens, TT_OMG);
		if (!status) {
			parser_error_expected_token(TT_OMG, tokens);
			goto parseSwitchStmtNodeAbort;
		}

		/* Parse a constant for the case */
		/** \note The 1.2 specification only allows constant
		 *       values for OMG guards thus this function
		 *       explicitly checks for them. */
		c = parseConstantNode(&tokens);
		if (!c) goto parseSwitchStmtNodeAbort;

		/* String interpolation is not allowed */
		if (c->type == CT_STRING && strstr(c->data.s, ":{")) {
			parser_error(PR_CANNOT_USE_STR_AS_LITERAL, tokens);
			goto parseSwitchStmtNodeAbort;
		}

		/* Make sure the constant is unique to this switch statement */
		for (n = 0; n < guards->num; n++) {
			ConstantNode *test = guards->exprs[n]->expr;
			if (c->type != test->type) continue;
			/* Check for equivalent types and values */
			if (((c->type == CT_BOOLEAN || c->type == CT_INTEGER)
					&& c->data.i == test->data.i)
					|| (c->type == CT_FLOAT
					&& fabs(c->data.f - test->data.f) < FLT_EPSILON)
					|| (c->type == CT_STRING
					&& !strcmp(c->data.s, test->data.s))) {
				parser_error(PR_LITERAL_MUST_BE_UNIQUE, tokens);
				goto parseSwitchStmtNodeAbort;
			}
		}

		/* Package the constant in an expression */
		guard = createExprNode(ET_CONSTANT, c);
		if (!guard) goto parseSwitchStmtNodeAbort;

		/* Add the guard to the list of guards */
		status = addExprNode(guards, guard);
		if (!status) goto parseSwitchStmtNodeAbort;
		guard = NULL;

		/* Make sure the guard appears on its own line */
		status = acceptToken(&tokens, TT_NEWLINE);
		if (!status) {
			parser_error(PR_EXPECTED_END_OF_EXPRESSION, tokens);
			goto parseSwitchStmtNodeAbort;
		}

		/* Parse the block associated with the guard */
		block = parseBlockNode(&tokens);
		if (!block) goto parseSwitchStmtNodeAbort;

		/* Add the block to the list of blocks */
		status = addBlockNode(blocks, block);
		if (!status) goto parseSwitchStmtNodeAbort;
		block = NULL;
	} while (peekToken(&tokens, TT_OMG));

	/* Check for the default case */
	if (acceptToken(&tokens, TT_OMGWTF)) {
		/* Make sure the default case keyword appears on its own line */
		status = acceptToken(&tokens, TT_NEWLINE);
		if (!status) {
			parser_error(PR_EXPECTED_END_OF_EXPRESSION, tokens);
			goto parseSwitchStmtNodeAbort;
		}

		/* Parse the default case block */
		def = parseBlockNode(&tokens);
		if (!def) goto parseSwitchStmtNodeAbort;
	}

	/* Parse the end-switch keyword */
	status = acceptToken(&tokens, TT_OIC);
	if (!status) {
		parser_error_expected_token(TT_OIC, tokens);
		goto parseSwitchStmtNodeAbort;
	}

	/* Make sure the end-switch keyword appears on its own line */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_EXPRESSION, tokens);
		goto parseSwitchStmtNodeAbort;
	}

	/* Create the new SwitchStmtNode structure */
	stmt = createSwitchStmtNode(guards, blocks, def);
	if (!stmt) goto parseSwitchStmtNodeAbort;

	/* Create the new StmtNode structure */
	ret = createStmtNode(ST_SWITCH, stmt);
	if (!ret) goto parseSwitchStmtNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseSwitchStmtNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteStmtNode(ret);
	else if (stmt) deleteSwitchStmtNode(stmt);
	else {
		if (def) deleteBlockNode(def);
		if (block) deleteBlockNode(block);
		if (guard) deleteExprNode(guard);
		if (c) deleteConstantNode(c);
		if (blocks) deleteBlockNodeList(blocks);
		if (guards) deleteExprNodeList(guards);
	}

	return NULL;
}

/**
 * Parses tokens into a break statement.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to a break statement.
 *
 * \retval NULL Unable to parse.
 */
StmtNode *parseBreakStmtNode(Token ***tokenp)
{
	StmtNode *ret = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	debug("ST_BREAK");
#endif

