bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/ide-db/src/syntax_helpers/insert_whitespace_into_node.rs')
-rw-r--r--crates/ide-db/src/syntax_helpers/insert_whitespace_into_node.rs119
1 files changed, 119 insertions, 0 deletions
diff --git a/crates/ide-db/src/syntax_helpers/insert_whitespace_into_node.rs b/crates/ide-db/src/syntax_helpers/insert_whitespace_into_node.rs
new file mode 100644
index 0000000000..e389eaf047
--- /dev/null
+++ b/crates/ide-db/src/syntax_helpers/insert_whitespace_into_node.rs
@@ -0,0 +1,119 @@
+//! Utilities for formatting macro expanded nodes until we get a proper formatter.
+use syntax::{
+ ast::make,
+ ted::{self, Position},
+ NodeOrToken,
+ SyntaxKind::{self, *},
+ SyntaxNode, SyntaxToken, WalkEvent, T,
+};
+
+// FIXME: It would also be cool to share logic here and in the mbe tests,
+// which are pretty unreadable at the moment.
+/// Renders a [`SyntaxNode`] with whitespace inserted between tokens that require them.
+pub fn insert_ws_into(syn: SyntaxNode) -> SyntaxNode {
+ let mut indent = 0;
+ let mut last: Option<SyntaxKind> = None;
+ let mut mods = Vec::new();
+ let syn = syn.clone_subtree().clone_for_update();
+
+ let before = Position::before;
+ let after = Position::after;
+
+ let do_indent = |pos: fn(_) -> Position, token: &SyntaxToken, indent| {
+ (pos(token.clone()), make::tokens::whitespace(&" ".repeat(2 * indent)))
+ };
+ let do_ws = |pos: fn(_) -> Position, token: &SyntaxToken| {
+ (pos(token.clone()), make::tokens::single_space())
+ };
+ let do_nl = |pos: fn(_) -> Position, token: &SyntaxToken| {
+ (pos(token.clone()), make::tokens::single_newline())
+ };
+
+ for event in syn.preorder_with_tokens() {
+ let token = match event {
+ WalkEvent::Enter(NodeOrToken::Token(token)) => token,
+ WalkEvent::Leave(NodeOrToken::Node(node))
+ if matches!(node.kind(), ATTR | MATCH_ARM | STRUCT | ENUM | UNION | FN | IMPL) =>
+ {
+ if indent > 0 {
+ mods.push((
+ Position::after(node.clone()),
+ make::tokens::whitespace(&" ".repeat(2 * indent)),
+ ));
+ }
+ if node.parent().is_some() {
+ mods.push((Position::after(node), make::tokens::single_newline()));
+ }
+ continue;
+ }
+ _ => continue,
+ };
+ let tok = &token;
+
+ let is_next = |f: fn(SyntaxKind) -> bool, default| -> bool {
+ tok.next_token().map(|it| f(it.kind())).unwrap_or(default)
+ };
+ let is_last =
+ |f: fn(SyntaxKind) -> bool, default| -> bool { last.map(f).unwrap_or(default) };
+
+ match tok.kind() {
+ k if is_text(k) && is_next(|it| !it.is_punct(), true) => {
+ mods.push(do_ws(after, tok));
+ }
+ L_CURLY if is_next(|it| it != R_CURLY, true) => {
+ indent += 1;
+ if is_last(is_text, false) {
+ mods.push(do_ws(before, tok));
+ }
+
+ if indent > 0 {
+ mods.push(do_indent(after, tok, indent));
+ }
+ mods.push(do_nl(after, tok));
+ }
+ R_CURLY if is_last(|it| it != L_CURLY, true) => {
+ indent = indent.saturating_sub(1);
+
+ if indent > 0 {
+ mods.push(do_indent(before, tok, indent));
+ }
+ mods.push(do_nl(before, tok));
+ }
+ R_CURLY => {
+ if indent > 0 {
+ mods.push(do_indent(after, tok, indent));
+ }
+ mods.push(do_nl(after, tok));
+ }
+ LIFETIME_IDENT if is_next(is_text, true) => {
+ mods.push(do_ws(after, tok));
+ }
+ AS_KW | DYN_KW | IMPL_KW | CONST_KW => {
+ mods.push(do_ws(after, tok));
+ }
+ T![;] => {
+ if indent > 0 {
+ mods.push(do_indent(after, tok, indent));
+ }
+ mods.push(do_nl(after, tok));
+ }
+ T![->] | T![=] | T![=>] => {
+ mods.push(do_ws(before, tok));
+ mods.push(do_ws(after, tok));
+ }
+ _ => (),
+ }
+
+ last = Some(tok.kind());
+ }
+
+ for (pos, insert) in mods {
+ ted::insert(pos, insert);
+ }
+
+ syn
+}
+
+fn is_text(k: SyntaxKind) -> bool {
+ k.is_keyword() || k.is_literal() || k == IDENT
+}