rename ra_editor -> ra_ide_api_light

1 files changed, 297 insertions, 0 deletions

diff --git a/crates/ra_ide_api_light/src/folding_ranges.rs b/crates/ra_ide_api_light/src/folding_ranges.rs
new file mode 100644
index 000000000..6f3106889
--- /dev/null
+++ b/crates/ra_ide_api_light/src/folding_ranges.rs
@@ -0,0 +1,297 @@
+use rustc_hash::FxHashSet;
+
+use ra_syntax::{
+    ast, AstNode, Direction, SourceFile, SyntaxNode, TextRange,
+    SyntaxKind::{self, *},
+};
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum FoldKind {
+    Comment,
+    Imports,
+    Block,
+}
+
+#[derive(Debug)]
+pub struct Fold {
+    pub range: TextRange,
+    pub kind: FoldKind,
+}
+
+pub fn folding_ranges(file: &SourceFile) -> Vec<Fold> {
+    let mut res = vec![];
+    let mut visited_comments = FxHashSet::default();
+    let mut visited_imports = FxHashSet::default();
+
+    for node in file.syntax().descendants() {
+        // Fold items that span multiple lines
+        if let Some(kind) = fold_kind(node.kind()) {
+            if has_newline(node) {
+                res.push(Fold {
+                    range: node.range(),
+                    kind,
+                });
+            }
+        }
+
+        // Fold groups of comments
+        if node.kind() == COMMENT && !visited_comments.contains(&node) {
+            if let Some(range) = contiguous_range_for_comment(node, &mut visited_comments) {
+                res.push(Fold {
+                    range,
+                    kind: FoldKind::Comment,
+                })
+            }
+        }
+
+        // Fold groups of imports
+        if node.kind() == USE_ITEM && !visited_imports.contains(&node) {
+            if let Some(range) = contiguous_range_for_group(node, &mut visited_imports) {
+                res.push(Fold {
+                    range,
+                    kind: FoldKind::Imports,
+                })
+            }
+        }
+    }
+
+    res
+}
+
+fn fold_kind(kind: SyntaxKind) -> Option<FoldKind> {
+    match kind {
+        COMMENT => Some(FoldKind::Comment),
+        USE_ITEM => Some(FoldKind::Imports),
+        NAMED_FIELD_DEF_LIST | FIELD_PAT_LIST | ITEM_LIST | EXTERN_ITEM_LIST | USE_TREE_LIST
+        | BLOCK | ENUM_VARIANT_LIST => Some(FoldKind::Block),
+        _ => None,
+    }
+}
+
+fn has_newline(node: &SyntaxNode) -> bool {
+    for descendant in node.descendants() {
+        if let Some(ws) = ast::Whitespace::cast(descendant) {
+            if ws.has_newlines() {
+                return true;
+            }
+        } else if let Some(comment) = ast::Comment::cast(descendant) {
+            if comment.has_newlines() {
+                return true;
+            }
+        }
+    }
+
+    false
+}
+
+fn contiguous_range_for_group<'a>(
+    first: &'a SyntaxNode,
+    visited: &mut FxHashSet<&'a SyntaxNode>,
+) -> Option<TextRange> {
+    visited.insert(first);
+
+    let mut last = first;
+    for node in first.siblings(Direction::Next) {
+        if let Some(ws) = ast::Whitespace::cast(node) {
+            // There is a blank line, which means that the group ends here
+            if ws.count_newlines_lazy().take(2).count() == 2 {
+                break;
+            }
+
+            // Ignore whitespace without blank lines
+            continue;
+        }
+
+        // Stop if we find a node that doesn't belong to the group
+        if node.kind() != first.kind() {
+            break;
+        }
+
+        visited.insert(node);
+        last = node;
+    }
+
+    if first != last {
+        Some(TextRange::from_to(
+            first.range().start(),
+            last.range().end(),
+        ))
+    } else {
+        // The group consists of only one element, therefore it cannot be folded
+        None
+    }
+}
+
+fn contiguous_range_for_comment<'a>(
+    first: &'a SyntaxNode,
+    visited: &mut FxHashSet<&'a SyntaxNode>,
+) -> Option<TextRange> {
+    visited.insert(first);
+
+    // Only fold comments of the same flavor
+    let group_flavor = ast::Comment::cast(first)?.flavor();