	/* Remove the break keyword from the token stream */
	status = acceptToken(&tokens, TT_GTFO);
	if (!status) {
		parser_error_expected_token(TT_GTFO, tokens);
		goto parseBreakStmtNodeAbort;
	}

	/* The break keyword must appear on its own line */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_EXPRESSION, tokens);
		goto parseBreakStmtNodeAbort;
	}

	/* Create the new StmtNode structure */
	ret = createStmtNode(ST_BREAK, NULL);
	if (!ret) goto parseBreakStmtNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseBreakStmtNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteStmtNode(ret);
	return NULL;
}

/**
 * Parses tokens into a return statement.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to a return statement.
 *
 * \retval NULL Unable to parse.
 */
StmtNode *parseReturnStmtNode(Token ***tokenp)
{
	ExprNode *value = NULL;
	ReturnStmtNode *stmt = NULL;
	StmtNode *ret = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	debug("ST_RETURN");
#endif

	/* Remove the return keyword from the token stream */
	status = acceptToken(&tokens, TT_FOUNDYR);
	if (!status) {
		parser_error_expected_token(TT_FOUNDYR, tokens);
		goto parseReturnStmtNodeAbort;
	}

	/* Parse the return value */
	value = parseExprNode(&tokens);
	if (!value) goto parseReturnStmtNodeAbort;

	/* The return statement must reside on its own line */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_EXPRESSION, tokens);
		goto parseReturnStmtNodeAbort;
	}

	/* Create the new ReturnStmtNode structure */
	stmt = createReturnStmtNode(value);
	if (!stmt) goto parseReturnStmtNodeAbort;

	/* Create the new StmtNode structure */
	ret = createStmtNode(ST_RETURN, stmt);
	if (!ret) goto parseReturnStmtNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseReturnStmtNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteStmtNode(ret);
	else if (stmt) deleteReturnStmtNode(stmt);
	else {
		if (value) deleteExprNode(value);
	}
	return NULL;
}

/**
 * Parses tokens into a loop statement.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to a loop statement.
 *
 * \retval NULL Unable to parse.
 */
StmtNode *parseLoopStmtNode(Token ***tokenp)
{
	IdentifierNode *name1 = NULL;
	IdentifierNode *var = NULL;
	ExprNode *update = NULL;
	ExprNode *guard = NULL;
	BlockNode *body = NULL;
	FuncDefStmtNode *def = NULL;
	IdentifierNode *name2 = NULL;
	LoopStmtNode *stmt = NULL;
	ExprNodeList *args = NULL;
	char *id = NULL;

	/* For increment and decrement loops */
	IdentifierNode *varcopy = NULL;
	ExprNode *arg1 = NULL;
	ConstantNode *one = NULL;
	ExprNode *arg2 = NULL;
	OpExprNode *op = NULL;

	/* For function loops */
	IdentifierNode *scope = NULL;
	IdentifierNode *name = NULL;
	FuncCallExprNode *node = NULL;
	ExprNode *arg = NULL;

	/* For loop predicates */
	ExprNode *predarg = NULL;
	ExprNodeList *predargs = NULL;
	OpExprNode *predop = NULL;

	StmtNode *ret = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	debug("ST_LOOP");
#endif

	/* Remove the loop-start keyword from the token stream */
	status = acceptToken(&tokens, TT_IMINYR);
	if (!status) {
		parser_error_expected_token(TT_IMINYR, tokens);
		goto parseLoopStmtNodeAbort;
	}

	/* Parse the loop name */
	name1 = parseIdentifierNode(&tokens);
	if (!name1) goto parseLoopStmtNodeAbort;
	else if (name1->type != IT_DIRECT) {
		parser_error(PR_EXPECTED_LOOP_NAME, tokens);
		goto parseLoopStmtNodeAbort;
	}

	/* Check if an increment or decrement loop */
	if (peekToken(&tokens, TT_UPPIN) || peekToken(&tokens, TT_NERFIN)) {
		OpType type;

		/* Parse the increment token or decrement token */
		if (acceptToken(&tokens, TT_UPPIN)) {
			type = OP_ADD;
#ifdef DEBUG
			shiftout();
			debug("ET_OP (OP_ADD)");
#endif
		}
		else if (acceptToken(&tokens, TT_NERFIN)) {
			type = OP_SUB;
#ifdef DEBUG
			shiftout();
			debug("ET_OP (OP_SUB)");
#endif
		}
		else {
			parser_error_expected_either_token(TT_UPPIN, TT_NERFIN, tokens);
			goto parseLoopStmtNodeAbort;
		}

