From 3f5fc05d6675394f46b7cdeb6803d7c7045e16ab Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Wed, 29 Dec 2021 18:23:34 +0300
Subject: [PATCH 1/7] internal: add tests for extra parser entry points
---
crates/parser/src/output.rs | 1 +
crates/parser/src/shortcuts.rs | 4 ++-
crates/parser/src/tests.rs | 1 +
crates/parser/src/tests/entries.rs | 41 ++++++++++++++++++++++++++++++
4 files changed, 46 insertions(+), 1 deletion(-)
create mode 100644 crates/parser/src/tests/entries.rs
diff --git a/crates/parser/src/output.rs b/crates/parser/src/output.rs
index b613df029f8..e9ec9822d68 100644
--- a/crates/parser/src/output.rs
+++ b/crates/parser/src/output.rs
@@ -22,6 +22,7 @@ pub struct Output {
error: Vec<String>,
}
+#[derive(Debug)]
pub enum Step<'a> {
Token { kind: SyntaxKind, n_input_tokens: u8 },
Enter { kind: SyntaxKind },
diff --git a/crates/parser/src/shortcuts.rs b/crates/parser/src/shortcuts.rs
index 3d28f814c9f..e14526aa733 100644
--- a/crates/parser/src/shortcuts.rs
+++ b/crates/parser/src/shortcuts.rs
@@ -16,6 +16,7 @@ use crate::{
SyntaxKind::{self, *},
};
+#[derive(Debug)]
pub enum StrStep<'a> {
Token { kind: SyntaxKind, text: &'a str },
Enter { kind: SyntaxKind },
@@ -75,7 +76,8 @@ impl<'a> LexedStr<'a> {
builder.eat_trivias();
(builder.sink)(StrStep::Exit);
}
- State::PendingEnter | State::Normal => unreachable!(),
+ State::PendingEnter => (),
+ State::Normal => unreachable!(),
}
let is_eof = builder.pos == builder.lexed.len();
diff --git a/crates/parser/src/tests.rs b/crates/parser/src/tests.rs
index 512f7ddb95b..fb4885e98d5 100644
--- a/crates/parser/src/tests.rs
+++ b/crates/parser/src/tests.rs
@@ -1,4 +1,5 @@
mod sourcegen_inline_tests;
+mod entries;
use std::{
fmt::Write,
diff --git a/crates/parser/src/tests/entries.rs b/crates/parser/src/tests/entries.rs
new file mode 100644
index 00000000000..93e8136263e
--- /dev/null
+++ b/crates/parser/src/tests/entries.rs
@@ -0,0 +1,41 @@
+use crate::{LexedStr, PrefixEntryPoint, StrStep};
+
+#[test]
+fn vis() {
+ check_prefix(PrefixEntryPoint::Vis, "pub(crate) fn foo() {}", "pub(crate)");
+ check_prefix(PrefixEntryPoint::Vis, "fn foo() {}", "");
+ check_prefix(PrefixEntryPoint::Vis, "pub(fn foo() {}", "pub");
+ check_prefix(PrefixEntryPoint::Vis, "pub(crate fn foo() {}", "pub(crate");
+ check_prefix(PrefixEntryPoint::Vis, "crate fn foo() {}", "crate");
+}
+
+#[test]
+fn block() {
+ check_prefix(PrefixEntryPoint::Block, "{}, 92", "{}");
+ check_prefix(PrefixEntryPoint::Block, "{, 92)", "{, 92)");
+ check_prefix(PrefixEntryPoint::Block, "()", "");
+}
+
+#[test]
+fn stmt() {
+ check_prefix(PrefixEntryPoint::Stmt, "92; fn", "92");
+ check_prefix(PrefixEntryPoint::Stmt, "let _ = 92; 1", "let _ = 92");
+ check_prefix(PrefixEntryPoint::Stmt, "pub fn f() {} = 92", "pub fn f() {}");
+ check_prefix(PrefixEntryPoint::Stmt, ";;;", ";");
+ check_prefix(PrefixEntryPoint::Stmt, "+", "+");
+ check_prefix(PrefixEntryPoint::Stmt, "@", "@");
+ check_prefix(PrefixEntryPoint::Stmt, "loop {} - 1", "loop {}");
+}
+
