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Fix binary expression parsing

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This commit is contained in:
Jeff 2024-09-17 13:24:45 -04:00
parent fd4ffeec7c
commit 0d55bb7244
1 changed files with 37 additions and 47 deletions
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84
dust-lang/src/parser/mod.rs
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@ -258,35 +258,6 @@ impl<'src> Parser<'src> {
let operator = self.previous_token.kind();
let rule = ParseRule::from(&operator);
self.parse(rule.precedence.increment())?;
let (right_instruction, right_position) =
self.chunk.pop_instruction(self.current_position)?;
let mut push_back_right = false;
let mut right_is_constant = false;
let right = match right_instruction.operation() {
Operation::LoadConstant => {
right_is_constant = true;
self.decrement_register()?;
right_instruction.first_argument()
}
Operation::GetLocal => {
self.decrement_register()?;
right_instruction.first_argument()
}
operation if operation.is_binary() => {
push_back_right = true;
self.current_register - 2
}
_ => {
push_back_right = true;
self.current_register - 1
}
};
let (left_instruction, left_position) =
self.chunk.pop_instruction(self.current_position)?;
let mut push_back_left = false;
@ -309,17 +280,35 @@ impl<'src> Parser<'src> {
}
};
let destination = if left_is_constant && right_is_constant {
self.current_register.saturating_sub(1)
} else {
self.current_register
self.parse(rule.precedence.increment())?;
let (right_instruction, right_position) =
self.chunk.pop_instruction(self.current_position)?;
let mut push_back_right = false;
let mut right_is_constant = false;
let right = match right_instruction.operation() {
Operation::LoadConstant => {
right_is_constant = true;
self.decrement_register()?;
right_instruction.first_argument()
}
Operation::GetLocal => {
self.decrement_register()?;
right_instruction.first_argument()
}
_ => {
push_back_right = true;
self.current_register - 1
}
};
let mut instruction = match operator {
TokenKind::Plus => Instruction::add(destination, left, right),
TokenKind::Minus => Instruction::subtract(destination, left, right),
TokenKind::Star => Instruction::multiply(destination, left, right),
TokenKind::Slash => Instruction::divide(destination, left, right),
TokenKind::Plus => Instruction::add(self.current_register, left, right),
TokenKind::Minus => Instruction::subtract(self.current_register, left, right),
TokenKind::Star => Instruction::multiply(self.current_register, left, right),
TokenKind::Slash => Instruction::divide(self.current_register, left, right),
_ => {
return Err(ParseError::ExpectedTokenMultiple {
expected: vec![
@ -342,15 +331,16 @@ impl<'src> Parser<'src> {
instruction.set_second_argument_to_constant();
}
if push_back_right {
self.emit_instruction(right_instruction, right_position);
}
if push_back_left {
self.emit_instruction(left_instruction, left_position);
}
if push_back_right {
self.emit_instruction(right_instruction, right_position);
}
self.emit_instruction(instruction, operator_position);
self.increment_register()?;
Ok(())
@ -439,10 +429,6 @@ impl<'src> Parser<'src> {
}
self.chunk.end_scope();
self.emit_instruction(
Instruction::close(self.current_register),
self.current_position,
);
Ok(())
}
@ -547,10 +533,12 @@ impl<'src> Parser<'src> {
self.advance()?;
prefix_parser(self, allow_assignment)?;
while precedence <= ParseRule::from(&self.current_token.kind()).precedence {
let mut infix_rule = ParseRule::from(&self.current_token.kind());
while precedence <= infix_rule.precedence {
self.advance()?;
if let Some(infix_parser) = ParseRule::from(&self.previous_token.kind()).infix {
if let Some(infix_parser) = infix_rule.infix {
log::trace!(
"Parsing {} as infix with precedence {precedence}",
self.previous_token,
@ -564,6 +552,8 @@ impl<'src> Parser<'src> {
}
infix_parser(self)?;
infix_rule = ParseRule::from(&self.current_token.kind());
} else {
break;
}