+
+    let mut last = first;
+    for node in first.siblings(Direction::Next) {
+        if let Some(ws) = ast::Whitespace::cast(node) {
+            // There is a blank line, which means the group ends here
+            if ws.count_newlines_lazy().take(2).count() == 2 {
+                break;
+            }
+
+            // Ignore whitespace without blank lines
+            continue;
+        }
+
+        match ast::Comment::cast(node) {
+            Some(next_comment) if next_comment.flavor() == group_flavor => {
+                visited.insert(node);
+                last = node;
+            }
+            // The comment group ends because either:
+            // * An element of a different kind was reached
+            // * A comment of a different flavor was reached
+            _ => break,
+        }
+    }
+
+    if first != last {
+        Some(TextRange::from_to(
+            first.range().start(),
+            last.range().end(),
+        ))
+    } else {
+        // The group consists of only one element, therefore it cannot be folded
+        None
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use test_utils::extract_ranges;
+
+    fn do_check(text: &str, fold_kinds: &[FoldKind]) {
+        let (ranges, text) = extract_ranges(text, "fold");
+        let file = SourceFile::parse(&text);
+        let folds = folding_ranges(&file);
+
+        assert_eq!(
+            folds.len(),
+            ranges.len(),
+            "The amount of folds is different than the expected amount"
+        );
+        assert_eq!(
+            folds.len(),
+            fold_kinds.len(),
+            "The amount of fold kinds is different than the expected amount"
+        );
+        for ((fold, range), fold_kind) in folds
+            .into_iter()
+            .zip(ranges.into_iter())
+            .zip(fold_kinds.into_iter())
+        {
+            assert_eq!(fold.range.start(), range.start());
+            assert_eq!(fold.range.end(), range.end());
+            assert_eq!(&fold.kind, fold_kind);
+        }
+    }
+
+    #[test]
+    fn test_fold_comments() {
+        let text = r#"
+<fold>// Hello
+// this is a multiline
+// comment
+//</fold>
+
+// But this is not
+
+fn main() <fold>{
+    <fold>// We should
+    // also
+    // fold
+    // this one.</fold>
+    <fold>//! But this one is different
+    //! because it has another flavor</fold>
+    <fold>/* As does this
+    multiline comment */</fold>
+}</fold>"#;
+
+        let fold_kinds = &[
+            FoldKind::Comment,
+            FoldKind::Block,
+            FoldKind::Comment,
+            FoldKind::Comment,
+            FoldKind::Comment,
+        ];
+        do_check(text, fold_kinds);
+    }
+
+    #[test]
+    fn test_fold_imports() {
+        let text = r#"
+<fold>use std::<fold>{
+    str,
+    vec,
+    io as iop
+}</fold>;</fold>
+
+fn main() <fold>{
+}</fold>"#;
+
+        let folds = &[FoldKind::Imports, FoldKind::Block, FoldKind::Block];
+        do_check(text, folds);
+    }
+
+    #[test]
+    fn test_fold_import_groups() {
+        let text = r#"
+<fold>use std::str;
+use std::vec;
+use std::io as iop;</fold>
+
+<fold>use std::mem;
+use std::f64;</fold>
+
+use std::collections::HashMap;
+// Some random comment
+use std::collections::VecDeque;
+
+fn main() <fold>{
+}</fold>"#;
+
+        let folds = &[FoldKind::Imports, FoldKind::Imports, FoldKind::Block];
+        do_check(text, folds);
+    }
+
+    #[test]
+    fn test_fold_import_and_groups() {
+        let text = r#"
+<fold>use std::str;
+use std::vec;
+use std::io as iop;</fold>
+
+<fold>use std::mem;
+use std::f64;</fold>
+
+<fold>use std::collections::<fold>{
+    HashMap,
+    VecDeque,
+}</fold>;</fold>
+// Some random comment
+
+fn main() <fold>{
+}</fold>"#;
+
+        let folds = &[
+            FoldKind::Imports,
+            FoldKind::Imports,
+            FoldKind::Imports,
+            FoldKind::Block,
+            FoldKind::Block,
+        ];
+        do_check(text, folds);
+    }
+
+}