		/* Parse the required syntax */
		if (!acceptToken(&tokens, TT_YR)) {
			parser_error_expected_token(TT_YR, tokens);
			goto parseLoopStmtNodeAbort;
		}

		/* Parse the variable to operate on */
		var = parseIdentifierNode(&tokens);
		if (!var) goto parseLoopStmtNodeAbort;
#ifdef DEBUG
		shiftout();
		debug("ET_CONSTANT (CT_INTEGER)");
		shiftin();
		shiftin();
#endif
		/* Make a copy of the variable for use as a function argument */
		id = malloc(sizeof(char) * (strlen(var->id) + 1));
		if (!id) goto parseLoopStmtNodeAbort;
		strcpy(id, var->id);
		varcopy = createIdentifierNode(IT_DIRECT, id, NULL, var->fname, var->line);
		if (!varcopy) goto parseLoopStmtNodeAbort;
		id = NULL;

		/* Package the variable into an identifier expression */
		arg1 = createExprNode(ET_IDENTIFIER, varcopy);
		if (!arg1) goto parseLoopStmtNodeAbort;

		/* Create a constant integer "1" */
		one = createIntegerConstantNode(1);
		if (!one) goto parseLoopStmtNodeAbort;

		/* Package the constant into an expression */
		arg2 = createExprNode(ET_CONSTANT, one);
		if (!arg2) goto parseLoopStmtNodeAbort;

		/* Create a list of arguments */
		args = createExprNodeList();
		if (!args) goto parseLoopStmtNodeAbort;

		/* Add the packaged arguments to the argument list */
		status = addExprNode(args, arg1);
		if (!status) goto parseLoopStmtNodeAbort;
		arg1 = NULL;
		status = addExprNode(args, arg2);
		if (!status) goto parseLoopStmtNodeAbort;
		arg2 = NULL;

		/* Package the arguments and operation type in an expression */
		op = createOpExprNode(type, args);
		if (!op) goto parseLoopStmtNodeAbort;

		/* Create the update expression */
		update = createExprNode(ET_OP, op);
		if (!update) goto parseLoopStmtNodeAbort;
	}
	/* Check if a function loop */
	else if (nextToken(&tokens, TT_IZ)) {
		IdentifierNode *temp = NULL;
#ifdef DEBUG
		debug("ET_FUNCCALL");
#endif
		/* Parse the function scope */
		scope = parseIdentifierNode(&tokens);
		if (!scope) goto parseLoopStmtNodeAbort;

		/* Parse the function indicator */
		status = acceptToken(&tokens, TT_IZ);
		if (!status) {
			parser_error_expected_token(TT_IZ, tokens);
			goto parseLoopStmtNodeAbort;
		}

		/* Parse the function name */
		name = parseIdentifierNode(&tokens);
		if (!name) goto parseLoopStmtNodeAbort;

		/* Create a list of arguments */
		args = createExprNodeList();
		if (!args) goto parseLoopStmtNodeAbort;

		/* Check for unary function */
		status = acceptToken(&tokens, TT_YR);
		if (!status) {
			parser_error(PR_EXPECTED_UNARY_FUNCTION, tokens);
			goto parseLoopStmtNodeAbort;
		}

		/* Parse the unary function's single argument */
		arg = parseExprNode(&tokens);
		if (!arg) goto parseLoopStmtNodeAbort;

		/* Make sure the argument is an identifier */
		if (arg->type != ET_IDENTIFIER) {
			parser_error(PR_EXPECTED_IDENTIFIER, tokens);
			goto parseLoopStmtNodeAbort;
		}

		/* Add the argument to the argument list */
		status = addExprNode(args, arg);
		if (!status) goto parseLoopStmtNodeAbort;
		/* (Save a pointer to its expression for use, below) */
		temp = (IdentifierNode *)(arg->expr);
		arg = NULL;

		/* Copy the identifier to make it the loop variable */
		id = malloc(sizeof(char) * (strlen(temp->id) + 1));
		if (!id) goto parseLoopStmtNodeAbort;
		strcpy(id, temp->id);
		var = createIdentifierNode(IT_DIRECT, id, NULL, temp->fname, temp->line);
		if (!var) goto parseLoopStmtNodeAbort;
		id = NULL;

		/* Check for unary function */
		status = acceptToken(&tokens, TT_MKAY);
		if (!status) {
			parser_error_expected_token(TT_MKAY, tokens);
			goto parseLoopStmtNodeAbort;
		}

