//
// definitions.c - Code for defining named pattern rules
//

#include <err.h>
#include <stdlib.h>
#include <string.h>

#include "definitions.h"
#include "pattern.h"
#include "utils.h"

static size_t next_id = 0;

//
// Return a new list of definitions with one added to the front
//
def_t *with_def(def_t *defs, size_t namelen, const char *name, pat_t *pat)
{
    def_t *def = new(def_t);
    def->id = next_id++;
    def->next = defs;
    def->namelen = namelen;
    def->name = name;
    def->pat = pat;
    return def;
}

//
// Look up a backreference or grammar definition by name
//
def_t *lookup(def_t *defs, size_t namelen, const char *name)
{
    for ( ; defs; defs = defs->next) {
        if (namelen == defs->namelen && strncmp(defs->name, name, namelen) == 0)
            return defs;
    }
    return NULL;
}

//
// Free all the given definitions up till (but not including) `stop`
//
def_t *free_defs(def_t *defs, def_t *stop)
{
    while (defs != stop && defs != NULL) {
        def_t *next = defs->next;
        defs->next = NULL;
        free(defs);
        defs = next;
    }
    return defs;
}

// vim: ts=4 sw=0 et cino=L2,l1,(0,W4,m1,\:0