feat(tazjin/rlox): Implement equality operator

Change-Id: I5587a11646e228c5af4dc7ca6da026bb4a2592a6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2574
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI
This commit is contained in:
Vincent Ambo 2021-02-28 15:57:08 +02:00 committed by tazjin
parent 93c30b339c
commit c58fe2093e
4 changed files with 50 additions and 6 deletions

View file

@ -120,6 +120,14 @@ fn rule_for<T: Iterator<Item = Token>>(token: &TokenKind) -> ParseRule<T> {
ParseRule::new(Some(Compiler::unary), None, Precedence::None)
}
TokenKind::BangEqual => {
ParseRule::new(None, Some(Compiler::binary), Precedence::Equality)
}
TokenKind::EqualEqual => {
ParseRule::new(None, Some(Compiler::binary), Precedence::Equality)
}
_ => ParseRule::new(None, None, Precedence::None),
}
}
@ -194,6 +202,14 @@ impl<T: Iterator<Item = Token>> Compiler<T> {
TokenKind::Plus => self.emit_op(OpCode::OpAdd),
TokenKind::Star => self.emit_op(OpCode::OpMultiply),
TokenKind::Slash => self.emit_op(OpCode::OpDivide),
TokenKind::BangEqual => {
self.emit_op(OpCode::OpEqual);
self.emit_op(OpCode::OpNot);
}
TokenKind::EqualEqual => self.emit_op(OpCode::OpEqual),
_ => unreachable!("only called for binary operator tokens"),
}

View file

@ -11,8 +11,9 @@ pub enum OpCode {
/// Return from the current function.
OpReturn,
// Boolean operators
// Boolean & comparison operators
OpNot,
OpEqual,
/// Unary negation
OpNegate,

View file

@ -14,6 +14,10 @@ fn expect_num(code: &str, value: f64) {
expect(code, Value::Number(value))
}
fn expect_bool(code: &str, value: bool) {
expect(code, Value::Bool(value))
}
#[test]
fn numbers() {
expect_num("1", 1.0);
@ -61,9 +65,26 @@ fn trivial_literals() {
#[test]
fn negation() {
expect("!true", Value::Bool(false));
expect("!false", Value::Bool(true));
expect("!nil", Value::Bool(true));
expect("!13.5", Value::Bool(false));
expect("!-42", Value::Bool(false));
expect_bool("!true", false);
expect_bool("!false", true);
expect_bool("!nil", true);
expect_bool("!13.5", false);
expect_bool("!-42", false);
}
#[test]
fn equality() {
expect_bool("42 == 42", true);
expect_bool("42 != 42", false);
expect_bool("42 == 42.0", true);
expect_bool("true == true", true);
expect_bool("true == false", false);
expect_bool("true == !false", true);
expect_bool("true != true", false);
expect_bool("true != false", true);
expect_bool("42 == false", false);
expect_bool("42 == true", false);
expect_bool("!42 == !true", true);
}

View file

@ -85,6 +85,12 @@ impl VM {
self.push(Value::Bool(v.is_falsey()));
}
OpCode::OpEqual => {
let b = self.pop();
let a = self.pop();
self.push(Value::Bool(a == b));
}
OpCode::OpNegate => {
let v = self.pop();
with_type!(