/*
 * Implementation of functions used to build the abstract syntax tree.
 */
 
#include "LuaSL_LSL_tree.h"
#include <stdlib.h>
 
/**
 * @brief Allocates space for expression
 * @return The expression or NULL if not enough memory
 */
static SExpression* allocateExpression()
{
        SExpression* b = malloc(sizeof *b);
 
        if( b == NULL ) return NULL;
 
        b->type = eVALUE;
        b->value = 0;
 
        b->left = NULL;
        b->right = NULL;
 
        return b;
}
 
SExpression* createNumber(int value)
{
        SExpression* b = allocateExpression();
 
        if( b == NULL ) return NULL;
 
        b->type = eVALUE;
        b->value = value;
 
        return b;
}
 
SExpression *createOperation( 
                        EOperationType type,
                        SExpression *left,
                        SExpression *right)
{
        SExpression* b = allocateExpression();
 
        if( b == NULL ) return NULL;
 
        b->type = type;
        b->left = left;
        b->right = right;
 
        return b;
}
 
void deleteExpression(SExpression *b)
{
        if (b == NULL) return;
 
        deleteExpression(b->left);
        deleteExpression(b->right);
 
        free(b);
}