path: root/src/ast.c

#include <stdbool.h>
#include <stdio.h>
#include "buffer.h"
#include "ast.h"
#include "references.h"
#include "html/houdini.h"

// Free a node_block list and any children.
void cmark_free_blocks(cmark_node_block *e)
{
    cmark_node_block * next;
    while (e != NULL) {
        cmark_free_inlines(e->inline_content);
        strbuf_free(&e->string_content);
        if (e->tag == CMARK_BLOCK_FENCED_CODE) {
            strbuf_free(&e->as.code.info);
        } else if (e->tag == CMARK_BLOCK_DOCUMENT) {
            reference_map_free(e->as.document.refmap);
        }
        if (e->last_child) {
            // Splice children into list
            e->last_child->next = e->next;
            e->next = e->children;
        }
        next = e->next;
        free(e);
        e = next;
    }
}

// Utility function used by free_inlines
static void splice_into_list(cmark_node_inl* e, node_inl* children) {
    cmark_node_inl * tmp;
    if (children) {
        tmp = children;
        // Find last child
        while (tmp->next) {
            tmp = tmp->next;
        }
        // Splice children into list
        tmp->next = e->next;
        e->next = children;
    }
    return ;
}

// Free an inline list.  Avoid recursion to prevent stack overflows
// on deeply nested structures.
void cmark_free_inlines(cmark_node_inl* e)
{
    node_inl * next;

    while (e != NULL) {
        switch (e->tag){
        case CMARK_INL_STRING:
        case CMARK_INL_RAW_HTML:
        case CMARK_INL_CODE:
            cmark_chunk_free(&e->content.literal);
            break;
        case CMARK_INL_LINEBREAK:
        case CMARK_INL_SOFTBREAK:
            break;
        case CMARK_INL_LINK:
        case CMARK_INL_IMAGE:
            free(e->content.linkable.url);
            free(e->content.linkable.title);
            splice_into_list(e, e->content.linkable.label);
            break;
        case CMARK_INL_EMPH:
        case CMARK_INL_STRONG:
                splice_into_list(e, e->content.inlines);
            break;
        default:
                fprintf(stderr, "[WARN] (%s:%d) Unknown inline tag %d",
                __FILE__, __LINE__, e->tag);
            break;
        }
        next = e->next;
        free(e);
        e = next;
    }
}

inline cmark_node_inl *cmark_make_link(cmark_node_inl *label, unsigned char *url, unsigned char *title)
{
    cmark_node_inl* e = calloc(1, sizeof(*e));
    if(e != NULL) {
        e->tag = CMARK_INL_LINK;
        e->content.linkable.label = label;
        e->content.linkable.url   = url;
        e->content.linkable.title = title;
        e->next = NULL;
    }
    return e;
}

unsigned char *clean_autolink(chunk *url, int is_email)
{
    strbuf buf = GH_BUF_INIT;

    chunk_trim(url);

    if (url->len == 0)
        return NULL;

    if (is_email)
        strbuf_puts(&buf, "mailto:");

    houdini_unescape_html_f(&buf, url->data, url->len);
    return strbuf_detach(&buf);
}

cmark_node_inl* cmark_make_autolink(cmark_node_inl* label, chunk url, int is_email)
{
    return cmark_make_link(label, clean_autolink(&url, is_email), NULL);
}

inline cmark_node_inl* cmark_make_inlines(int t, cmark_node_inl* contents)
{
    cmark_node_inl * e = calloc(1, sizeof(*e));
    if(e != NULL) {
        e->tag = t;
        e->content.inlines = contents;
        e->next = NULL;
    }
    return e;
}

// Create an inline with a literal string value.
inline cmark_node_inl* cmark_make_literal(int t, cmark_chunk s)
{
    cmark_node_inl * e = calloc(1, sizeof(*e));
    if(e != NULL) {
        e->tag = t;
        e->content.literal = s;
        e->next = NULL;
    }
    return e;
}

// Create an inline with no value.
inline cmark_node_inl* cmark_make_simple(int t)
{
    cmark_node_inl* e = calloc(1, sizeof(*e));
    if(e != NULL) {
        e->tag = t;
        e->next = NULL;
    }
    return e;
}

// Append inline list b to the end of inline list a.
// Return pointer to head of new list.
inline cmark_node_inl* cmark_append_inlines(cmark_node_inl* a, cmark_node_inl* b)
{
    if (a == NULL) {  // NULL acts like an empty list
        return b;
    }
    cmark_node_inl* cur = a;
    while (cur->next) {
        cur = cur->next;
    }
    cur->next = b;
    return a;
}