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Add precedent operators * and /

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Vili Sinervä 2025-01-28 17:15:28 +02:00
parent 3c45dcbb4c
commit 10f7e32046
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GPG key ID: DF8FEAF54EFAC996
1 changed files with 71 additions and 3 deletions
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74
src/compiler/parser.rs
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@ -83,18 +83,31 @@ fn parse_identifier<'source>(pos: &mut usize, tokens: &[Token<'source>]) -> Expr
Identifier(token.text)
}
fn parse_term<'source>(pos: &mut usize, tokens: &[Token<'source>]) -> Expression<'source> {
fn parse_factor<'source>(pos: &mut usize, tokens: &[Token<'source>]) -> Expression<'source> {
match peek(pos, tokens).token_type {
TokenType::Integer => parse_int_literal(pos, tokens),
TokenType::Identifier => parse_identifier(pos, tokens),
_ => panic!("Unexpected token {}", peek(pos, tokens)),
_ => panic!("Unexpected {}", peek(pos, tokens)),
}
}
fn parse_term<'source>(pos: &mut usize, tokens: &[Token<'source>]) -> Expression<'source> {
let mut left = parse_factor(pos, tokens);
while ["*", "/"].contains(&peek(pos, tokens).text) {
let operator_token = next_expect_strings(pos, tokens, &vec!["*", "/"]);
let right = parse_factor(pos, tokens);
left = BinaryOp(Box::new(left), operator_token.text, Box::new(right));
}
left
}
fn parse_expression<'source>(pos: &mut usize, tokens: &[Token<'source>]) -> Expression<'source> {
let mut left = parse_term(pos, tokens);
while vec!["+", "-"].contains(&peek(pos, tokens).text) {
while ["+", "-"].contains(&peek(pos, tokens).text) {
let operator_token = next_expect_strings(pos, tokens, &vec!["+", "-"]);
let right = parse_term(pos, tokens);
@ -138,6 +151,18 @@ mod tests {
result,
BinaryOp(Box::new(IntLiteral(4)), "-", Box::new(IntLiteral(56)))
);
let result = parse(&vec![new_int("1"), new_id("*"), new_int("2")]);
assert_eq!(
result,
BinaryOp(Box::new(IntLiteral(1)), "*", Box::new(IntLiteral(2)))
);
let result = parse(&vec![new_int("1"), new_id("/"), new_int("2")]);
assert_eq!(
result,
BinaryOp(Box::new(IntLiteral(1)), "/", Box::new(IntLiteral(2)))
);
}
#[test]
@ -177,4 +202,47 @@ mod tests {
)
);
}
#[test]
fn test_binary_op_precedence() {
let result = parse(&vec![
new_int("1"),
new_id("+"),
new_int("2"),
new_id("*"),
new_int("3"),
]);
assert_eq!(
result,
BinaryOp(
Box::new(IntLiteral(1)),
"+",
Box::new(BinaryOp(
Box::new(IntLiteral(2)),
"*",
Box::new(IntLiteral(3))
)),
)
);
let result = parse(&vec![
new_int("1"),
new_id("-"),
new_int("2"),
new_id("/"),
new_int("3"),
]);
assert_eq!(
result,
BinaryOp(
Box::new(IntLiteral(1)),
"-",
Box::new(BinaryOp(
Box::new(IntLiteral(2)),
"/",
Box::new(IntLiteral(3))
)),
)
);
}
}