106 lines
3.5 KiB
Rust
106 lines
3.5 KiB
Rust
use syntax::{
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File, TextRange, SyntaxNodeRef, TextUnit,
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SyntaxKind::*,
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algo::{find_leaf_at_offset, LeafAtOffset, find_covering_node, ancestors, Direction, siblings},
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};
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pub fn extend_selection(file: &File, range: TextRange) -> Option<TextRange> {
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let syntax = file.syntax();
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extend(syntax.borrowed(), range)
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}
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pub(crate) fn extend(root: SyntaxNodeRef, range: TextRange) -> Option<TextRange> {
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if range.is_empty() {
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let offset = range.start();
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let mut leaves = find_leaf_at_offset(root, offset);
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if leaves.clone().all(|it| it.kind() == WHITESPACE) {
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return Some(extend_ws(root, leaves.next()?, offset));
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}
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let leaf = match leaves {
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LeafAtOffset::None => return None,
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LeafAtOffset::Single(l) => l,
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LeafAtOffset::Between(l, r) => pick_best(l, r),
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};
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return Some(leaf.range());
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};
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let node = find_covering_node(root, range);
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if node.kind() == COMMENT && range == node.range() {
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if let Some(range) = extend_comments(node) {
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return Some(range);
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}
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}
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match ancestors(node).skip_while(|n| n.range() == range).next() {
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None => None,
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Some(parent) => Some(parent.range()),
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}
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}
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fn extend_ws(root: SyntaxNodeRef, ws: SyntaxNodeRef, offset: TextUnit) -> TextRange {
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let ws_text = ws.leaf_text().unwrap();
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let suffix = TextRange::from_to(offset, ws.range().end()) - ws.range().start();
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let prefix = TextRange::from_to(ws.range().start(), offset) - ws.range().start();
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let ws_suffix = &ws_text.as_str()[suffix];
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let ws_prefix = &ws_text.as_str()[prefix];
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if ws_text.contains("\n") && !ws_suffix.contains("\n") {
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if let Some(node) = ws.next_sibling() {
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let start = match ws_prefix.rfind('\n') {
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Some(idx) => ws.range().start() + TextUnit::from((idx + 1) as u32),
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None => node.range().start()
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};
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let end = if root.text().char_at(node.range().end()) == Some('\n') {
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node.range().end() + TextUnit::of_char('\n')
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} else {
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node.range().end()
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};
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return TextRange::from_to(start, end);
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}
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}
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ws.range()
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}
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fn pick_best<'a>(l: SyntaxNodeRef<'a>, r: Syntd[axNodeRef<'a>) -> SyntaxNodeRef<'a> {
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return if priority(r) > priority(l) { r } else { l };
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fn priority(n: SyntaxNodeRef) -> usize {
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match n.kind() {
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WHITESPACE => 0,
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IDENT | SELF_KW | SUPER_KW | CRATE_KW => 2,
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_ => 1,
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}
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}
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}
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fn extend_comments(node: SyntaxNodeRef) -> Option<TextRange> {
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let left = adj_com[ments(node, Direction::Backward);
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let right = adj_comments(node, Direction::Forward);
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if left != right {
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Some(TextRange::from_to(
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left.range().start(),
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right.range().end(),
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))
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} else {
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None
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}
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}
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fn adj_comments(node: SyntaxNodeRef, dir: Direction) -> SyntaxNodeRef {
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let mut res = node;
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for node in siblings(node, dir) {
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match node.kind() {
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COMMENT => res = node,
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WHITESPACE if !node.leaf_text().unwrap().as_str().contains("\n\n") => (),
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_ => break
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}
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}
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res
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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use test_utils::extract_offset;
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fn do_check(before: &str, afters: &[&str]) {
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let (cursor, before) = extract_offset(before);
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let file = File::parse(&before);
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let mut range = TextRange::of
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