bendns' repos / rust-analyzer
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internal: move visibility to a prefix entry point
Browse Source
Aleksey Kladov 2021-12-28
parent abc658a · commit 350d5dc
Diffstat
-rw-r--r--crates/mbe/src/expander/matcher.rs2
-rw-r--r--crates/mbe/src/tt_iter.rs57
-rw-r--r--crates/parser/src/grammar.rs4
-rw-r--r--crates/parser/src/lib.rs7
4 files changed, 62 insertions, 8 deletions
diff --git a/crates/mbe/src/expander/matcher.rs b/crates/mbe/src/expander/matcher.rs
index e589dc759f..3636979d00 100644
--- a/crates/mbe/src/expander/matcher.rs
+++ b/crates/mbe/src/expander/matcher.rs
@@ -895,7 +895,7 @@ impl<'a> TtIter<'a> {
}
fn eat_vis(&mut self) -> Option<tt::TokenTree> {
- self.expect_fragment(ParserEntryPoint::Visibility).value
+ self.expect_fragment2(parser::PrefixEntryPoint::Vis).value
}
fn eat_char(&mut self, c: char) -> Option<tt::TokenTree> {
diff --git a/crates/mbe/src/tt_iter.rs b/crates/mbe/src/tt_iter.rs
index 2d2dbd8994..03d0cbee8b 100644
--- a/crates/mbe/src/tt_iter.rs
+++ b/crates/mbe/src/tt_iter.rs
@@ -146,6 +146,63 @@ impl<'a> TtIter<'a> {
ExpandResult { value: res, err }
}
+ pub(crate) fn expect_fragment2(
+ &mut self,
+ entry_point: parser::PrefixEntryPoint,
+ ) -> ExpandResult<Option<tt::TokenTree>> {
+ let buffer = TokenBuffer::from_tokens(self.inner.as_slice());
+ let parser_input = to_parser_input(&buffer);
+ let tree_traversal = entry_point.parse(&parser_input);
+
+ let mut cursor = buffer.begin();
+ let mut error = false;
+ for step in tree_traversal.iter() {
+ match step {
+ parser::Step::Token { kind, mut n_input_tokens } => {
+ if kind == SyntaxKind::LIFETIME_IDENT {
+ n_input_tokens = 2;
+ }
+ for _ in 0..n_input_tokens {
+ cursor = cursor.bump_subtree();
+ }
+ }
+ parser::Step::Enter { .. } | parser::Step::Exit => (),
+ parser::Step::Error { .. } => error = true,
+ }
+ }
+
+ let mut err = if !cursor.is_root() || error {
+ Some(err!("expected {:?}", entry_point))
+ } else {
+ None
+ };
+
+ let mut curr = buffer.begin();
+ let mut res = vec![];
+
+ if cursor.is_root() {
+ while curr != cursor {
+ if let Some(token) = curr.token_tree() {
+ res.push(token);
+ }
+ curr = curr.bump();
+ }
+ }
+ self.inner = self.inner.as_slice()[res.len()..].iter();
+ if res.is_empty() && err.is_none() {
+ err = Some(err!("no tokens consumed"));
+ }
+ let res = match res.len() {
+ 1 => Some(res[0].cloned()),
+ 0 => None,
+ _ => Some(tt::TokenTree::Subtree(tt::Subtree {
+ delimiter: None,
+ token_trees: res.into_iter().map(|it| it.cloned()).collect(),
+ })),
+ };
+ ExpandResult { value: res, err }
+ }
+
pub(crate) fn peek_n(&self, n: usize) -> Option<&tt::TokenTree> {
self.inner.as_slice().get(n)
}
diff --git a/crates/parser/src/grammar.rs b/crates/parser/src/grammar.rs
index 86dce61da2..1c58f217a3 100644
--- a/crates/parser/src/grammar.rs
+++ b/crates/parser/src/grammar.rs
@@ -86,10 +86,6 @@ pub(crate) mod entry_points {
expressions::stmt(p, expressions::StmtWithSemi::Optional, false);
}
- pub(crate) fn visibility(p: &mut Parser) {
- let _ = opt_visibility(p, false);
- }
-
// Parse a meta item , which excluded [], e.g : #[ MetaItem ]
pub(crate) fn meta_item(p: &mut Parser) {
attributes::meta(p);
diff --git a/crates/parser/src/lib.rs b/crates/parser/src/lib.rs
index f0b93c4511..f4ce5a21e8 100644
--- a/crates/parser/src/lib.rs
+++ b/crates/parser/src/lib.rs
@@ -49,12 +49,13 @@ pub use crate::{
/// `Option<Output>`. The way MBE work, by the time we *try* to parse `$e:expr`
/// we already commit to expression. In other words, this API by design can't be
/// used to implement "rollback and try another alternative" logic.
+#[derive(Debug)]
pub enum PrefixEntryPoint {
Vis,
}
impl PrefixEntryPoint {
- pub fn parse(self, input: &Input) -> Output {
+ pub fn parse(&self, input: &Input) -> Output {
let entry_point: fn(&'_ mut parser::Parser) = match self {
PrefixEntryPoint::Vis => grammar::entry::prefix::vis,
};
@@ -80,7 +81,7 @@ pub enum ParserEntryPoint {
Pattern,
Item,
Block,
- Visibility,
+ // Visibility,
MetaItem,
Items,
Statements,
@@ -109,7 +110,7 @@ pub fn parse(inp: &Input, entry_point: ParserEntryPoint) -> Output {
ParserEntryPoint::Pattern => grammar::entry_points::pattern,
ParserEntryPoint::Item => grammar::entry_points::item,
ParserEntryPoint::Block => grammar::entry_points::block_expr,
- ParserEntryPoint::Visibility => grammar::entry_points::visibility,
+ // ParserEntryPoint::Visibility => grammar::entry_points::visibility,
ParserEntryPoint::MetaItem => grammar::entry_points::meta_item,
ParserEntryPoint::Statement => grammar::entry_points::stmt,
ParserEntryPoint::StatementOptionalSemi => grammar::entry_points::stmt_optional_semi,