Merge pull request #27 from 0x0dea/invisible

add INVISIBLE operator for writing to stderr

interpreter.c

@@ -3087,12 +3087,12 @@ ReturnObject *interpretPrintStmtNode(StmtNode *node,
 			deleteValueObject(use);
 			return NULL;
 		}
-		printf("%s", getString(use));
+		fprintf(stmt->file, "%s", getString(use));
 		deleteValueObject(val);
 		deleteValueObject(use);
 	}
 	if (!stmt->nonl)
-		printf("\n");
+		putc('\n', stmt->file);
 	return createReturnObject(RT_DEFAULT, NULL);
 }
 

parser.c

@@ -629,6 +629,8 @@ void deleteCastStmtNode(CastStmtNode *node)
  *
  * \param [in] args The expressions to print.
  *
+ * \param [in] file Where to print (\c stdout or \c stderr).
+ *
  * \param [in] nonl Whether an ending newline should be surpressed.
  *
  * \return A pointer to the print statement with the desired properties.
@@ -636,6 +638,7 @@ void deleteCastStmtNode(CastStmtNode *node)
  * \retval NULL Memory allocation failed.
  */
 PrintStmtNode *createPrintStmtNode(ExprNodeList *args,
+                                   FILE *file,
                                    int nonl)
 {
 	PrintStmtNode *p = malloc(sizeof(PrintStmtNode));
@@ -644,6 +647,7 @@ PrintStmtNode *createPrintStmtNode(ExprNodeList *args,
 		return NULL;
 	}
 	p->args = args;
+	p->file = file;
 	p->nonl = nonl;
 	return p;
 }
@@ -2477,6 +2481,7 @@ StmtNode *parsePrintStmtNode(Token ***tokenp)
 {
 	ExprNode *arg = NULL;
 	ExprNodeList *args = NULL;
+	FILE *file = stdout;
 	int nonl = 0;
 	PrintStmtNode *stmt = NULL;
 	StmtNode *ret = NULL;
@@ -2489,13 +2494,21 @@ StmtNode *parsePrintStmtNode(Token ***tokenp)
 	debug("ST_PRINT");
 #endif
 
-	/* Remove the print keyword from the token stream */
+	/**
+	 * Remove the print keyword from the token stream
+	 * A "quad-bool" is used to indicate whether we succeeded or failed to
+	 * accept either a \c TT_VISIBLE or \c TT_INVISIBLE token.
+	 */
 	status = acceptToken(&tokens, TT_VISIBLE);
-	if (!status) {
-		parser_error_expected_token(TT_VISIBLE, tokens);
+	if (!status) status = acceptToken(&tokens, TT_INVISIBLE) ? 2 : -1;
+	if (status < 1) {
+		parser_error_expected_token(TT_VISIBLE - status, tokens);
 		goto parsePrintStmtNodeAbort;
 	}
 
+	/* Use standard error if we accepted a \c TT_INVISIBLE above */
+	if (status == 2) file = stderr;
+
 	/* Parse the arguments to the print statement */
 	args = createExprNodeList();
 	if (!args) goto parsePrintStmtNodeAbort;
@@ -2515,7 +2528,7 @@ StmtNode *parsePrintStmtNode(Token ***tokenp)
 			&& !peekToken(&tokens, TT_BANG));
 
 	/* Check for the no-newline token */
-	if(acceptToken(&tokens, TT_BANG)) nonl = 1;
+	if (acceptToken(&tokens, TT_BANG)) nonl = 1;
 
 	/* Make sure the statement ends with a newline */
 	status = acceptToken(&tokens, TT_NEWLINE);
@@ -2525,7 +2538,7 @@ StmtNode *parsePrintStmtNode(Token ***tokenp)
 	}
 
 	/* Create the new PrintStmtNode structure */
-	stmt = createPrintStmtNode(args, nonl);
+	stmt = createPrintStmtNode(args, file, nonl);
 	if (!stmt) goto parsePrintStmtNodeAbort;
 
 	/* Create the new StmtNode structure */
@@ -3963,6 +3976,10 @@ StmtNode *parseStmtNode(Token ***tokenp)
 	else if (peekToken(&tokens, TT_VISIBLE)) {
 		ret = parsePrintStmtNode(tokenp);
 	}
+	/* Warn */
+	else if (peekToken(&tokens, TT_INVISIBLE)) {
+		ret = parsePrintStmtNode(tokenp);
+	}
 	/* Input */
 	else if (peekToken(&tokens, TT_GIMMEH)) {
 		ret = parseInputStmtNode(tokenp);

parser.h

@@ -70,6 +70,7 @@
  *
  * \par
  * PrintStmtNode ::= \c TT_VISIBLE ExprNodeList \c TT_BANG ? \c TT_NEWLINE
+ * | \c TT_INVISIBLE ExprNodeList \c TT_BANG ? \c TT_NEWLINE
  *
  * \par
  * InputStmtNode ::= \c TT_GIMMEH IdentifierNode \c TT_NEWLINE
@@ -395,6 +396,7 @@ typedef struct {
  */
 typedef struct {
 	ExprNodeList *args; /**< The expressions to print. */
+	FILE *file;         /**< Where to print (\c stdout or \c stderr). */
 	int nonl;           /**< Whether to print an ending newline. */
 } PrintStmtNode;
 
@@ -612,7 +614,7 @@ void deleteCastStmtNode(CastStmtNode *);
  * Functions for creating and deleting PrintStmtNodes.
  */
 /**@{*/
-PrintStmtNode *createPrintStmtNode(ExprNodeList *, int);
+PrintStmtNode *createPrintStmtNode(ExprNodeList *, FILE *, int);
 void deletePrintStmtNode(PrintStmtNode *);
 /**@}*/
 

tokenizer.h

@@ -76,6 +76,7 @@ typedef enum {
 	TT_A,           /**< Cast target separator. */
 	TT_ISNOWA,      /**< In-place cast. */
 	TT_VISIBLE,     /**< Print. */
+	TT_INVISIBLE,   /**< Print to standard error. */
 	TT_SMOOSH,      /**< String concatenation. */
 	TT_BANG,        /**< Exclamation point (!) */
 	TT_GIMMEH,      /**< Input. */
@@ -153,6 +154,7 @@ static const char *keywords[] = {
 	"A",           /* TT_A */
 	"IS NOW A",    /* TT_ISNOWA */
 	"VISIBLE",     /* TT_VISIBLE */
+	"INVISIBLE",   /* TT_INVISIBLE */
 	"SMOOSH",      /* TT_SMOOSH */
 	"!",           /* TT_BANG */
 	"GIMMEH",      /* TT_GIMMEH */