feat(ltm): some more work on the parser

ltm
Jef Roosens 2023-12-15 10:01:46 +01:00 committed by Chewing_Bever
parent 95788f22e3
commit 0bc8fc8273
Signed by: Jef Roosens
GPG Key ID: B75D4F293C7052DB
4 changed files with 112 additions and 48 deletions

View File

@ -19,8 +19,8 @@
typedef enum ltm_err {
ltm_err_ok = 0,
ltm_invalid_template,
ltm_failed_alloc,
ltm_err_invalid_template,
ltm_err_failed_alloc,
} ltm_err;
#endif

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@ -25,6 +25,7 @@ ltm_err ltm_template_compile(ltm_template **out, const char *template);
* @param template char buffer containing the template
* @param len length of the char buffer
*/
ltm_err ltm_template_compile_n(ltm_template **out, const char *template, size_t len);
ltm_err ltm_template_compile_n(ltm_template **out, const char *template,
size_t len);
#endif

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@ -4,7 +4,8 @@
#include "ltm/template.h"
typedef enum ltm_placeholder_type {
ltm_placeholder_type_var = 0,
ltm_placeholder_type_invalid = 0,
ltm_placeholder_type_var,
ltm_placeholder_type_loop_start,
ltm_placeholder_type_loop_end,
} ltm_placeholder_type;
@ -15,7 +16,10 @@ typedef enum ltm_placeholder_type {
typedef struct ltm_placeholder {
const char *start;
const char *end;
const char *name;
struct {
const char *s;
size_t len;
} name;
ltm_placeholder_type type;
} ltm_placeholder;

View File

@ -1,3 +1,4 @@
#include <stdbool.h>
#include <string.h>
#include "ltm/common.h"
@ -8,7 +9,7 @@ ltm_err ltm_template_init(ltm_template **out) {
ltm_template *template = calloc(1, sizeof(ltm_template));
if (template == NULL) {
return ltm_failed_alloc;
return ltm_err_failed_alloc;
}
*out = template;
@ -16,7 +17,8 @@ ltm_err ltm_template_init(ltm_template **out) {
return ltm_err_ok;
}
ltm_err ltm_template_next_placeholder(ltm_placeholder *ph, const char *s, size_t len) {
bool ltm_template_next_placeholder(ltm_placeholder *ph, const char *s,
size_t len) {
ph->start = memchr(s, '{', len - 1);
if ((ph->start != NULL) && (ph->start[1] == '{')) {
@ -26,62 +28,119 @@ ltm_err ltm_template_next_placeholder(ltm_placeholder *ph, const char *s, size_t
// Non-terminated placeholders aren't valid
if ((ph->end == NULL) || (ph->end[1] != '}')) {
return ltm_invalid_template;
ph->type = ltm_placeholder_type_invalid;
return true;
}
} else {
ph->end = NULL;
// End should point to final character
ph->end++;
// Parse the words
ph->name.s = ph->start + 2;
while ((*ph->name.s == ' ') && (ph->name.s != ph->end - 1)) {
ph->name.s++;
}
// Placeholder is empty
if (ph->name.s == ph->end - 1) {
ph->type = ltm_placeholder_type_invalid;
return true;
}
const char *ident = ph->name.s;
while ((*ident != ' ') && (ident != ph->end - 1)) {
ident++;
}
ph->name.len = ident - ph->name.s;
while ((*ident == ' ') && (ident != ph->end - 1)) {
ident++;
}
if (ident == ph->end - 1) {
ph->type = ltm_placeholder_type_var;
} else {
// Further parse the identifier
const char *temp = ident;
while ((*temp != ' ') && (temp != ph->end - 1)) {
temp++;
}
size_t ident_len = temp - ident;
if (strncmp("loop", ident, ident_len) == 0) {
ph->type = ltm_placeholder_type_loop_start;
} else if (strncmp("end", ident, ident_len) == 0) {
ph->type = ltm_placeholder_type_loop_end;
} else {
ph->type = ltm_placeholder_type_invalid;
}
}
return true;
}
return ltm_err_ok;
return false;
}
ltm_err ltm_template_compile_n(ltm_template **out, const char *s, size_t len) {
ltm_template *template;
LTM_RES(ltm_template_init(&template));
const char *start, *end;
ltm_placeholder ph;
bool in_loop = false;
const char *loop_start = NULL;
size_t loop_depth = 0;
size_t cur_loop_depth = 0;
while (((start = memchr(s, '{', len - 1)) != NULL) && (start[1] == '{')) {
size_t new_len = len - (start - s);
// TODO to ensure the loops are balanced, we should count how many loop starts
// we have seen and only match a loop end if the number matches; this way, we
// can allow arbitrarily nested loops
// Non-terminated placeholders aren't valid
if (((end = memchr(start + 2, '}', new_len - 3)) == NULL) || (end[1] != '}')) {
return ltm_invalid_template;
}
// TODO actually parse placeholders
const char *word = start + 2;
while ((*word == ' ') && (word != end)) {
word++;
}
// The placeholder is empty
if (word == end) {
return ltm_invalid_template;
}
const char *word2 = word;
while ((*word2 != ' ') && (word2 != end)) {
word2++;
}
size_t word_len = word2 - word;
if (word2 != end) {
while ((*word2 == ' ') && (word2 != end)) {
word2++;
while (ltm_template_next_placeholder(&ph, s, len)) {
switch (ph.type) {
case ltm_placeholder_type_invalid:
return ltm_err_invalid_template;
case ltm_placeholder_type_var:
// TODO add var block
break;
case ltm_placeholder_type_loop_start:
if (!in_loop) {
loop_start = ph.end + 1;
in_loop = true;
loop_depth = cur_loop_depth;
}
cur_loop_depth++;
break;
case ltm_placeholder_type_loop_end:
cur_loop_depth--;
if (in_loop && (cur_loop_depth == loop_depth)) {
size_t loop_len = ph.end - loop_start;
// TODO recursive call to compile
in_loop = false;
}
// We encountered a loop end without a start
else {
return ltm_err_invalid_template;
}
break;
}
// Only one word, so it's a variable
if (word2 == end) {
// TODO register variable block
}
len -= ph.end + 1 - ph.start;
s = ph.end + 1;
}
len = len - (end + 2 - s);
s = end + 2;
// Unfinished loop
if (in_loop) {
return ltm_err_invalid_template;
}
return ltm_err_ok;