		/* Create a function call expression */
		node = createFuncCallExprNode(scope, name, args);
		if (!node) goto parseLoopStmtNodeAbort;

		/* Package the function call in an expression */
		update = createExprNode(ET_FUNCCALL, node);
		if (!update) goto parseLoopStmtNodeAbort;
	}

	/* If there is an update, parse any predicates */
	if (update) {
		/* Check for a while token */
		if (acceptToken(&tokens, TT_WILE)) {
			/* Parse the while predicate */
			guard = parseExprNode(&tokens);
			if (!guard) goto parseLoopStmtNodeAbort;
		}
		/* Check for an until token */
		else if (acceptToken(&tokens, TT_TIL)) {
#ifdef DEBUG
			shiftout();
			debug("ET_OP (OP_NOT)");
#endif
			/* Parse the until predicate */
			predarg = parseExprNode(&tokens);
			if (!predarg) goto parseLoopStmtNodeAbort;

			/* Create a list for predicate arguments */
			predargs = createExprNodeList();
			if (!predargs) goto parseLoopStmtNodeAbort;

			/* Add the until predicate to the list */
			status = addExprNode(predargs, predarg);
			if (!status) goto parseLoopStmtNodeAbort;
			predarg = NULL;
#ifdef DEBUG
			shiftin();
#endif
			/* Create a NOT operation with the predicate */
			predop = createOpExprNode(OP_NOT, predargs);
			if (!predop) goto parseLoopStmtNodeAbort;

			/* Package the NOT operation in an expression */
			guard = createExprNode(ET_OP, predop);
			if (!guard) goto parseLoopStmtNodeAbort;
		}
	}

	/* All of the above should be on its own line */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_EXPRESSION, tokens);
		goto parseLoopStmtNodeAbort;
	}

	/* Parse the body of the loop */
	body = parseBlockNode(&tokens);
	if (!body) goto parseLoopStmtNodeAbort;

	/* Parse the end-loop keywords */
	status = acceptToken(&tokens, TT_IMOUTTAYR);
	if (!status) {
		parser_error_expected_token(TT_IMOUTTAYR, tokens);
		goto parseLoopStmtNodeAbort;
	}

	/* Parse the end-of-loop name */
	name2 = parseIdentifierNode(&tokens);
	if (!name2) goto parseLoopStmtNodeAbort;
	else if (name2->type != IT_DIRECT) {
		parser_error(PR_EXPECTED_LOOP_NAME, tokens);
		goto parseLoopStmtNodeAbort;
	}

	/* Make sure the beginning-of-loop and end-of-loop names match */
	if (strcmp((char *)(name1->id), (char *)(name2->id))) {
		parser_error(PR_EXPECTED_MATCHING_LOOP_NAME, tokens);
		goto parseLoopStmtNodeAbort;
	}

	/* We no longer need the end-of-loop name */
	deleteIdentifierNode(name2);

	/* The end-of-loop structure should appear on its own line */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_EXPRESSION, tokens);
		goto parseLoopStmtNodeAbort;
	}

	/* Create the new LoopStmtNode structure */
	stmt = createLoopStmtNode(name1, var, guard, update, body);
	if (!stmt) goto parseLoopStmtNodeAbort;

	/* Create the new StmtNode structure */
	ret = createStmtNode(ST_LOOP, stmt);
	if (!ret) goto parseLoopStmtNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseLoopStmtNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteStmtNode(ret);
	else if (stmt) deleteLoopStmtNode(stmt);
	else {
		if (name2) deleteIdentifierNode(name2);
		if (def) deleteFuncDefStmtNode(def);
		if (body) deleteBlockNode(body);
		if (guard) deleteExprNode(guard);
		if (update) deleteExprNode(update);
		if (var) deleteIdentifierNode(var);
		if (name1) deleteIdentifierNode(name1);
		if (id) free(id);

		/* For increment and decrement loops */
		if (op) deleteOpExprNode(op);
		if (args) deleteExprNodeList(args);
		if (arg2) deleteExprNode(arg2);
		if (one) deleteConstantNode(one);
		if (arg1) deleteExprNode(arg1);
		if (varcopy) deleteIdentifierNode(varcopy);

		/* For function loops */
		if (arg) deleteExprNode(arg);
		if (node) deleteFuncCallExprNode(node);
		if (name) deleteIdentifierNode(name);
		if (scope) deleteIdentifierNode(scope);