+fn check_prefix(entry: PrefixEntryPoint, input: &str, prefix: &str) {
+ let lexed = LexedStr::new(input);
+ let input = lexed.to_input();
+ let output = entry.parse(&input);
+
+ let mut buf = String::new();
+ lexed.intersperse_trivia(&output, &mut |step| match step {
+ StrStep::Token { kind: _, text } => buf.push_str(text),
+ _ => (),
+ });
+ assert_eq!(buf.trim(), prefix)
+}
From ad4b02ecc00977538cf7225a8b47cfc76d386221 Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Wed, 29 Dec 2021 18:37:06 +0300
Subject: [PATCH 2/7] add automated semicolon insertion test
---
.../hir_def/src/macro_expansion_tests/mbe.rs | 28 +++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/crates/hir_def/src/macro_expansion_tests/mbe.rs b/crates/hir_def/src/macro_expansion_tests/mbe.rs
index 466c85fc5b0..4bef508840d 100644
--- a/crates/hir_def/src/macro_expansion_tests/mbe.rs
+++ b/crates/hir_def/src/macro_expansion_tests/mbe.rs
@@ -299,6 +299,34 @@ fn baz() {
)
}
+#[test]
+fn asi() {
+ // Thanks, Christopher!
+ //
+ // https://internals.rust-lang.org/t/understanding-decisions-behind-semicolons/15181/29
+ check(
+ r#"
+macro_rules! asi { ($($stmt:stmt)*) => ($($stmt)*); }
+
+fn main() {
+ asi! {
+ let a = 2
+ let b = 5
+ drop(b-a)
+ println!("{}", a+b)
+ }
+}
+"#,
+ expect![[r#"
+macro_rules! asi { ($($stmt:stmt)*) => ($($stmt)*); }
+
+fn main() {
+ let a = 2let b = 5drop(b-a)println!("{}", a+b)
+}
+"#]],
+ )
+}
+
#[test]
fn test_match_group_empty_fixed_token() {
check(
From 8234a85d158ec83581d970a4a669f97b07c56c2f Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Wed, 29 Dec 2021 18:51:05 +0300
Subject: [PATCH 3/7] compress
---
crates/parser/src/grammar.rs | 4 ++--
crates/parser/src/grammar/expressions.rs | 7 ++++---
2 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/crates/parser/src/grammar.rs b/crates/parser/src/grammar.rs
index 42426a1df28..234e584eeb7 100644
--- a/crates/parser/src/grammar.rs
+++ b/crates/parser/src/grammar.rs
@@ -59,7 +59,7 @@ pub(crate) mod entry {
}
pub(crate) fn stmt(p: &mut Parser) {
- expressions::stmt(p, expressions::StmtWithSemi::No, true);
+ expressions::stmt(p, expressions::StmtWithSemi::No);
}
pub(crate) fn pat(p: &mut Parser) {
@@ -103,7 +103,7 @@ pub(crate) mod entry {
continue;
}
- expressions::stmt(p, expressions::StmtWithSemi::Optional, true);
+ expressions::stmt(p, expressions::StmtWithSemi::Optional);
}
m.complete(p, MACRO_STMTS);
diff --git a/crates/parser/src/grammar/expressions.rs b/crates/parser/src/grammar/expressions.rs
index 64057a4a674..3238b6e9f44 100644
--- a/crates/parser/src/grammar/expressions.rs
+++ b/crates/parser/src/grammar/expressions.rs
@@ -5,6 +5,7 @@ use super::*;
pub(crate) use self::atom::{block_expr, match_arm_list};
pub(super) use self::atom::{literal, LITERAL_FIRST};
+#[derive(PartialEq, Eq)]
pub(super) enum StmtWithSemi {
Yes,
No,
@@ -28,7 +29,7 @@ fn expr_no_struct(p: &mut Parser) {
expr_bp(p, None, r, 1);
}
-pub(super) fn stmt(p: &mut Parser, with_semi: StmtWithSemi, prefer_expr: bool) {
+pub(super) fn stmt(p: &mut Parser, with_semi: StmtWithSemi) {
