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simplify

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This commit is contained in:
Aleksey Kladov
2019-09-02 18:51:03 +03:00
parent 32bebfaf0e
commit c89abd4262
6 changed files with 115 additions and 212 deletions
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122
crates/ra_mbe/src/mbe_expander.rs
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@@ -1,7 +1,9 @@
//! This module takes a (parsed) definition of `macro_rules` invocation, a
//! `tt::TokenTree` representing an argument of macro invocation, and produces a
//! `tt::TokenTree` for the result of the expansion.
use ra_parser::FragmentKind::*;
use ra_syntax::SmolStr;
/// This module takes a (parsed) definition of `macro_rules` invocation, a
/// `tt::TokenTree` representing an argument of macro invocation, and produces a
/// `tt::TokenTree` for the result of the expansion.
use rustc_hash::FxHashMap;
use tt::TokenId;
@@ -192,81 +194,11 @@ fn match_lhs(pattern: &crate::Subtree, input: &mut TtCursor) -> Result<Bindings,
crate::TokenTree::Leaf(leaf) => match leaf {
crate::Leaf::Var(crate::Var { text, kind }) => {
let kind = kind.clone().ok_or(ExpandError::UnexpectedToken)?;
match kind.as_str() {
"ident" => {
let ident =
input.eat_ident().ok_or(ExpandError::UnexpectedToken)?.clone();
res.inner.insert(
text.clone(),
Binding::Simple(tt::Leaf::from(ident).into()),
);
match match_meta_var(kind.as_str(), input)? {
Some(tt) => {
res.inner.insert(text.clone(), Binding::Simple(tt));
}
"path" => {
let path =
input.eat_path().ok_or(ExpandError::UnexpectedToken)?.clone();
res.inner.insert(text.clone(), Binding::Simple(path));
}
"expr" => {
let expr =
input.eat_expr().ok_or(ExpandError::UnexpectedToken)?.clone();
res.inner.insert(text.clone(), Binding::Simple(expr));
}
"ty" => {
let ty = input.eat_ty().ok_or(ExpandError::UnexpectedToken)?.clone();
res.inner.insert(text.clone(), Binding::Simple(ty));
}
"pat" => {
let pat = input.eat_pat().ok_or(ExpandError::UnexpectedToken)?.clone();
res.inner.insert(text.clone(), Binding::Simple(pat));
}
"stmt" => {
let pat = input.eat_stmt().ok_or(ExpandError::UnexpectedToken)?.clone();
res.inner.insert(text.clone(), Binding::Simple(pat));
}
"block" => {
let block =
input.eat_block().ok_or(ExpandError::UnexpectedToken)?.clone();
res.inner.insert(text.clone(), Binding::Simple(block));
}
"meta" => {
let meta =
input.eat_meta().ok_or(ExpandError::UnexpectedToken)?.clone();
res.inner.insert(text.clone(), Binding::Simple(meta));
}
"tt" => {
let token = input.eat().ok_or(ExpandError::UnexpectedToken)?.clone();
res.inner.insert(text.clone(), Binding::Simple(token));
}
"item" => {
let item =
input.eat_item().ok_or(ExpandError::UnexpectedToken)?.clone();
res.inner.insert(text.clone(), Binding::Simple(item));
}
"lifetime" => {
let lifetime =
input.eat_lifetime().ok_or(ExpandError::UnexpectedToken)?.clone();
res.inner.insert(text.clone(), Binding::Simple(lifetime));
}
"literal" => {
let literal =
input.eat_literal().ok_or(ExpandError::UnexpectedToken)?.clone();
res.inner.insert(
text.clone(),
Binding::Simple(tt::Leaf::from(literal).into()),
);
}
"vis" => {
// `vis` is optional
if let Some(vis) = input.try_eat_vis() {
let vis = vis.clone();
res.inner.insert(text.clone(), Binding::Simple(vis));
} else {
res.push_optional(&text);
}
}
_ => return Err(ExpandError::UnexpectedToken),
None => res.push_optional(text),
}
}
crate::Leaf::Punct(punct) => {
@@ -360,6 +292,42 @@ fn match_lhs(pattern: &crate::Subtree, input: &mut TtCursor) -> Result<Bindings,
Ok(res)
}
fn match_meta_var(kind: &str, input: &mut TtCursor) -> Result<Option<tt::TokenTree>, ExpandError> {
let fragment = match kind {
"path" => Path,
"expr" => Expr,
"ty" => Type,
"pat" => Pattern,
"stmt" => Statement,
"block" => Block,
"meta" => MetaItem,
"item" => Item,
_ => {
let binding = match kind {
"ident" => {
let ident = input.eat_ident().ok_or(ExpandError::UnexpectedToken)?.clone();
tt::Leaf::from(ident).into()
}
"tt" => input.eat().ok_or(ExpandError::UnexpectedToken)?.clone(),
"lifetime" => input.eat_lifetime().ok_or(ExpandError::UnexpectedToken)?.clone(),
"literal" => {
let literal = input.eat_literal().ok_or(ExpandError::UnexpectedToken)?.clone();
tt::Leaf::from(literal).into()
}
// `vis` is optional
"vis" => match input.try_eat_vis() {
Some(vis) => vis,
None => return Ok(None),
},
_ => return Err(ExpandError::UnexpectedToken),
};
return Ok(Some(binding));
}
};
let binding = input.eat_fragment(fragment).ok_or(ExpandError::UnexpectedToken)?;
Ok(Some(binding))
}
#[derive(Debug)]
struct ExpandCtx<'a> {
bindings: &'a Bindings,