		/* For loop predicates */
		if (predarg) deleteExprNode(predarg);
		if (predargs) deleteExprNodeList(predargs);
		if (predop) deleteOpExprNode(predop);
	}
	return NULL;
}

/**
 * Parses tokens into a deallocation statement.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to a deallocation statement.
 *
 * \retval NULL Unable to parse.
 */
StmtNode *parseDeallocationStmtNode(Token ***tokenp)
{
	IdentifierNode *target = NULL;
	DeallocationStmtNode *stmt = NULL;
	StmtNode *ret = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	debug("ST_DEALLOCATION");
#endif

	/* Parse the variable to deallocate */
	target = parseIdentifierNode(&tokens);
	if (!target) goto parseDeallocationStmtNodeAbort;

	/* Parse the deallocation token */
	status = acceptToken(&tokens, TT_RNOOB);
	if (!status) {
		parser_error_expected_token(TT_RNOOB, tokens);
		goto parseDeallocationStmtNodeAbort;
	}

	/* The deallocation statement must reside on its own line */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_STATEMENT, tokens);
		goto parseDeallocationStmtNodeAbort;
	}

	/* Create the new DeallocationStmtNode structure */
	stmt = createDeallocationStmtNode(target);
	if (!stmt) goto parseDeallocationStmtNodeAbort;

	/* Create the new StmtNode structure */
	ret = createStmtNode(ST_DEALLOCATION, stmt);
	if (!ret) goto parseDeallocationStmtNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseDeallocationStmtNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteStmtNode(ret);
	else if (stmt) deleteDeallocationStmtNode(stmt);
	else {
		if (target) deleteIdentifierNode(target);
	}

	return NULL;
}

/**
 * Parses tokens into a function definition statement.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to a function definition statement.
 *
 * \retval NULL Unable to parse.
 */
StmtNode *parseFuncDefStmtNode(Token ***tokenp)
{
	IdentifierNode *scope = NULL;
	IdentifierNode *name = NULL;
	IdentifierNodeList *args = NULL;
	IdentifierNode *arg = NULL;
	BlockNode *body = NULL;
	FuncDefStmtNode *stmt = NULL;
	StmtNode *ret = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	debug("ST_FUNCDEF");
#endif

	/* Parse the function definition token */
	status = acceptToken(&tokens, TT_HOWIZ);
	if (!status) {
		parser_error_expected_token(TT_HOWIZ, tokens);
		goto parseFuncDefStmtNodeAbort;
	}

	/* Parse the scope to define the function in */
	scope = parseIdentifierNode(&tokens);
	if (!scope) goto parseFuncDefStmtNodeAbort;

	/* Parse the name of the function */
	name = parseIdentifierNode(&tokens);
	if (!name) goto parseFuncDefStmtNodeAbort;

	/* Create a list of arguments */
	args = createIdentifierNodeList();
	if (!args) goto parseFuncDefStmtNodeAbort;

	/* Parse the first argument indicator */
	if (acceptToken(&tokens, TT_YR)) {
		/* Parse the first argument name */
		arg = parseIdentifierNode(&tokens);
		if (!arg) goto parseFuncDefStmtNodeAbort;

		/* Add the first argument to the arguments list */
		status = addIdentifierNode(args, arg);
		if (!status) goto parseFuncDefStmtNodeAbort;
		arg = NULL;

		/* Continue parsing argument indicators */
		while (acceptToken(&tokens, TT_ANYR)) {
			/* Parse the argument */
			arg = parseIdentifierNode(&tokens);
			if (!arg) goto parseFuncDefStmtNodeAbort;

			/* Add the argument to the arguments list */
			status = addIdentifierNode(args, arg);
			if (!status) goto parseFuncDefStmtNodeAbort;
			arg = NULL;
		}
	}

	/* The function declaration should appear on its own line */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_STATEMENT, tokens);
		goto parseFuncDefStmtNodeAbort;
	}

	/* Parse the body of the function */
	body = parseBlockNode(&tokens);
	if (!body) goto parseFuncDefStmtNodeAbort;

	/* Parse the end-function token */
	status = acceptToken(&tokens, TT_IFUSAYSO);
	if (!status) {
		parser_error_expected_token(TT_IFUSAYSO, tokens);
		goto parseFuncDefStmtNodeAbort;
	}

	/* The end-function token should appear on its own line */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_STATEMENT, tokens);
		goto parseFuncDefStmtNodeAbort;
	}

