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fix(parser + lexer): interaction -- WIP

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This commit is contained in:
Matteo Flebus 2026-01-16 19:31:58 +01:00
parent 04529f858c
commit 10ce140e37
5 changed files with 99 additions and 48 deletions
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65
src/lexer/lexer.c
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@ -13,16 +13,40 @@
static char *end_last_token;
static ssize_t remaining_chars;
static bool at_beginning = true;
static struct token *last_token;
static struct token *current_token;
/* @brief: saves state for the next call the the lexer.
/* @brief: sets the current_token to [tok].
* this function is called by token_peek().
*/
static void update_current_token(struct token* tok)
{
current_token = tok;
}
/* @brief: frees the last token and sets it to [tok].
* Also sets current_token to NULL.
* this function is called by token_pop().
*
*/
static void save_state(char *stream, ssize_t i)
static void update_last_token(struct token* tok)
{
free_token(&last_token);
last_token = tok;
}
/* @brief: saves state for the next call to the the lexer.
* this function is called by token_pop().
*
*/
static void save_state(char *stream, ssize_t i, struct token *tok)
{
remaining_chars -= i;
end_last_token = stream + i;
at_beginning = false;
return;
update_last_token(tok);
}
/* @return: true if a special character from the grammar was found,
@ -67,7 +91,7 @@ static void set_token_spechar(struct token *tok, char *begin, ssize_t size)
*/
static void set_token_keyword(struct token *tok, char *begin, ssize_t size)
{
if (tok->type != TOKEN_NULL)
if (tok->type != TOKEN_NULL || size == 0)
return;
if (strncmp(begin, "if", size) == 0)
{
@ -101,7 +125,7 @@ static void set_token_keyword(struct token *tok, char *begin, ssize_t size)
*/
static void set_token_word(struct token *tok, char *begin, ssize_t size)
{
if (tok->type == TOKEN_NULL)
if (tok->type == TOKEN_NULL && size != 0)
{
tok->type = TOKEN_WORD;
tok->data = calloc(size + 1, sizeof(char));
@ -124,13 +148,14 @@ struct token *new_token(char *begin, ssize_t size)
return tok;
}
void free_token(struct token *tok)
void free_token(struct token **tok)
{
if (tok == NULL)
if (tok == NULL || *tok == NULL)
return;
if (tok->data != NULL)
free(tok->data);
free(tok);
if ((*tok)->data != NULL)
free((*tok)->data);
free(*tok);
*tok = NULL;
}
char *stream_init(void)
@ -156,6 +181,12 @@ char *stream_init(void)
struct token *peek_token(void)
{
// EOF looping mode
if (current_token != NULL && current_token->type == TOKEN_EOF)
{
return current_token;
}
char *stream = stream_init();
ssize_t i = 0;
@ -175,11 +206,18 @@ struct token *peek_token(void)
i++;
}
return new_token(stream, i);
struct token *tok = new_token(stream, i);
update_current_token(tok);
return tok;
}
struct token *pop_token(void)
{
if (last_token != NULL && last_token->type == TOKEN_EOF)
{
free_token(&last_token);
return NULL;
}
char *stream = stream_init();
ssize_t i = 0;
@ -199,7 +237,8 @@ struct token *pop_token(void)
i++;
}
save_state(stream, i);
struct token *tok = new_token(stream, i);
save_state(stream, i, tok);
return new_token(stream, i);
return tok;
}