rust-analyzer

diff --git a/crates/hir-def/src/macro_expansion_tests/mod.rs b/crates/hir-def/src/macro_expansion_tests/mod.rs
index ec29940538..e315414e9b 100644
--- a/crates/hir-def/src/macro_expansion_tests/mod.rs
+++ b/crates/hir-def/src/macro_expansion_tests/mod.rs

@@ -25,7 +25,7 @@ use hir_expand::{

InFile, MacroFileId, MacroFileIdExt,

};

use span::Span;

-use stdx::format_to;

+use stdx::{format_to, format_to_acc};

use syntax::{

ast::{self, edit::IndentLevel},

AstNode,

@@ -149,8 +149,7 @@ pub fn identity_when_valid(_attr: TokenStream, item: TokenStream) -> TokenStream

if tree {

let tree = format!("{:#?}", parse.syntax_node())

.split_inclusive('\n')

- .map(|line| format!("// {line}"))

- .collect::<String>();

+ .fold(String::new(), |mut acc, line| format_to_acc!(acc, "// {line}"));

format_to!(expn_text, "\n{}", tree)

}

let range = call.syntax().text_range();

diff --git a/crates/ide-assists/src/tests/sourcegen.rs b/crates/ide-assists/src/tests/sourcegen.rs
index ad5ec83287..088d93f9a6 100644
--- a/crates/ide-assists/src/tests/sourcegen.rs
+++ b/crates/ide-assists/src/tests/sourcegen.rs

@@ -2,6 +2,7 @@

use std::{fmt, fs, path::Path};

+use stdx::format_to_acc;

use test_utils::project_root;

#[test]

@@ -172,8 +173,7 @@ impl fmt::Display for Assist {

fn hide_hash_comments(text: &str) -> String {

text.split('\n') // want final newline

.filter(|&it| !(it.starts_with("# ") || it == "#"))

- .map(|it| format!("{it}\n"))

- .collect()

+ .fold(String::new(), |mut acc, it| format_to_acc!(acc, "{it}\n"))

}

fn reveal_hash_comments(text: &str) -> String {

@@ -187,6 +187,5 @@ fn reveal_hash_comments(text: &str) -> String {

}

})

- .map(|it| format!("{it}\n"))

- .collect()

+ .fold(String::new(), |mut acc, it| format_to_acc!(acc, "{it}\n"))

}

diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index 54d96ab138..815f6ea12e 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs

@@ -32,6 +32,7 @@ use project_model::{

};

use rustc_hash::{FxHashMap, FxHashSet};

use serde::{de::DeserializeOwned, Deserialize};

+use stdx::format_to_acc;

use vfs::{AbsPath, AbsPathBuf};

use crate::{

@@ -2563,14 +2564,13 @@ fn field_props(field: &str, ty: &str, doc: &[&str], default: &str) -> serde_json

#[cfg(test)]

fn manual(fields: &[(&'static str, &'static str, &[&str], &str)]) -> String {

- fields

- .iter()

- .map(|(field, _ty, doc, default)| {

- let name = format!("rust-analyzer.{}", field.replace('_', "."));

- let doc = doc_comment_to_string(doc);

- if default.contains('\n') {

- format!(

- r#"[[{name}]]{name}::

+ fields.iter().fold(String::new(), |mut acc, (field, _ty, doc, default)| {

+ let name = format!("rust-analyzer.{}", field.replace('_', "."));

+ let doc = doc_comment_to_string(doc);

+ if default.contains('\n') {

+ format_to_acc!(

+ acc,

+ r#"[[{name}]]{name}::

Default:

@@ -2580,16 +2580,17 @@ Default:

{doc}

- )

- } else {

- format!("[[{name}]]{name} (default: `{default}`)::\n+\n--\n{doc}--\n")

- }

- })

- .collect::<String>()

+ )

+ } else {

+ format_to_acc!(acc, "[[{name}]]{name} (default: `{default}`)::\n+\n--\n{doc}--\n")

+ }

+ })

}

fn doc_comment_to_string(doc: &[&str]) -> String {

- doc.iter().map(|it| it.strip_prefix(' ').unwrap_or(it)).map(|it| format!("{it}\n")).collect()

+ doc.iter()

+ .map(|it| it.strip_prefix(' ').unwrap_or(it))

+ .fold(String::new(), |mut acc, it| format_to_acc!(acc, "{it}\n"))

}

#[cfg(test)]

diff --git a/crates/rust-analyzer/tests/slow-tests/main.rs b/crates/rust-analyzer/tests/slow-tests/main.rs
index f7f654b890..19890110d5 100644
--- a/crates/rust-analyzer/tests/slow-tests/main.rs
+++ b/crates/rust-analyzer/tests/slow-tests/main.rs

