#include "rc.h"
#include "parse.h"

static Tree *nodes;

Tree*
maketree(void)
{
    Tree *node = emalloc(sizeof(*node));

    node->link = nodes;
    nodes = node;
    return node;
}

void
freeparsetree(void)
{
    Tree *t, *nt;
    for(t = nodes; t; t = nt) {
        nt = t->link;
        if(t->type == Tword && t->str)
            efree(t->str);
        efree(t);
    }
    nodes = nil;
}

Tree*
maketree1(int type, Tree *c0)
{
    return maketree2(type, c0, nil);
}

Tree*
maketree2(int type, Tree *c0, Tree *c1)
{
    return maketree3(type, c0, c1, nil);
}

Tree*
maketree3(int type, Tree *c0, Tree *c1, Tree *c2)
{
    Tree *node = maketree();

    node->type = type;
    node->child[0] = c0;
    node->child[1] = c1;
    node->child[2] = c2;

    return node;
}

Tree*
hangchild1(Tree *node, Tree *c, int i)
{
    node->child[i] = c;

    return node;
}

Tree*
hangchild2(Tree *node, Tree *c1, int i1, Tree *c2, int i2)
{
    node->child[i1] = c1;
    node->child[i2] = c2;

    return node;
}

Tree*
hangchild3(Tree *node, Tree *c0, Tree *c1, Tree *c2)
{
    node->child[0] = c0;
    node->child[1] = c1;
    node->child[2] = c2;

    return node;
}

Tree*
hangepilog(Tree *cmd, Tree *epi)
{
    Tree *p;
    if(!epi)
        return cmd;
    for(p = epi; p->child[1]; p = p->child[1])
        ;

    p->child[1] = cmd;
    return epi;
}

Tree*
token(int type, char *s)
{
    Tree *node = maketree();

    node->type = type;
    node->str = strdup(s);

    return node;
}

/*
Tree*
basic(Tree *node)
{
    return maketree1(Tbasic, node);
}
*/