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teliva
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snapshot: writing working? 

This is a complete mess. I want to abstract reading multiline strings
behind a function, but the lookahead requirements for that are quite
stringent. What's a reasonable abstraction here?
This commit is contained in:
Kartik K. Agaram 2021-12-11 09:37:23 -08:00
parent 052c5501ac
commit d5038fe514
3 changed files with 112 additions and 45 deletions
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41
src/lua.c
View File

@ -307,13 +307,15 @@ int load_definitions(lua_State *L) {
char *Image_name = NULL;
void load_tlv (lua_State *L, char *filename);
extern void load_tlv (lua_State *L, char *filename);
static int handle_image (lua_State *L, char **argv, int n) {
int status;
/* TODO: pass args in */
/* parse and load file contents (teliva_program array) */
Image_name = argv[n];
load_tlv(L, Image_name);
//? save_tlv(L, Image_name); // manual test; should always return identical result, modulo key order
//? exit(1);
status = load_definitions(L);
if (status != 0) return 0;
/* call main() */
@ -379,41 +381,12 @@ static void update_definition (lua_State *L, const char *name, char *new_content
}
static void save_image (lua_State *L) {
lua_getglobal(L, "teliva_program");
int history_array = lua_gettop(L);
int history_array_size = luaL_getn(L, history_array);
FILE *out = fopen(Image_name, "w");
fprintf(out, "teliva_program = {\n");
for (int i = 1; i <= history_array_size; ++i) {
lua_rawgeti(L, history_array, i);
int table = lua_gettop(L);
fprintf(out, " {\n");
for (lua_pushnil(L); lua_next(L, table) != 0; lua_pop(L, 1)) {
const char* key = lua_tostring(L, -2);
if (strcmp(key, "__teliva_undo") == 0) {
fprintf(out, " %s = %ld,\n", key, lua_tointeger(L, -1));
continue;
}
const char* value = lua_tostring(L, -1);
fprintf(out, " %s = [==[\n", key);
fprintf(out, "%s", value);
fprintf(out, "]==],\n");
}
fprintf(out, " },\n");
lua_pop(L, 1);
}
fprintf(out, "}\n");
fclose(out);
lua_pop(L, 1);
}
extern void save_tlv (lua_State *L, char *filename);
int load_editor_buffer_to_current_definition_in_image(lua_State *L) {
char new_contents[8192] = {0};
read_editor_buffer(new_contents);
update_definition(L, Current_definition, new_contents);
save_image(L);
save_tlv(L, Image_name);
/* reload binding */
return luaL_loadbuffer(L, new_contents, strlen(new_contents), Current_definition)
|| docall(L, 0, 1);
@ -651,12 +624,12 @@ void recent_changes_view (lua_State *L) {
/* TODO: go hotkey is misleading. edits will not be persisted until you return to recent changes */
edit(L, "teliva_editor_buffer");
load_note_from_editor_buffer(L, cursor);
save_image(L);
save_tlv(L, Image_name);
break;
case CTRL_U:
if (cursor < history_array_size) {
add_undo_event(L, cursor);
save_image(L);
save_tlv(L, Image_name);
}
break;
}

