#ifndef ABC_EXPR_H
#define ABC_EXPR_H

#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>

#include "ustr.h"

enum ExprKind
{
    EK_BINARY,
    // binary expression
    EK_ADD = EK_BINARY,
    EK_ASSIGN,
    EK_SUB,
    EK_MUL,
    EK_DIV,
    EK_POW,
    EK_BINARY_END,

    EK_UNARY = EK_BINARY_END,
    // unary expression
    EK_UNARY_MINUS = EK_UNARY,
    EK_UNARY_PLUS,
    EK_UNARY_END,

    EK_PRIMARY = EK_UNARY_END,
    // primary expression
    EK_UNSIGNED_LITERAL = EK_PRIMARY,
    EK_IDENTIFIER,
    EK_PRIMARY_END,
};

struct Expr;

// constructors
struct Expr *newUnsignedLiteralExpr(uint64_t uint);
struct Expr *newIdentifierExpr(const struct UStr *identifier);
struct Expr *newUnaryExpr(enum ExprKind kind, const struct Expr *unary);
struct Expr *newBinaryExpr(enum ExprKind kind, const struct Expr *left,
                           const struct Expr *right);

// destrcutor
void deleteExpr(const struct Expr *expr);

// methods
bool isLValueExpr(const struct Expr *expr);
double evalExpr(const struct Expr *expr);
void printExprTree(const struct Expr *expr, FILE *out);

#endif // ABC_EXPR_H