let m = p.start();
// test attr_on_expr_stmt
// fn foo() {
@@ -52,7 +53,7 @@ pub(super) fn stmt(p: &mut Parser, with_semi: StmtWithSemi, prefer_expr: bool) {
};
if let Some((cm, blocklike)) = expr_stmt(p, Some(m)) {
- if !(p.at(T!['}']) || (prefer_expr && p.at(EOF))) {
+ if !(p.at(T!['}']) || (with_semi != StmtWithSemi::Yes && p.at(EOF))) {
// test no_semi_after_block
// fn foo() {
// if true {}
@@ -149,7 +150,7 @@ pub(super) fn expr_block_contents(p: &mut Parser) {
continue;
}
- stmt(p, StmtWithSemi::Yes, false);
+ stmt(p, StmtWithSemi::Yes);
}
}
From f5cfc0504e30b2e87dc9405fc3aeaee8e2fa6b08 Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Wed, 29 Dec 2021 19:18:34 +0300
Subject: [PATCH 4/7] rename
---
crates/parser/src/grammar.rs | 4 +--
crates/parser/src/grammar/expressions.rs | 35 ++++++++++++------------
2 files changed, 19 insertions(+), 20 deletions(-)
diff --git a/crates/parser/src/grammar.rs b/crates/parser/src/grammar.rs
index 234e584eeb7..b704242065c 100644
--- a/crates/parser/src/grammar.rs
+++ b/crates/parser/src/grammar.rs
@@ -59,7 +59,7 @@ pub(crate) mod entry {
}
pub(crate) fn stmt(p: &mut Parser) {
- expressions::stmt(p, expressions::StmtWithSemi::No);
+ expressions::stmt(p, expressions::Semicolon::Forbidden);
}
pub(crate) fn pat(p: &mut Parser) {
@@ -103,7 +103,7 @@ pub(crate) mod entry {
continue;
}
- expressions::stmt(p, expressions::StmtWithSemi::Optional);
+ expressions::stmt(p, expressions::Semicolon::Optional);
}
m.complete(p, MACRO_STMTS);
diff --git a/crates/parser/src/grammar/expressions.rs b/crates/parser/src/grammar/expressions.rs
index 3238b6e9f44..c585fdb0967 100644
--- a/crates/parser/src/grammar/expressions.rs
+++ b/crates/parser/src/grammar/expressions.rs
@@ -6,10 +6,10 @@ pub(crate) use self::atom::{block_expr, match_arm_list};
pub(super) use self::atom::{literal, LITERAL_FIRST};
#[derive(PartialEq, Eq)]
-pub(super) enum StmtWithSemi {
- Yes,
- No,
+pub(super) enum Semicolon {
+ Required,
Optional,
+ Forbidden,
}
const EXPR_FIRST: TokenSet = LHS_FIRST;
@@ -29,7 +29,7 @@ fn expr_no_struct(p: &mut Parser) {
expr_bp(p, None, r, 1);
}
-pub(super) fn stmt(p: &mut Parser, with_semi: StmtWithSemi) {
+pub(super) fn stmt(p: &mut Parser, semicolon: Semicolon) {
let m = p.start();
// test attr_on_expr_stmt
// fn foo() {
@@ -41,7 +41,7 @@ pub(super) fn stmt(p: &mut Parser, with_semi: StmtWithSemi) {
attributes::outer_attrs(p);
if p.at(T![let]) {
- let_stmt(p, m, with_semi);
+ let_stmt(p, m, semicolon);
return;
}
@@ -53,7 +53,7 @@ pub(super) fn stmt(p: &mut Parser, with_semi: StmtWithSemi) {
};
if let Some((cm, blocklike)) = expr_stmt(p, Some(m)) {
- if !(p.at(T!['}']) || (with_semi != StmtWithSemi::Yes && p.at(EOF))) {
+ if !(p.at(T!['}']) || (semicolon != Semicolon::Required && p.at(EOF))) {
// test no_semi_after_block
// fn foo() {
// if true {}
@@ -69,27 +69,26 @@ pub(super) fn stmt(p: &mut Parser, with_semi: StmtWithSemi) {
// test!{}
// }
let m = cm.precede(p);
- match with_semi {
- StmtWithSemi::No => (),
- StmtWithSemi::Optional => {
