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/* utility_functions.c - List manipulation functions, element
* constructors, and macro definitions for leg markdown parser. */
#include "utility_functions.h"
#include "markdown_peg.h"
#include <string.h>
#include <assert.h>
/**********************************************************************
List manipulation functions
***********************************************************************/
/* cons - cons an element onto a list, returning pointer to new head */
element * cons(element *new, element *list) {
assert(new != NULL);
new->next = list;
return new;
}
/* reverse - reverse a list, returning pointer to new list */
element *reverse(element *list) {
element *new = NULL;
element *next = NULL;
while (list != NULL) {
next = list->next;
new = cons(list, new);
list = next;
}
return new;
}
/* concat_string_list - concatenates string contents of list of STR elements.
* Frees STR elements as they are added to the concatenation. */
GString *concat_string_list(element *list) {
GString *result;
element *next;
result = g_string_new("");
while (list != NULL) {
assert(list->key == STR);
assert(list->contents.str != NULL);
g_string_append(result, list->contents.str);
next = list->next;
free_element(list);
list = next;
}
return result;
}
/**********************************************************************
Global variables used in parsing
***********************************************************************/
char *charbuf = ""; /* Buffer of characters to be parsed. */
element *references = NULL; /* List of link references found. */
element *notes = NULL; /* List of footnotes found. */
element *parse_result; /* Results of parse. */
int syntax_extensions; /* Syntax extensions selected. */
/**********************************************************************
Auxiliary functions for parsing actions.
These make it easier to build up data structures (including lists)
in the parsing actions.
***********************************************************************/
/* mk_element - generic constructor for element */
element * mk_element(int key) {
element *result = malloc(sizeof(element));
result->key = key;
result->children = NULL;
result->next = NULL;
result->contents.str = NULL;
return result;
}
/* mk_str - constructor for STR element */
element * mk_str(char *string) {
element *result;
assert(string != NULL);
result = mk_element(STR);
result->contents.str = strdup(string);
return result;
}
/* mk_str_from_list - makes STR element by concatenating a
* reversed list of strings, adding optional extra newline */
element * mk_str_from_list(element *list, bool extra_newline) {
element *result;
GString *c = concat_string_list(reverse(list));
if (extra_newline)
g_string_append(c, "\n");
result = mk_element(STR);
result->contents.str = c->str;
g_string_free(c, false);
return result;
}
/* mk_list - makes new list with key 'key' and children the reverse of 'lst'.
* This is designed to be used with cons to build lists in a parser action.
* The reversing is necessary because cons adds to the head of a list. */
element * mk_list(int key, element *lst) {
element *result;
result = mk_element(key);
result->children = reverse(lst);
return result;
}
/* mk_link - constructor for LINK element */
element * mk_link(element *label, char *url, char *title) {
element *result;
result = mk_element(LINK);
result->contents.link = malloc(sizeof(link));
result->contents.link->label = label;
result->contents.link->url = strdup(url);
result->contents.link->title = strdup(title);
return result;
}
/* extension = returns true if extension is selected */
bool extension(int ext) {
return (syntax_extensions & ext);
}
/* match_inlines - returns true if inline lists match (case-insensitive...) */
bool match_inlines(element *l1, element *l2) {
while (l1 != NULL && l2 != NULL) {
if (l1->key != l2->key)
return false;
switch (l1->key) {
case SPACE:
case LINEBREAK:
case ELLIPSIS:
case EMDASH:
case ENDASH:
case APOSTROPHE:
break;
case CODE:
case STR:
case HTML:
if (strcasecmp(l1->contents.str, l2->contents.str) == 0)
break;
else
return false;
case EMPH:
case STRONG:
case LIST:
case SINGLEQUOTED:
case DOUBLEQUOTED:
if (match_inlines(l1->children, l2->children))
break;
else
return false;
case LINK:
case IMAGE:
return false; /* No links or images within links */
default:
fprintf(stderr, "match_inlines encountered unknown key = %d\n", l1->key);
exit(EXIT_FAILURE);
break;
}
l1 = l1->next;
l2 = l2->next;
}
return (l1 == NULL && l2 == NULL); /* return true if both lists exhausted */
}
/* find_reference - return true if link found in references matching label.
* 'link' is modified with the matching url and title. */
bool find_reference(link *result, element *label) {
element *cur = references; /* pointer to walk up list of references */
link *curitem;
while (cur != NULL) {
curitem = cur->contents.link;
if (match_inlines(label, curitem->label)) {
*result = *curitem;
return true;
}
else
cur = cur->next;
}
return false;
}
/* find_note - return true if note found in notes matching label.
if found, 'result' is set to point to matched note. */
bool find_note(element **result, char *label) {
element *cur = notes; /* pointer to walk up list of notes */
while (cur != NULL) {
if (strcmp(label, cur->contents.str) == 0) {
*result = cur;
return true;
}
else
cur = cur->next;
}
return false;
}
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