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//! This crate provides some utilities for indenting rust code.
//!
use itertools::Itertools;
use ra_syntax::{
AstNode,
SyntaxNode, SyntaxKind::*,
ast::{self, AstToken},
algo::generate,
};
pub fn reindent(text: &str, indent: &str) -> String {
let indent = format!("\n{}", indent);
text.lines().intersperse(&indent).collect()
}
/// If the node is on the beginning of the line, calculate indent.
pub fn leading_indent(node: &SyntaxNode) -> Option<&str> {
for leaf in prev_leaves(node) {
if let Some(ws) = ast::Whitespace::cast(leaf) {
let ws_text = ws.text();
if let Some(pos) = ws_text.rfind('\n') {
return Some(&ws_text[pos + 1..]);
}
}
if leaf.leaf_text().unwrap().contains('\n') {
break;
}
}
None
}
fn prev_leaves(node: &SyntaxNode) -> impl Iterator<Item = &SyntaxNode> {
generate(prev_leaf(node), |&node| prev_leaf(node))
}
fn prev_leaf(node: &SyntaxNode) -> Option<&SyntaxNode> {
generate(node.ancestors().find_map(SyntaxNode::prev_sibling), |it| it.last_child()).last()
}
pub fn extract_trivial_expression(block: &ast::Block) -> Option<&ast::Expr> {
let expr = block.expr()?;
if expr.syntax().text().contains('\n') {
return None;
}
let non_trivial_children = block.syntax().children().filter(|it| match it.kind() {
WHITESPACE | L_CURLY | R_CURLY => false,
_ => it != &expr.syntax(),
});
if non_trivial_children.count() > 0 {
return None;
}
Some(expr)
}
pub fn compute_ws(left: &SyntaxNode, right: &SyntaxNode) -> &'static str {
match left.kind() {
L_PAREN | L_BRACK => return "",
L_CURLY => {
if let USE_TREE = right.kind() {
return "";
}
}
_ => (),
}
match right.kind() {
R_PAREN | R_BRACK => return "",
R_CURLY => {
if let USE_TREE = left.kind() {
return "";
}
}
DOT => return "",
_ => (),
}
" "
}
|
