//! This crate provides some utilities for indenting rust code. //! use std::iter::successors; use itertools::Itertools; use ra_syntax::{ SyntaxNode, SyntaxKind::*, SyntaxToken, SyntaxKind, ast::{self, AstNode, AstToken}, }; 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 token in prev_tokens(node.first_token()?) { if let Some(ws) = ast::Whitespace::cast(token) { let ws_text = ws.text(); if let Some(pos) = ws_text.rfind('\n') { return Some(&ws_text[pos + 1..]); } } if token.text().contains('\n') { break; } } None } fn prev_tokens(token: SyntaxToken) -> impl Iterator<Item = SyntaxToken> { successors(token.prev_token(), |&token| token.prev_token()) } 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: SyntaxKind, right: SyntaxKind) -> &'static str { match left { L_PAREN | L_BRACK => return "", L_CURLY => { if let USE_TREE = right { return ""; } } _ => (), } match right { R_PAREN | R_BRACK => return "", R_CURLY => { if let USE_TREE = left { return ""; } } DOT => return "", _ => (), } " " }