104
src/tlv.c
View File

@ -7,22 +7,37 @@
#include "lauxlib.h"
/* If you encounter assertion failures in this file and _didn't_ manually edit
* it, lease report the .tlv file that caused them: http://akkartik.name/contact. */
* it, lease report the .tlv file that caused them: http://akkartik.name/contact.
*
* Manually edited files can have cryptic errors. Teliva's first priority is
* to be secure, so it requires a fairly rigid file format and errors out if
* things are even slightly amiss. */
void teliva_load_multiline_string(lua_State* L, FILE* in, char* line, int capacity) {
/* This code is surprisingly hairy. Estimate of buffer overflows: 2. */
static void teliva_load_multiline_string(lua_State* L, FILE* in, char* line, int capacity) {
luaL_Buffer b;
luaL_buffinit(L, &b);
int expected_indent = -1;
while (1) {
if (feof(in)) break;
char c = fgetc(in);
//? printf("^%d$\n", (int)c);
ungetc(c, in);
if (c != ' ') {
/* new definition; signal end to caller without reading a new line */
strcpy(line, "-\n");
break;
}
memset(line, '\0', capacity);
if (fgets(line, capacity, in) == NULL) break; /* eof */
//? printf("ml: %s", line);
int max = strlen(line);
assert(line[max-1] == '\n');
int indent = 0;
while (indent < max-1 && line[indent] == ' ')
++indent;
if (line[indent] != '>') break;
if (line[indent] != '>') break; /* new key/value pair in definition */
if (expected_indent == -1)
expected_indent = indent;
else
@ -35,7 +50,8 @@ void teliva_load_multiline_string(lua_State* L, FILE* in, char* line, int capaci
}
/* leave a single table on stack containing the next top-level definition from the file */
void teliva_load_definition(lua_State* L, FILE* in) {
static void teliva_load_definition(lua_State* L, FILE* in) {
//? printf("== new definition\n");
lua_newtable(L);
int def_idx = lua_gettop(L);
char line[1024] = {'\0'};
@ -49,6 +65,7 @@ void teliva_load_definition(lua_State* L, FILE* in) {
do {
assert(line[0] == '-' || line[0] == ' ');
assert(line[1] == ' ');
//? printf("l: %s", line);
/* key/value pair always indented at 0, never empty, unambiguously not a multiline string */
char key[512] = {'\0'};
char value[1024] = {'\0'};
@ -62,18 +79,33 @@ void teliva_load_definition(lua_State* L, FILE* in) {
assert(key[strlen(key)-1] == ':');
key[strlen(key)-1] = '\0';
lua_pushstring(L, key);
//? printf("value: %s$\n", value);
if (value[0] != '\0') {
//? printf("single-line\n");
lua_pushstring(L, value); /* value string on same line */
assert(fgets(line, 1024, in));
char c = fgetc(in);
ungetc(c, in);
if (c == '-') {
strcpy(line, "-\n");
}
else {
assert(fgets(line, 1024, in));
//? printf("new line: %s", line);
}
}
else {
//? printf("multi-line\n");
teliva_load_multiline_string(L, in, line, 1024); /* load from later lines */
//? printf("new line: %s", line);
}
//? printf("adding key: %s$\n", lua_tostring(L, -2));
//? printf("adding value: %s$\n", lua_tostring(L, -1));
lua_settable(L, def_idx);
} while (line[0] == ' ');
}
void load_tlv(lua_State* L, char* filename) {
endwin();
lua_newtable(L);
int history_array = lua_gettop(L);
FILE* in = fopen(filename, "r");
@ -85,3 +117,65 @@ void load_tlv(lua_State* L, char* filename) {
fclose(in);
lua_setglobal(L, "teliva_program");
}
static void emit_multiline_string(FILE* out, const char* value) {
fprintf(out, " >");
for (const char* curr = value; *curr != '\0'; ++curr) {
if (*curr == '\n' && *(curr+1) != '\0')
fprintf(out, "\n >");
else
fprintf(out, "%c", *curr);
}
}
void save_tlv(lua_State* L, char* filename) {
//? printf("SAVE\n");
lua_getglobal(L, "teliva_program");
int history_array = lua_gettop(L);
int history_array_size = luaL_getn(L, history_array);
FILE *out = fopen(filename, "w");
fprintf(out, "# .tlv file generated by https://github.com/akkartik/teliva\n");
fprintf(out, "# You may edit it if you are careful; however, you may see cryptic errors if you\n");
fprintf(out, "# violate Teliva's assumptions.\n");
fprintf(out, "#\n");
fprintf(out, "# .tlv files are representations of Teliva programs. Teliva programs consist of\n");
fprintf(out, "# sequences of definitions. Each definition is a table of key/value pairs. Keys\n");
fprintf(out, "# and values are both strings.\n");
fprintf(out, "#\n");
fprintf(out, "# Lines in .tlv files always follow exactly one of the following forms:\n");
fprintf(out, "# - comment lines at the top of the file starting with '#' at column 0\n");
fprintf(out, "# - beginnings of definitions starting with '- ' at column 0, followed by a\n");
fprintf(out, "# key/value pair\n");
fprintf(out, "# - key/value pairs consisting of ' ' at column 0, containing either a\n");
fprintf(out, "# spaceless value on the same line, or a multi-line value\n");
fprintf(out, "# - multiline values indented by more than 2 spaces, starting with a '>'\n");
fprintf(out, "#\n");
fprintf(out, "# If these constraints are violated, Teliva may unceremoniously crash. Please\n");
fprintf(out, "# report bugs at http://akkartik.name/contact\n");
for (int i = 1; i <= history_array_size; ++i) {
lua_rawgeti(L, history_array, i);
int table = lua_gettop(L);
int first = 1;
for (lua_pushnil(L); lua_next(L, table) != 0; lua_pop(L, 1)) {
if (first) fprintf(out, "- ");
else fprintf(out, " ");
first = 0;
const char* key = lua_tostring(L, -2);
if (strcmp(key, "__teliva_undo") == 0) {
fprintf(out, "%s: %ld\n", key, lua_tointeger(L, -1));
continue;
}
const char* value = lua_tostring(L, -1);
if (strchr(value, ' ') || strchr(value, '\n')) {
fprintf(out, "%s:\n", key);
emit_multiline_string(out, value);
}
else {
fprintf(out, "%s: %s\n", key, value);
}
}
lua_pop(L, 1);
}
fclose(out);
lua_pop(L, 1);
}

12
src/x.tlv
View File

@ -1,10 +1,10 @@
- __teliva_timestamp: original
- __teliva_timestamp: foo1
window:
>window = curses.stdscr()
- __teliva_timestamp: original
- __teliva_timestamp: foo2
n:
>n = 0
- __teliva_timestamp: original
- __teliva_timestamp: foo3
render:
>function render(window)
> window:clear()
@ -17,10 +17,10 @@
> curses.refresh()
>end
__teliva_note: foo
- __teliva_timestamp: original
- __teliva_timestamp: foo4
menu:
>menu = {Enter="increment"}
- __teliva_timestamp: original
- __teliva_timestamp: foo5
update:
>function update(window)
> local key = curses.getch()
@ -28,7 +28,7 @@
> n = n+1
> end
>end
- __teliva_timestamp: original
- __teliva_timestamp: foo6
main:
>function main()
> for i=1,7 do