	/* Create the new FuncDefStmtNode structure */
	stmt = createFuncDefStmtNode(scope, name, args, body);
	if (!stmt) goto parseFuncDefStmtNodeAbort;

	/* Create the new StmtNode structure */
	ret = createStmtNode(ST_FUNCDEF, stmt);
	if (!ret) goto parseFuncDefStmtNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseFuncDefStmtNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteStmtNode(ret);
	else if (stmt) deleteFuncDefStmtNode(stmt);
	else {
		if (body) deleteBlockNode(body);
		if (args) deleteIdentifierNodeList(args);
		if (arg) deleteIdentifierNode(arg);
		if (name) deleteIdentifierNode(name);
		if (scope) deleteIdentifierNode(scope);
	}

	return NULL;
}

/**
 * Parses tokens into an alternate array definition statement.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to an alternate array definition statement.
 *
 * \retval NULL Unable to parse.
 */
StmtNode *parseAltArrayDefStmtNode(Token ***tokenp)
{
	IdentifierNode *name = NULL;
	BlockNode *body = NULL;
	IdentifierNode *parent = NULL;
	AltArrayDefStmtNode *stmt = NULL;
	StmtNode *ret = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	debug("ST_ALTARRAYDEF");
#endif

	/* Parse the alternate array definition token */
	status = acceptToken(&tokens, TT_OHAIIM);
	if (!status) {
		parser_error_expected_token(TT_OHAIIM, tokens);
		goto parseAltArrayDefStmtNodeAbort;
	}

	/* Parse the array name */
	name = parseIdentifierNode(&tokens);
	if (!name) goto parseAltArrayDefStmtNodeAbort;

	/* Check for an optional array inheritance */
	if (acceptToken(&tokens, TT_IMLIEK)) {
		/* Parse the parent to inherit from */
		parent = parseIdentifierNode(&tokens);
		if (!parent) goto parseAltArrayDefStmtNodeAbort;
	}

	/* The alternate array definition token and name should appear on their
	 * own line */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_STATEMENT, tokens);
		goto parseAltArrayDefStmtNodeAbort;
	}

	/* Parse the array definition body */
	body = parseBlockNode(&tokens);
	if (!body) goto parseAltArrayDefStmtNodeAbort;

	/* The end-alternate array definition token should appear on its own
	 * line */
	status = acceptToken(&tokens, TT_KTHX);
	if (!status) {
		parser_error_expected_token(TT_KTHX, tokens);
		goto parseAltArrayDefStmtNodeAbort;
	}

	/* The end-function token should appear on its own line */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_STATEMENT, tokens);
		goto parseAltArrayDefStmtNodeAbort;
	}

	/* Create the new AltArrayDefStmtNode structure */
	stmt = createAltArrayDefStmtNode(name, body, parent);
	if (!stmt) goto parseAltArrayDefStmtNodeAbort;

	/* Create the new StmtNode structure */
	ret = createStmtNode(ST_ALTARRAYDEF, stmt);
	if (!ret) goto parseAltArrayDefStmtNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseAltArrayDefStmtNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteStmtNode(ret);
	else if (stmt) deleteAltArrayDefStmtNode(stmt);
	else {
		if (name) deleteIdentifierNode(name);
		if (body) deleteBlockNode(body);
	}

	return NULL;
}

/**
 * Parses tokens into a library import statement.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to a return statement.
 *
 * \retval NULL Unable to parse.
 */
StmtNode *parseImportStmtNode(Token ***tokenp)
{
	IdentifierNode *value = NULL;
	ImportStmtNode *stmt = NULL;
	StmtNode *ret = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	debug("ST_IMPORT");
#endif

	/* Remove the library import keyword from the token stream */
	status = acceptToken(&tokens, TT_CANHAS);
	if (!status) {
		parser_error_expected_token(TT_CANHAS, tokens);
		goto parseImportStmtNodeAbort;
	}

	/* Parse the library name */
	value = parseIdentifierNode(&tokens);
	if (!value) goto parseImportStmtNodeAbort;

	/* Check for the question mark token (currently optional) */
	acceptToken(&tokens, TT_QUESTION);

	/* The library import statement must reside on its own line */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_EXPRESSION, tokens);
		goto parseImportStmtNodeAbort;
	}

	/* Create the new ImportStmtNode structure */
	stmt = createImportStmtNode(value);
	if (!stmt) goto parseImportStmtNodeAbort;

