From 519ee21bcb754bf972b5f127f17035c5efe196d0 Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Mon, 27 Dec 2021 15:39:17 +0300
Subject: [PATCH] internal: move block to prefix entry point

---
 crates/mbe/src/expander/matcher.rs | 12 ++++++------
 crates/parser/src/grammar.rs       |  4 ++++
 crates/parser/src/lib.rs           |  2 ++
 3 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/crates/mbe/src/expander/matcher.rs b/crates/mbe/src/expander/matcher.rs
index 3636979d00..621ff791d4 100644
--- a/crates/mbe/src/expander/matcher.rs
+++ b/crates/mbe/src/expander/matcher.rs
@@ -695,7 +695,11 @@ fn match_meta_var(kind: &str, input: &mut TtIter) -> ExpandResult<Option<Fragmen
         "ty" => ParserEntryPoint::Type,
         "pat" | "pat_param" => ParserEntryPoint::Pattern, // FIXME: edition2021
         "stmt" => ParserEntryPoint::Statement,
-        "block" => ParserEntryPoint::Block,
+        "block" => {
+            return input
+                .expect_fragment2(parser::PrefixEntryPoint::Block)
+                .map(|tt| tt.map(Fragment::Tokens));
+        }
         "meta" => ParserEntryPoint::MetaItem,
         "item" => ParserEntryPoint::Item,
         _ => {
@@ -725,7 +729,7 @@ fn match_meta_var(kind: &str, input: &mut TtIter) -> ExpandResult<Option<Fragmen
                         .map_err(|()| err!())
                 }
                 // `vis` is optional
-                "vis" => Ok(input.eat_vis()),
+                "vis" => Ok(input.expect_fragment2(parser::PrefixEntryPoint::Vis).value),
                 _ => Err(ExpandError::UnexpectedToken),
             };
             return tt_result.map(|it| it.map(Fragment::Tokens)).into();
@@ -894,10 +898,6 @@ impl<'a> TtIter<'a> {
         .into())
     }
 
-    fn eat_vis(&mut self) -> Option<tt::TokenTree> {
-        self.expect_fragment2(parser::PrefixEntryPoint::Vis).value
-    }
-
     fn eat_char(&mut self, c: char) -> Option<tt::TokenTree> {
         let mut fork = self.clone();
         match fork.expect_char(c) {
diff --git a/crates/parser/src/grammar.rs b/crates/parser/src/grammar.rs
index 1c58f217a3..cf17e8453b 100644
--- a/crates/parser/src/grammar.rs
+++ b/crates/parser/src/grammar.rs
@@ -53,6 +53,10 @@ pub(crate) mod entry {
         pub(crate) fn vis(p: &mut Parser) {
             let _ = opt_visibility(p, false);
         }
+
+        pub(crate) fn block(p: &mut Parser) {
+            expressions::block_expr(p);
+        }
     }
 }
 
diff --git a/crates/parser/src/lib.rs b/crates/parser/src/lib.rs
index f4ce5a21e8..778c8b10ec 100644
--- a/crates/parser/src/lib.rs
+++ b/crates/parser/src/lib.rs
@@ -52,12 +52,14 @@ pub use crate::{
 #[derive(Debug)]
 pub enum PrefixEntryPoint {
     Vis,
+    Block,
 }
 
 impl PrefixEntryPoint {
     pub fn parse(&self, input: &Input) -> Output {
         let entry_point: fn(&'_ mut parser::Parser) = match self {
             PrefixEntryPoint::Vis => grammar::entry::prefix::vis,
+            PrefixEntryPoint::Block => grammar::entry::prefix::block,
         };
         let mut p = parser::Parser::new(input);
         entry_point(&mut p);