organic/src/iter/macros.rs

122 lines
3.3 KiB
Rust

/// Create iterators for ast nodes where it only has to iterate over children
macro_rules! children_iter {
($astnodetype:ty, $itertype:ident, $innertype:ty) => {
pub struct $itertype<'r, 's> {
next: $innertype,
}
impl<'r, 's> Iterator for $itertype<'r, 's> {
type Item = AstNode<'r, 's>;
fn next(&mut self) -> Option<Self::Item> {
self.next.next().map(Into::<AstNode>::into)
}
fn size_hint(&self) -> (usize, Option<usize>) {
let size = self.next.len();
(size, Some(size))
}
}
impl<'r, 's> ExactSizeIterator for $itertype<'r, 's> {}
impl<'r, 's> IntoIterator for &'r $astnodetype {
type Item = AstNode<'r, 's>;
type IntoIter = $itertype<'r, 's>;
fn into_iter(self) -> Self::IntoIter {
$itertype {
next: self.children.iter(),
}
}
}
};
}
pub(crate) use children_iter;
/// Create iterators for ast nodes that do not contain any ast node children.
macro_rules! empty_iter {
($astnodetype:ty, $itertype:ident) => {
pub struct $itertype<'r, 's> {
phantom: PhantomData<&'r $astnodetype>,
}
impl<'r, 's> Iterator for $itertype<'r, 's> {
type Item = AstNode<'r, 's>;
fn next(&mut self) -> Option<Self::Item> {
None
}
fn size_hint(&self) -> (usize, Option<usize>) {
(0, Some(0))
}
}
impl<'r, 's> ExactSizeIterator for $itertype<'r, 's> {}
impl<'r, 's> IntoIterator for &'r $astnodetype {
type Item = AstNode<'r, 's>;
type IntoIter = $itertype<'r, 's>;
fn into_iter(self) -> Self::IntoIter {
$itertype {
phantom: PhantomData,
}
}
}
};
}
pub(crate) use empty_iter;
/// Create iterators for ast nodes where it has to iterate over multiple child lists.
macro_rules! multi_field_iter {
($astnodetype:ty, $itertype:ident, $firstfieldname: ident, $firstinnertype:ty, $($fieldname: ident, $innertype:ty),*) => {
pub struct $itertype<'r, 's> {
$firstfieldname: $firstinnertype,
$(
$fieldname: $innertype,
),*
}
impl<'r, 's> Iterator for $itertype<'r, 's> {
type Item = AstNode<'r, 's>;
fn next(&mut self) -> Option<Self::Item> {
self.$firstfieldname.next().map(Into::<AstNode>::into)
$(
.or_else(|| self.$fieldname.next().map(Into::<AstNode>::into))
),*
}
fn size_hint(&self) -> (usize, Option<usize>) {
let size = self.$firstfieldname.len()$( + self.$fieldname.len() ),*;
(size, Some(size))
}
}
impl<'r, 's> ExactSizeIterator for $itertype<'r, 's> {}
impl<'r, 's> IntoIterator for &'r $astnodetype {
type Item = AstNode<'r, 's>;
type IntoIter = $itertype<'r, 's>;
fn into_iter(self) -> Self::IntoIter {
$itertype {
$firstfieldname: self.$firstfieldname.iter(),
$(
$fieldname: self.$fieldname.iter(),
),*
}
}
}
};
}
pub(crate) use multi_field_iter;