- p.eat(T![;]);
- }
- StmtWithSemi::Yes => {
+ match semicolon {
+ Semicolon::Required => {
if blocklike.is_block() {
p.eat(T![;]);
} else {
p.expect(T![;]);
}
}
+ Semicolon::Optional => {
+ p.eat(T![;]);
+ }
+ Semicolon::Forbidden => (),
}
-
m.complete(p, EXPR_STMT);
}
}
// test let_stmt
// fn f() { let x: i32 = 92; }
- fn let_stmt(p: &mut Parser, m: Marker, with_semi: StmtWithSemi) {
+ fn let_stmt(p: &mut Parser, m: Marker, with_semi: Semicolon) {
p.bump(T![let]);
patterns::pattern(p);
if p.at(T![:]) {
@@ -114,11 +113,11 @@ pub(super) fn stmt(p: &mut Parser, with_semi: StmtWithSemi) {
}
match with_semi {
- StmtWithSemi::No => (),
- StmtWithSemi::Optional => {
+ Semicolon::Forbidden => (),
+ Semicolon::Optional => {
p.eat(T![;]);
}
- StmtWithSemi::Yes => {
+ Semicolon::Required => {
p.expect(T![;]);
}
}
@@ -150,7 +149,7 @@ pub(super) fn expr_block_contents(p: &mut Parser) {
continue;
}
- stmt(p, StmtWithSemi::Yes);
+ stmt(p, Semicolon::Required);
}
}
From 841cd30b451ee80c54c47e9b0c6ea42ae2de4795 Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Wed, 29 Dec 2021 19:37:35 +0300
Subject: [PATCH 5/7] Add test
---
.../hir_def/src/macro_expansion_tests/mbe.rs | 28 -----------
.../src/macro_expansion_tests/mbe/matching.rs | 49 +++++++++++++++++++
2 files changed, 49 insertions(+), 28 deletions(-)
diff --git a/crates/hir_def/src/macro_expansion_tests/mbe.rs b/crates/hir_def/src/macro_expansion_tests/mbe.rs
index 4bef508840d..466c85fc5b0 100644
--- a/crates/hir_def/src/macro_expansion_tests/mbe.rs
+++ b/crates/hir_def/src/macro_expansion_tests/mbe.rs
@@ -299,34 +299,6 @@ fn baz() {
)
}
-#[test]
-fn asi() {
- // Thanks, Christopher!
- //
- // https://internals.rust-lang.org/t/understanding-decisions-behind-semicolons/15181/29
- check(
- r#"
-macro_rules! asi { ($($stmt:stmt)*) => ($($stmt)*); }
-
-fn main() {
- asi! {
- let a = 2
- let b = 5
- drop(b-a)
- println!("{}", a+b)
- }
-}
-"#,
- expect![[r#"
-macro_rules! asi { ($($stmt:stmt)*) => ($($stmt)*); }
-
-fn main() {
- let a = 2let b = 5drop(b-a)println!("{}", a+b)
-}
-"#]],
- )
-}
-
#[test]
fn test_match_group_empty_fixed_token() {
check(
diff --git a/crates/hir_def/src/macro_expansion_tests/mbe/matching.rs b/crates/hir_def/src/macro_expansion_tests/mbe/matching.rs
index 9fb6d96b725..83e8937f5b1 100644
--- a/crates/hir_def/src/macro_expansion_tests/mbe/matching.rs
+++ b/crates/hir_def/src/macro_expansion_tests/mbe/matching.rs
@@ -50,3 +50,52 @@ macro_rules! m{ ($fmt:expr) => (); }
"#]],
);
}
+
+#[test]
+fn asi() {
+ // Thanks, Christopher!
+ //
+ // https://internals.rust-lang.org/t/understanding-decisions-behind-semicolons/15181/29
+ check(
+ r#"
+macro_rules! asi { ($($stmt:stmt)*) => ($($stmt)*); }
+
+fn main() {
+ asi! {
+ let a = 2
+ let b = 5
+ drop(b-a)
+ println!("{}", a+b)
+ }
+}
+"#,
+ expect![[r#"
+macro_rules! asi { ($($stmt:stmt)*) => ($($stmt)*); }
+
+fn main() {
+ let a = 2let b = 5drop(b-a)println!("{}", a+b)
+}
+"#]],
+ )
+}
+
+#[test]
+fn stmt_boundaries() {
+ // FIXME: this actually works OK under rustc.
