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use std::{
fmt::{
Debug,
Display,
Formatter,
Result as FmtResult,
},
marker::PhantomData,
};
#[derive(Debug)]
pub struct GenParserRequirement<'a, 'b, R1, R2>
where
R1: Debug + Display,
R2: Debug + Display,
{
requirement: R1,
generated: Option<R2>,
_a: PhantomData<&'a ()>,
_b: PhantomData<&'b ()>,
}
impl<'a, 'b, R1, R2> GenParserRequirement<'a, 'b, R1, R2>
where
R1: Debug + Display,
R2: Debug + Display,
{
pub fn new(requirement: R1, generated: Option<R2>) -> Self
{
Self {
requirement,
generated,
_a: PhantomData,
_b: PhantomData,
}
}
pub fn first(&self) -> &R1
{
&self.requirement
}
pub fn second(&self) -> Option<&R2>
{
self.generated.as_ref()
}
}
impl<'a, 'b, R1, R2> Display for GenParserRequirement<'a, 'b, R1, R2>
where
R1: Debug + Display,
R2: Debug + Display,
{
fn fmt(&self, f: &mut Formatter) -> FmtResult
{
if let Some(generated) = &self.generated
{
write!(f, "{} {}", self.requirement, generated)
}
else
{
write!(f, "({}) -> gen", self.requirement)
}
}
}