c/crafting-interpreters
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[rlox] Make nil falsey + add equal and comparisons

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This commit is contained in:
ctsk
2023-10-09 13:47:46 +02:00
parent 8ea397881c
commit 90e70c4cd2
3 changed files with 67 additions and 42 deletions
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49
rlox/src/lc.rs
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@@ -286,22 +286,6 @@ enum Precedence {
Primary,
}
type ParseInfo = (Associativity, Precedence, Op, Option<Op>);
fn get_info(ttype: TokenType) -> ParseInfo {
match ttype {
TokenType::Plus => (Associativity::Left, Precedence::Term, Op::Add, None),
TokenType::Minus => (
Associativity::Left,
Precedence::Term,
Op::Subtract,
Some(Op::Negate),
),
TokenType::Slash => (Associativity::Left, Precedence::Factor, Op::Divide, None),
TokenType::Star => (Associativity::Left, Precedence::Factor, Op::Multiply, None),
_ => todo!(),
}
}
impl<'src> Parser<'src> {
fn new(sc: Scanner<'src>) -> Self {
Parser {
@@ -314,6 +298,8 @@ impl<'src> Parser<'src> {
match ttype {
Plus | Minus => Precedence::Term,
Star | Slash => Precedence::Factor,
EqualEqual | BangEqual => Precedence::Equality,
Greater | GreaterEqual | Less | LessEqual => Precedence::Comparison,
RightParen => Precedence::None,
_ => panic!("{:?}", ttype),
}
@@ -322,8 +308,9 @@ impl<'src> Parser<'src> {
fn associativity(prec: Precedence) -> Associativity {
use Precedence::*;
match prec {
Term | Factor => Associativity::Left,
Term | Factor | Equality | Comparison => Associativity::Left,
None => Associativity::Left,
Unary => Associativity::Right,
_ => Associativity::NonAssoc,
}
}
@@ -393,15 +380,19 @@ impl<'src> Parser<'src> {
// Generates code for rhs
self._expression(chunk, Self::precedence(op.ttype));
let op_decoded = match op.ttype {
TokenType::Plus => Op::Add,
TokenType::Minus => Op::Subtract,
TokenType::Star => Op::Multiply,
TokenType::Slash => Op::Divide,
match op.ttype {
TokenType::Plus => chunk.add_op(Op::Add, 0),
TokenType::Minus => chunk.add_op(Op::Subtract, 0),
TokenType::Star => chunk.add_op(Op::Multiply, 0),
TokenType::Slash => chunk.add_op(Op::Divide, 0),
TokenType::EqualEqual => chunk.add_op(Op::Equal, 0),
TokenType::Greater => chunk.add_op(Op::Greater, 0),
TokenType::Less => chunk.add_op(Op::Less, 0),
TokenType::BangEqual => chunk.add_op(Op::Equal, 0).add_op(Op::Not, 0),
TokenType::GreaterEqual => chunk.add_op(Op::Less, 0).add_op(Op::Not, 0),
TokenType::LessEqual => chunk.add_op(Op::Greater, 0).add_op(Op::Not, 0),
_ => todo!(),
};
chunk.add_op(op_decoded, 0);
}
}
@@ -529,10 +520,16 @@ mod tests {
#[test]
fn parse_bool_expression() {
let source = "!false";
let source = "!false == !true >= true <= false > true < false != true";
use crate::bc::Op::*;
let expected = Chunk::new_with(
vec![False, Not],
vec![
False, Not, True, Not, True, Less, Not,
False, Greater, Not,
True, Greater,
False, Less,
Equal,
True, Equal, Not],
vec![],
vec![],
);