+ check(
+ r#"
+macro_rules! m {
+ ($($s:stmt)*) => (stringify!($($s |)*))
+}
+// +errors
+m!(;;92;let x = 92; loop {};);
+"#,
+ expect![[r#"
+macro_rules! m {
+ ($($s:stmt)*) => (stringify!($($s |)*))
+}
+/* error: expected Stmt *//* parse error: expected SEMICOLON */
+stringify!()
+"#]],
+ );
+}
From b5369927d79d1f95b9748ded2523a65b72f05a1d Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Wed, 29 Dec 2021 20:04:36 +0300
Subject: [PATCH 6/7] parse empty statemet as statemetn
---
.../src/macro_expansion_tests/mbe/matching.rs | 14 +++++++++-----
crates/parser/src/grammar.rs | 5 -----
crates/parser/src/grammar/expressions.rs | 10 ++++------
crates/parser/src/shortcuts.rs | 6 ++----
4 files changed, 15 insertions(+), 20 deletions(-)
diff --git a/crates/hir_def/src/macro_expansion_tests/mbe/matching.rs b/crates/hir_def/src/macro_expansion_tests/mbe/matching.rs
index 83e8937f5b1..b93072d4466 100644
--- a/crates/hir_def/src/macro_expansion_tests/mbe/matching.rs
+++ b/crates/hir_def/src/macro_expansion_tests/mbe/matching.rs
@@ -85,17 +85,21 @@ fn stmt_boundaries() {
check(
r#"
macro_rules! m {
- ($($s:stmt)*) => (stringify!($($s |)*))
+ ($($s:stmt)*) => (stringify!($($s |)*);)
}
-// +errors
m!(;;92;let x = 92; loop {};);
"#,
expect![[r#"
macro_rules! m {
- ($($s:stmt)*) => (stringify!($($s |)*))
+ ($($s:stmt)*) => (stringify!($($s |)*);)
}
-/* error: expected Stmt *//* parse error: expected SEMICOLON */
-stringify!()
+stringify!(;
+|;
+|92|;
+|let x = 92|;
+|loop {}
+|;
+|);
"#]],
);
}
diff --git a/crates/parser/src/grammar.rs b/crates/parser/src/grammar.rs
index b704242065c..e1a265d817c 100644
--- a/crates/parser/src/grammar.rs
+++ b/crates/parser/src/grammar.rs
@@ -98,11 +98,6 @@ pub(crate) mod entry {
let m = p.start();
while !p.at(EOF) {
- if p.at(T![;]) {
- p.bump(T![;]);
- continue;
- }
-
expressions::stmt(p, expressions::Semicolon::Optional);
}
diff --git a/crates/parser/src/grammar/expressions.rs b/crates/parser/src/grammar/expressions.rs
index c585fdb0967..9dbba89c568 100644
--- a/crates/parser/src/grammar/expressions.rs
+++ b/crates/parser/src/grammar/expressions.rs
@@ -30,6 +30,10 @@ fn expr_no_struct(p: &mut Parser) {
}
pub(super) fn stmt(p: &mut Parser, semicolon: Semicolon) {
+ if p.eat(T![;]) {
+ return;
+ }
+
let m = p.start();
// test attr_on_expr_stmt
// fn foo() {
@@ -143,12 +147,6 @@ pub(super) fn expr_block_contents(p: &mut Parser) {
// fn f() {};
// struct S {};
// }
-
- if p.at(T![;]) {
- p.bump(T![;]);
- continue;
- }
-
stmt(p, Semicolon::Required);
}
}
diff --git a/crates/parser/src/shortcuts.rs b/crates/parser/src/shortcuts.rs
index e14526aa733..7040608a9f7 100644
--- a/crates/parser/src/shortcuts.rs
+++ b/crates/parser/src/shortcuts.rs
@@ -76,8 +76,7 @@ impl<'a> LexedStr<'a> {
builder.eat_trivias();
(builder.sink)(StrStep::Exit);
}
- State::PendingEnter => (),
- State::Normal => unreachable!(),
+ State::PendingEnter | State::Normal => (),
}
