58 lines
1.5 KiB
Rust
58 lines
1.5 KiB
Rust
use ra_syntax::{
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AstNode,
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SyntaxNode, SyntaxKind::*,
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ast::{self, AstToken},
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algo::generate,
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};
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/// If the node is on the beginning of the line, calculate indent.
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pub(crate) fn leading_indent(node: &SyntaxNode) -> Option<&str> {
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let prev = prev_leaf(node)?;
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let ws_text = ast::Whitespace::cast(prev)?.text();
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ws_text.rfind('\n').map(|pos| &ws_text[pos + 1..])
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}
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fn prev_leaf(node: &SyntaxNode) -> Option<&SyntaxNode> {
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generate(node.ancestors().find_map(SyntaxNode::prev_sibling), |it| {
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it.last_child()
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})
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.last()
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}
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pub(crate) fn extract_trivial_expression(block: &ast::Block) -> Option<&ast::Expr> {
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let expr = block.expr()?;
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if expr.syntax().text().contains('\n') {
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return None;
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}
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let non_trivial_children = block.syntax().children().filter(|it| match it.kind() {
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WHITESPACE | L_CURLY | R_CURLY => false,
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_ => it != &expr.syntax(),
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});
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if non_trivial_children.count() > 0 {
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return None;
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}
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Some(expr)
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}
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pub(crate) fn compute_ws(left: &SyntaxNode, right: &SyntaxNode) -> &'static str {
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match left.kind() {
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L_PAREN | L_BRACK => return "",
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L_CURLY => {
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if let USE_TREE = right.kind() {
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return "";
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}
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}
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_ => (),
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}
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match right.kind() {
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R_PAREN | R_BRACK => return "",
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R_CURLY => {
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if let USE_TREE = left.kind() {
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return "";
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}
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}
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DOT => return "",
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_ => (),
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}
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" "
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}
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