	/* Create the new StmtNode structure */
	ret = createStmtNode(ST_IMPORT, stmt);
	if (!ret) goto parseImportStmtNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return ret;

parseImportStmtNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (ret) deleteStmtNode(ret);
	else if (stmt) deleteImportStmtNode(stmt);
	else {
		if (value) deleteIdentifierNode(value);
	}
	return NULL;
}

/**
 * Parses tokens into a statement.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to a statement.
 *
 * \retval NULL Unable to parse.
 */
StmtNode *parseStmtNode(Token ***tokenp)
{
	StmtNode *ret = NULL;
	ExprNode *expr = NULL;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	shiftout();
#endif

	/* Parse context-sensitive expressions */
	if (peekToken(&tokens, TT_IDENTIFIER)
			|| peekToken(&tokens, TT_SRS)) {
		IdentifierNode *id = NULL;

		/* Remove the identifier from the token stream */
		id = parseIdentifierNode(&tokens);
		if (!id) return NULL;

		/* We do not need to hold onto it */
		deleteIdentifierNode(id);

		/* Casting */
		if (peekToken(&tokens, TT_ISNOWA)) {
			ret = parseCastStmtNode(tokenp);
		}
		/* Assignment */
		else if (peekToken(&tokens, TT_R)) {
			ret = parseAssignmentStmtNode(tokenp);
		}
		/* Variable declaration */
		else if (peekToken(&tokens, TT_HASA)) {
			ret = parseDeclarationStmtNode(tokenp);
		}
		/* Deallocation */
		else if (peekToken(&tokens, TT_RNOOB)) {
			ret = parseDeallocationStmtNode(tokenp);
		}
		/* Bare identifier expression */
		else {
			/* Reset state and continue parsing */
			tokens = *tokenp;

#ifdef DEBUG
			debug("ST_EXPR");
#endif

			/* Parse the expression */
			expr = parseExprNode(&tokens);
			if (!expr) return NULL;

			/* The expression should appear on its own line */
			if (!acceptToken(&tokens, TT_NEWLINE)) {
				parser_error(PR_EXPECTED_END_OF_EXPRESSION, tokens);
				deleteExprNode(expr);
				return NULL;
			}

			/* Create the new StmtNode structure */
			ret = createStmtNode(ST_EXPR, expr);
			if (!ret) {
				deleteExprNode(expr);
				return NULL;
			}

			/* Since we're successful, update the token stream */
			*tokenp = tokens;
		}
	}
	/* Print */
	else if (peekToken(&tokens, TT_VISIBLE)) {
		ret = parsePrintStmtNode(tokenp);
	}
	/* Input */
	else if (peekToken(&tokens, TT_GIMMEH)) {
		ret = parseInputStmtNode(tokenp);
	}
	/* If/then/else */
	else if (peekToken(&tokens, TT_ORLY)) {
		ret = parseIfThenElseStmtNode(tokenp);
	}
	/* Switch */
	else if (peekToken(&tokens, TT_WTF)) {
		ret = parseSwitchStmtNode(tokenp);
	}
	/* Break */
	else if (peekToken(&tokens, TT_GTFO)) {
		ret = parseBreakStmtNode(tokenp);
	}
	/* Return */
	else if (peekToken(&tokens, TT_FOUNDYR)) {
		ret = parseReturnStmtNode(tokenp);
	}
	/* Loop */
	else if (peekToken(&tokens, TT_IMINYR)) {
		ret = parseLoopStmtNode(tokenp);
	}
	/* Function definition */
	else if (peekToken(&tokens, TT_HOWIZ)) {
		ret = parseFuncDefStmtNode(tokenp);
	}
	/* Alternate array definition */
	else if (peekToken(&tokens, TT_OHAIIM)) {
		ret = parseAltArrayDefStmtNode(tokenp);
	}
	/* Library import statement */
	else if (peekToken(&tokens, TT_CANHAS)) {
		ret = parseImportStmtNode(tokenp);
	}
	/* Bare expression */
	else if ((expr = parseExprNode(&tokens))) {
		int status;

#ifdef DEBUG
		debug("ST_EXPR");
#endif

		/* The expression should appear on its own line */
		status = acceptToken(&tokens, TT_NEWLINE);
		if (!status) {
			parser_error(PR_EXPECTED_END_OF_EXPRESSION, tokens);
			deleteExprNode(expr);
			return NULL;
		}