let is_eof = builder.pos == builder.lexed.len();
@@ -101,9 +100,8 @@ enum State {
impl Builder<'_, '_> {
fn token(&mut self, kind: SyntaxKind, n_tokens: u8) {
match mem::replace(&mut self.state, State::Normal) {
- State::PendingEnter => unreachable!(),
State::PendingExit => (self.sink)(StrStep::Exit),
- State::Normal => (),
+ State::PendingEnter | State::Normal => (),
}
self.eat_trivias();
self.do_token(kind, n_tokens as usize);
From 2f3237912dd557493560f76a9fbbd7926b7933a5 Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Wed, 29 Dec 2021 20:37:08 +0300
Subject: [PATCH 7/7] restore invariatns
---
crates/parser/src/shortcuts.rs | 6 ++++--
crates/parser/src/tests/entries.rs | 29 +++++++++++++++++++++--------
2 files changed, 25 insertions(+), 10 deletions(-)
diff --git a/crates/parser/src/shortcuts.rs b/crates/parser/src/shortcuts.rs
index 7040608a9f7..b038d44fe08 100644
--- a/crates/parser/src/shortcuts.rs
+++ b/crates/parser/src/shortcuts.rs
@@ -50,6 +50,7 @@ impl<'a> LexedStr<'a> {
res
}
+ /// NB: only valid to call with Output from Reparser/TopLevelEntry.
pub fn intersperse_trivia(
&self,
output: &crate::Output,
@@ -76,7 +77,7 @@ impl<'a> LexedStr<'a> {
builder.eat_trivias();
(builder.sink)(StrStep::Exit);
}
- State::PendingEnter | State::Normal => (),
+ State::PendingEnter | State::Normal => unreachable!(),
}
let is_eof = builder.pos == builder.lexed.len();
@@ -100,8 +101,9 @@ enum State {
impl Builder<'_, '_> {
fn token(&mut self, kind: SyntaxKind, n_tokens: u8) {
match mem::replace(&mut self.state, State::Normal) {
+ State::PendingEnter => unreachable!(),
State::PendingExit => (self.sink)(StrStep::Exit),
- State::PendingEnter | State::Normal => (),
+ State::Normal => (),
}
self.eat_trivias();
self.do_token(kind, n_tokens as usize);
diff --git a/crates/parser/src/tests/entries.rs b/crates/parser/src/tests/entries.rs
index 93e8136263e..947922d8b32 100644
--- a/crates/parser/src/tests/entries.rs
+++ b/crates/parser/src/tests/entries.rs
@@ -1,4 +1,4 @@
-use crate::{LexedStr, PrefixEntryPoint, StrStep};
+use crate::{LexedStr, PrefixEntryPoint, Step};
#[test]
fn vis() {
@@ -30,12 +30,25 @@ fn stmt() {
fn check_prefix(entry: PrefixEntryPoint, input: &str, prefix: &str) {
let lexed = LexedStr::new(input);
let input = lexed.to_input();
- let output = entry.parse(&input);
- let mut buf = String::new();
- lexed.intersperse_trivia(&output, &mut |step| match step {
- StrStep::Token { kind: _, text } => buf.push_str(text),
- _ => (),
- });
- assert_eq!(buf.trim(), prefix)
+ let mut n_tokens = 0;
+ for step in entry.parse(&input).iter() {
+ match step {
+ Step::Token { n_input_tokens, .. } => n_tokens += n_input_tokens as usize,
+ Step::Enter { .. } | Step::Exit | Step::Error { .. } => (),
+ }
+ }
+
+ let mut i = 0;
+ loop {
+ if n_tokens == 0 {
+ break;
+ }
+ if !lexed.kind(i).is_trivia() {
+ n_tokens -= 1;
+ }
+ i += 1;
+ }
+ let buf = &lexed.as_str()[..lexed.text_start(i)];
+ assert_eq!(buf, prefix);
}