@@ -31,6 +31,7 @@ use lsp_types::{

};

use rust_analyzer::lsp::ext::{OnEnter, Runnables, RunnablesParams};

use serde_json::json;

+use stdx::format_to_acc;

use test_utils::skip_slow_tests;

use crate::{

@@ -591,8 +592,10 @@ fn diagnostics_dont_block_typing() {

return;

}

- let librs: String = (0..10).map(|i| format!("mod m{i};")).collect();

- let libs: String = (0..10).map(|i| format!("//- /src/m{i}.rs\nfn foo() {{}}\n\n")).collect();

+ let librs: String = (0..10).fold(String::new(), |mut acc, i| format_to_acc!(acc, "mod m{i};"));

+ let libs: String = (0..10).fold(String::new(), |mut acc, i| {

+ format_to_acc!(acc, "//- /src/m{i}.rs\nfn foo() {{}}\n\n")

+ });

let server = Project::with_fixture(&format!(

r#"

//- /Cargo.toml

diff --git a/crates/stdx/src/macros.rs b/crates/stdx/src/macros.rs
index d71e418c89..5713abb6fc 100644
--- a/crates/stdx/src/macros.rs
+++ b/crates/stdx/src/macros.rs

@@ -24,6 +24,22 @@ macro_rules! format_to {

};

}

+/// Appends formatted string to a `String` and returns the `String`.

+///

+/// Useful for folding iterators into a `String`.

+#[macro_export]

+macro_rules! format_to_acc {

+ ($buf:expr, $lit:literal $($arg:tt)*) => {

+ {

+ use ::std::fmt::Write as _;

+ // We can't do ::std::fmt::Write::write_fmt($buf, format_args!($lit $($arg)*))

+ // unfortunately, as that loses out on autoref behavior.

+ _ = $buf.write_fmt(format_args!($lit $($arg)*));

+ $buf

+ }

+ };

/// Generates `From` impls for `Enum E { Foo(Foo), Bar(Bar) }` enums

///

/// # Example

diff --git a/crates/syntax/src/ast/make.rs b/crates/syntax/src/ast/make.rs
index 62d64319e3..d5eda8f15e 100644
--- a/crates/syntax/src/ast/make.rs
+++ b/crates/syntax/src/ast/make.rs

@@ -9,10 +9,11 @@

//! API should require to assemble every node piecewise. The trick of

//! `parse(format!())` we use internally is an implementation detail -- long

//! term, it will be replaced with direct tree manipulation.

use itertools::Itertools;

use parser::T;

use rowan::NodeOrToken;

-use stdx::{format_to, never};

+use stdx::{format_to, format_to_acc, never};

use crate::{ast, utils::is_raw_identifier, AstNode, SourceFile, SyntaxKind, SyntaxToken};

@@ -759,15 +760,12 @@ pub fn match_arm_with_guard(

}

pub fn match_arm_list(arms: impl IntoIterator<Item = ast::MatchArm>) -> ast::MatchArmList {

- let arms_str = arms

- .into_iter()

- .map(|arm| {

- let needs_comma = arm.expr().map_or(true, |it| !it.is_block_like());

- let comma = if needs_comma { "," } else { "" };

- let arm = arm.syntax();

- format!(" {arm}{comma}\n")

- })

- .collect::<String>();

+ let arms_str = arms.into_iter().fold(String::new(), |mut acc, arm| {

+ let needs_comma = arm.expr().map_or(true, |it| !it.is_block_like());

+ let comma = if needs_comma { "," } else { "" };

+ let arm = arm.syntax();

+ format_to_acc!(acc, " {arm}{comma}\n")

+ });

return from_text(&arms_str);

fn from_text(text: &str) -> ast::MatchArmList {

diff --git a/crates/syntax/src/tests.rs b/crates/syntax/src/tests.rs
index 8ae1242cf7..4c0a538f71 100644
--- a/crates/syntax/src/tests.rs
+++ b/crates/syntax/src/tests.rs

@@ -11,6 +11,7 @@ use std::{

use ast::HasName;

use expect_test::expect_file;

use rayon::prelude::*;

+use stdx::format_to_acc;

use test_utils::{bench, bench_fixture, project_root};

use crate::{ast, fuzz, AstNode, SourceFile, SyntaxError};

@@ -104,10 +105,9 @@ fn self_hosting_parsing() {

.collect::<Vec<_>>();

if !errors.is_empty() {

- let errors = errors

- .into_iter()

- .map(|(path, err)| format!("{}: {:?}\n", path.display(), err[0]))

- .collect::<String>();

+ let errors = errors.into_iter().fold(String::new(), |mut acc, (path, err)| {

+ format_to_acc!(acc, "{}: {:?}\n", path.display(), err[0])

+ });

panic!("Parsing errors:\n{errors}\n");

}