Ben / Nujel

/*
 * This file is a part of Nujel, licensed under the MIT License.
 */
#include "tree.h"

#include "list.h"
#include "../allocation/garbage-collection.h"
#include "../allocation/roots.h"
#include "../type/symbol.h"
#include "../type/val.h"

#ifndef COSMOPOLITAN_H_
	#include <stdlib.h>
#endif

lTree    lTreeList[TRE_MAX];
uint     lTreeActive = 0;
uint     lTreeMax    = 0;
lTree   *lTreeFFree  = NULL;

void lTreeInit(){
	lTreeActive  = 0;
	lTreeMax     = 0;
}

lTree *lTreeAlloc(){
	lTree *ret;
	if(lTreeFFree == NULL){
		if(lTreeMax >= TRE_MAX-1){
			lGarbageCollect();
			if(lTreeFFree == NULL){
				lPrintError("lTree OOM\n");
				exit(1);
			}else{
				ret       = lTreeFFree;
				lTreeFFree = ret->nextFree;
			}
		}else{
			ret = &lTreeList[lTreeMax++];
		}
	}else{
		ret       = lTreeFFree;
		lTreeFFree = ret->nextFree;
	}
	lTreeActive++;
	*ret = (lTree){0};
	return ret;
}

lTree *lTreeNew(const lSymbol *s, lVal *v){
	lTree *ret = lTreeAlloc();
	ret->key = s;
	ret->value = v;
	return ret;
}

void lTreeFree(lTree *t){
	if(t == NULL){return;}
	lTreeActive--;
	t->nextFree = lTreeFFree;
	lTreeFFree = t;
}

void lTreeSet(lTree *t, const lSymbol *s, lVal *v, bool *found){
	if(t == NULL){
		return;
	}else if(s == t->key){
		t->value = v;
		if(found){*found = true;}
	}else if(s > t->key){
		lTreeSet(t->right,s,v,found);
	}else{
		lTreeSet(t->left,s,v,found);
	}
}

lTree *lTreeInsert(lTree *t, const lSymbol *s, lVal *v){
	if(t == NULL){
		return lTreeNew(s,v);
	}else if(t->key == s){
		t->value = v;
		return t;
	}else if(s > t->key){
		t->right = lTreeInsert(t->right,s,v);
	}else {
		t->left = lTreeInsert(t->left,s,v);
	}
	return t;
}

lVal *lTreeGet(const lTree *t, const lSymbol *s, bool *found){
	const lTree *c = t;
	while(c != NULL){
		if(c->key == NULL){break;}
		if(s == c->key){
			if(found != NULL){*found = true;}
			return c->value;
		}
		c = s > c->key ? c->right : c->left;
	}
	if(found != NULL){*found = false;}
	return NULL;
}

bool lTreeHas(const lTree *t, const lSymbol *s, lVal **value){
	const lTree *c = t;
	while(c != NULL){
		if(c->key == NULL){break;}
		if(s == c->key){
			if(value != NULL){*value = c->value;}
			return true;
		}
		c = s > c->key ? c->right : c->left;
	}
	if(value != NULL){*value = NULL;}
	return false;
}

lVal *lTreeAddToList(const lTree *t, lVal *list){
	if(t == NULL){return list;}
	if(list != NULL){lRootsValPush(list);}
	lVal *l = lRootsValPush(lCons(NULL,NULL));
	l->vList.cdr = lCons(NULL,lTreeAddToList(t->right,list));
	l->vList.cdr->vList.car = t->value;
	l->vList.car = lValSymS(t->key);
	if(list != NULL){lRootsValPop();}
	lRootsValPop();
	return lTreeAddToList(t->left,l);
}

lVal *lTreeAddKeysToList(const lTree *t, lVal *list){
	if((t == NULL) || (t->key == NULL)){return list;}

	lRootsValPush(list);
	list = lTreeAddKeysToList(t->right,list);

	lVal *sym = lRootsValPush(lValSymS(t->key));
	list = lCons(sym,list);
	lRootsValPop();
	lRootsValPop();

	return lTreeAddKeysToList(t->left,list);
}

lVal *lTreeAddValuesToList(const lTree *t, lVal *list){
	if(t == NULL){return list;}
	list = lTreeAddValuesToList(t->right,list);

	if(list != NULL){lRootsValPush(list);}
	lVal *l = lCons(t->value,list);
	if(list != NULL){lRootsValPop();}

	return lTreeAddValuesToList(t->left,l);
}

lVal *lTreeToList(const lTree *t){
	return lTreeAddToList(t,NULL);
}

lVal *lTreeKeysToList(const lTree *t){
	return lTreeAddKeysToList(t,NULL);
}

lVal *lTreeValuesToList(const lTree *t){
	return lTreeAddValuesToList(t,NULL);
}

uint lTreeSize(const lTree *t){
	return t == NULL ? 0 : (t->key ? 1 : 0) + lTreeSize(t->left) + lTreeSize(t->right);
}