		/* Create the new StmtNode structure */
		ret = createStmtNode(ST_EXPR, expr);
		if (!ret) {
			deleteExprNode(expr);
			return NULL;
		}

		/* Since we're successful, update the token stream */
		*tokenp = tokens;
	}
	else {
		parser_error(PR_EXPECTED_STATEMENT, tokens);
	}

#ifdef DEBUG
	shiftin();
#endif

	return ret;
}

/**
 * Parses tokens into a code block.
 *
 * \param [in] tokenp The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to a code block.
 *
 * \retval NULL Unable to parse.
 */
BlockNode *parseBlockNode(Token ***tokenp)
{
	StmtNodeList *stmts = NULL;
	StmtNode *stmt = NULL;
	BlockNode *block = NULL;
	int status;

	/* Work from a copy of the token stream in case something goes wrong */
	Token **tokens = *tokenp;

#ifdef DEBUG
	shiftout();
	debug(">ET_BLOCK");
#endif

	/* Create a list of statements */
	stmts = createStmtNodeList();
	if (!stmts) goto parseBlockNodeAbort;
	/* Parse block until certain tokens are found */
	while (!peekToken(&tokens, TT_EOF)
			&& !peekToken(&tokens, TT_KTHXBYE)
			&& !peekToken(&tokens, TT_OIC)
			&& !peekToken(&tokens, TT_YARLY)
			&& !peekToken(&tokens, TT_NOWAI)
			&& !peekToken(&tokens, TT_MEBBE)
			&& !peekToken(&tokens, TT_OMG)
			&& !peekToken(&tokens, TT_OMGWTF)
			&& !peekToken(&tokens, TT_IMOUTTAYR)
			&& !peekToken(&tokens, TT_IFUSAYSO)
			&& !peekToken(&tokens, TT_KTHX)) {
		/* Parse the next statement */
		stmt = parseStmtNode(&tokens);
		if (!stmt) goto parseBlockNodeAbort;

		/* Add the statement to the list */
		status = addStmtNode(stmts, stmt);
		if (!status) goto parseBlockNodeAbort;
		stmt = NULL;
	}

#ifdef DEBUG
	debug("<ET_BLOCK");
	shiftin();
#endif

	/* Create the BlockNode structure */
	block = createBlockNode(stmts);
	if (!block) goto parseBlockNodeAbort;

	/* Since we're successful, update the token stream */
	*tokenp = tokens;

	return block;

parseBlockNodeAbort: /* Exception handling */

	/* Clean up any allocated structures */
	if (block) deleteBlockNode(block);
	else {
		if (stmt) deleteStmtNode(stmt);
		if (stmts) deleteStmtNodeList(stmts);
	}
	return NULL;
}

/**
 * Parses tokens into a main code block.
 *
 * \param [in] tokens The position in a token list to start parsing at.
 *
 * \post \a tokenp will point to the next unparsed token.
 *
 * \return A pointer to a main node block.
 *
 * \retval NULL Unable to parse.
 */
MainNode *parseMainNode(Token **tokens)
{
	BlockNode *block = NULL;
	MainNode *_main = NULL;
	int status;

	/* All programs must start with the HAI token */
	status = acceptToken(&tokens, TT_HAI);
	if (!status) {
		parser_error_expected_token(TT_HAI, tokens);
		goto parseMainNodeAbort;
	}

	/* Accept any version */
	tokens++;

#ifdef DEBUG
	debug("ET_MAINBLOCK");
#endif

	/* Make sure the header line ends with a newline */
	status = acceptToken(&tokens, TT_NEWLINE);
	if (!status) {
		parser_error(PR_EXPECTED_END_OF_STATEMENT, tokens);
		goto parseMainNodeAbort;
	}

	/* Parse the main block of code */
	block = parseBlockNode(&tokens);
	if (!block) goto parseMainNodeAbort;

	/* Make sure the program ends with KTHXBYE */
	status = acceptToken(&tokens, TT_KTHXBYE);
	if (!status) {
		parser_error_expected_token(TT_KTHXBYE, tokens);
		goto parseMainNodeAbort;
	}

	/* Create the MainBlockNode structure */
	_main = createMainNode(block);
	if (!_main) goto parseMainNodeAbort;

	return _main;

parseMainNodeAbort: /* In case something goes wrong... */

	/* Clean up any allocated structures */
	if (_main) deleteMainNode(_main);
	else if (block) deleteBlockNode(block);

	return NULL;
}