Skip to content
This repository has been archived by the owner on Dec 18, 2019. It is now read-only.

Commit

Permalink
feat(parser) Introduce ternary operator.
Browse files Browse the repository at this point in the history
  • Loading branch information
@Hywan
Hywan committed Sep 16, 2017
1 parent 7c4e616 commit 96df199
Showing 1 changed file with 106 additions and 40 deletions.
146 changes: 106 additions & 40 deletions source/rules/expressions/assignment.rs
View file
Expand Up @@ -40,7 +40,8 @@ use super::super::expressions::expression;
use super::super::super::ast::{
NAryOperation,
BinaryOperator,
Expression
Expression,
TernaryOperator,
};
use super::super::super::tokens::Span;
use super::super::super::tokens;
Expand All @@ -50,16 +51,8 @@ named_attr!(
Recognize all assignment expressions.
"],
pub assignment<Span, Expression>,
call!(conditional)
);

named_attr!(
#[doc="
Recognize a conditional expression.
"],
pub conditional<Span, Expression>,
map_res!(
logical_or,
conditional,
nary_expression_mapper
)
);
Expand All @@ -69,6 +62,48 @@ fn nary_expression_mapper<'a>(nary_operation: NAryOperation<'a>) -> Result<Expre
Ok(Expression::NAryOperation(nary_operation))
}

named_attr!(
#[doc="
Recognize a conditional expression.
"],
pub conditional<Span, NAryOperation>,
do_parse!(
left_operand: logical_or >>
result: fold_many0!(
do_parse!(
first!(tag!(tokens::TERNARY_THEN)) >>
middle_operand: opt!(first!(expression)) >>
first!(tag!(tokens::TERNARY_ELSE)) >>
right_operand: first!(logical_or) >>
(middle_operand, right_operand)
),
left_operand,
|accumulator, (middle_operand, right_operand)| {
match middle_operand {
Some(middle_operand) => {
NAryOperation::Ternary {
operator : TernaryOperator::Conditional,
left_operand : Box::new(accumulator),
middle_operand: Box::new(middle_operand),
right_operand : Box::new(right_operand)
}
},

None => {
NAryOperation::Binary {
operator : BinaryOperator::Conditional,
left_operand : Box::new(accumulator),
right_operand: Box::new(right_operand)
}
}

}
}
) >>
(result)
)
);

macro_rules! binary_operation {
(
$parser_name:ident:
Expand All @@ -79,7 +114,7 @@ macro_rules! binary_operation {
named!(
$parser_name<Span, NAryOperation>,
do_parse!(
left_operand: first!($left_parser) >>
left_operand: $left_parser >>
result: fold_many0!(
preceded!(
first!(tag!(tokens::$operator_token)),
Expand Down Expand Up @@ -108,7 +143,7 @@ macro_rules! binary_operation {
named!(
$parser_name<Span, NAryOperation>,
do_parse!(
left_operand: first!($left_parser) >>
left_operand: $left_parser >>
result: fold_many0!(
do_parse!(
operator: first!(
Expand Down Expand Up @@ -210,15 +245,13 @@ named!(

#[cfg(test)]
mod tests {
use super::{
assignment,
conditional
};
use super::assignment;
use super::super::super::super::ast::{
BinaryOperator,
Expression,
Literal,
NAryOperation
NAryOperation,
TernaryOperator
};
use super::super::super::super::internal::Result;
use super::super::super::super::tokens::{
Expand All @@ -244,13 +277,69 @@ mod tests {
)
}

/// Build a ternary operation.
macro_rules! ternary_operation {
($operator:ident, $left_operand:expr, $middle_operand:expr, $right_operand:expr) => (
NAryOperation::Ternary {
operator : TernaryOperator::$operator,
left_operand : Box::new($left_operand),
middle_operand: Box::new($middle_operand),
right_operand : Box::new($right_operand)
}
)
}

/// Build a literal expression with an integer inside.
macro_rules! integer {
($value:expr, $span:expr) => (
Expression::Literal(Literal::Integer(Token::new($value, $span)))
)
}

#[test]
fn case_conditional() {
let input = Span::new(b"1 ? 2 : 3 ? 4 : 5");
let output = Result::Done(
Span::new_at(b"", 17, 1, 18),
Expression::NAryOperation(
ternary_operation!(
Conditional,
ternary_operation!(
Conditional,
nullary_operation!(integer!(1, Span::new(b"1"))),
integer!(2, Span::new_at(b"2", 4, 1, 5)),
nullary_operation!(integer!(3, Span::new_at(b"3", 8, 1, 9)))
),
integer!(4, Span::new_at(b"4", 12, 1, 13)),
nullary_operation!(integer!(5, Span::new_at(b"5", 16, 1, 17)))
)
)
);

assert_eq!(assignment(input), output);
}

#[test]
fn case_conditional_with_none_middle_operator() {
let input = Span::new(b"1 ?: 2 ? : 3");
let output = Result::Done(
Span::new_at(b"", 12, 1, 13),
Expression::NAryOperation(
binary_operation!(
Conditional,
binary_operation!(
Conditional,
nullary_operation!(integer!(1, Span::new(b"1"))),
nullary_operation!(integer!(2, Span::new_at(b"2", 5, 1, 6)))
),
nullary_operation!(integer!(3, Span::new_at(b"3", 11, 1, 12)))
)
)
);

assert_eq!(assignment(input), output);
}

#[test]
fn case_logical_or() {
let input = Span::new(b"1 || 2 || 3");
Expand All @@ -270,7 +359,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -292,7 +380,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -314,7 +401,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -336,7 +422,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -358,7 +443,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -380,7 +464,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -402,7 +485,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -424,7 +506,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -446,7 +527,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -468,7 +548,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -490,7 +569,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -512,7 +590,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -534,7 +611,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -556,7 +632,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -578,7 +653,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -600,7 +674,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -622,7 +695,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -644,7 +716,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -666,7 +737,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -688,7 +758,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -710,7 +779,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -732,7 +800,6 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}

#[test]
Expand All @@ -754,6 +821,5 @@ mod tests {
);

assert_eq!(assignment(input), output);
assert_eq!(conditional(input), output);
}
}

0 comments on commit 96df199

Please sign in to comment.