// Copyright (c) 2019 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
module ast

import (
	compiler2.token
)


struct Foo {}

// pub type Expr = Foo | IfExpr | BinaryExpr | IntegerExpr
pub type Expr = Foo | IfExpr | BinaryExpr | ScalarExpr | UnaryExpr

// pub struct IntegerExpr {
// pub:
// 	val int
// }

/*
pub enum Expr {
	Binary(BinaryExpr)
	If(IfExpr)
	Integer(IntegerExpr)
}
*/

pub struct Stmt {
	pos int
	//end int
}

// A single identifier
struct Ident {
	token token.Token
	value string
}

pub struct BinaryExpr {
pub:
	token token.Token
	//op    BinaryOp
	op    token.Token
	left  Expr
	right Expr
}

pub struct ScalarExpr {
pub:
	token token.Token
	// op    BinaryOp
	// op    token.Token
	typ   token.Token
	val   string
	left  Expr
}

pub struct UnaryExpr {
pub:
	// token token.Token
	//op    BinaryOp
	op    token.Token
	left  Expr
}

struct IfExpr {
	token token.Token
	cond  Expr
	body  []Stmt
	else_ []Stmt
}

struct ReturnStmt {
	token   token.Token // or pos
	results []Expr
}

// string representaiton of expr
pub fn (x Expr) str() string {
	match x {
		BinaryExpr {
			return '(${it.left.str()}$it.op.str()${it.right.str()})'
		}
		ScalarExpr {
			return '${it.left.str()}$it.val'
		}
		UnaryExpr {
			return '${it.left.str()}$it.op.str()'
		}
		else { return '' }
	}
}

// enum BinaryOp {
// 	sum
// 	difference
// 	product
// 	quotient
// 	remainder
// 	bitwise_and
// 	bitwise_or
// 	bitwise_xor
// 	left_shift
// 	right_shift

// 	equality
// 	inequality
// 	less_than
// 	less_than_or_equal
// 	more_than
// 	more_than_or_equal

// 	in_check

// 	//These are suffixed with `bool` to prevent conflict with the keyword `or`
// 	and_bool
// 	or_bool
// }