rename all things

1 files changed, 480 insertions, 0 deletions

diff --git a/crates/ra_editor/src/completion.rs b/crates/ra_editor/src/completion.rs
new file mode 100644
index 000000000..5000b32a0
--- /dev/null
+++ b/crates/ra_editor/src/completion.rs
@@ -0,0 +1,480 @@
+use std::collections::{HashSet, HashMap};
+
+use ra_syntax::{
+    File, TextUnit, AstNode, SyntaxNodeRef, SyntaxKind::*,
+    ast::{self, LoopBodyOwner, ModuleItemOwner},
+    algo::{
+        ancestors,
+        visit::{visitor, Visitor, visitor_ctx, VisitorCtx},
+    },
+    text_utils::is_subrange,
+};
+
+use {
+    AtomEdit, find_node_at_offset,
+    scope::{FnScopes, ModuleScope},
+};
+
+#[derive(Debug)]
+pub struct CompletionItem {
+    /// What user sees in pop-up
+    pub label: String,
+    /// What string is used for filtering, defaults to label
+    pub lookup: Option<String>,
+    /// What is inserted, defaults to label
+    pub snippet: Option<String>
+}
+
+pub fn scope_completion(file: &File, offset: TextUnit) -> Option<Vec<CompletionItem>> {
+    // Insert a fake ident to get a valid parse tree
+    let file = {
+        let edit = AtomEdit::insert(offset, "intellijRulezz".to_string());
+        file.reparse(&edit)
+    };
+    let mut has_completions = false;
+    let mut res = Vec::new();
+    if let Some(name_ref) = find_node_at_offset::<ast::NameRef>(file.syntax(), offset) {
+        has_completions = true;
+        complete_name_ref(&file, name_ref, &mut res);
+        // special case, `trait T { fn foo(i_am_a_name_ref) {} }`
+        if is_node::<ast::Param>(name_ref.syntax()) {
+            param_completions(name_ref.syntax(), &mut res);
+        }
+    }
+    if let Some(name) = find_node_at_offset::<ast::Name>(file.syntax(), offset) {
+        if is_node::<ast::Param>(name.syntax()) {
+            has_completions = true;
+            param_completions(name.syntax(), &mut res);
+        }
+    }
+    if has_completions {
+        Some(res)
+    } else {
+        None
+    }
+}
+
+fn complete_name_ref(file: &File, name_ref: ast::NameRef, acc: &mut Vec<CompletionItem>) {
+    if !is_node::<ast::Path>(name_ref.syntax()) {
+        return;
+    }
+    let mut visited_fn = false;
+    for node in ancestors(name_ref.syntax()) {
+        if let Some(items) = visitor()
+            .visit::<ast::Root, _>(|it| Some(it.items()))
+            .visit::<ast::Module, _>(|it| Some(it.item_list()?.items()))
+            .accept(node) {
+            if let Some(items) = items {
+                let scope = ModuleScope::new(items);
+                acc.extend(
+                    scope.entries().iter()
+                        .filter(|entry| entry.syntax() != name_ref.syntax())
+                        .map(|entry| CompletionItem {
+                            label: entry.name().to_string(),
+                            lookup: None,
+                            snippet: None,
+                        })
+                );
+            }
+            break;
+
+        } else if !visited_fn {
+            if let Some(fn_def) = ast::FnDef::cast(node) {
+                visited_fn = true;
+                complete_expr_keywords(&file, fn_def, name_ref, acc);
+                let scopes = FnScopes::new(fn_def);
+                complete_fn(name_ref, &scopes, acc);
+            }
+        }
+    }
+}
+
+fn param_completions(ctx: SyntaxNodeRef, acc: &mut Vec<CompletionItem>) {
+    let mut params = HashMap::new();
+    for node in ancestors(ctx) {
+        let _ = visitor_ctx(&mut params)
+            .visit::<ast::Root, _>(process)
+            .visit::<ast::ItemList, _>(process)
+            .accept(node);
+    }
+    params.into_iter()
+        .filter_map(|(label, (count, param))| {
+            let lookup = param.pat()?.syntax().text().to_string();
+            if count < 2 { None } else { Some((label, lookup)) }
+        })
+        .for_each(|(label, lookup)| {
+            acc.push(CompletionItem {
+                label, lookup: Some(lookup), snippet: None
+            })
+        });
+
+    fn process<'a, N: ast::FnDefOwner<'a>>(node: N, params: &mut HashMap<String, (u32, ast::Param<'a>)>) {
+        node.functions()
+            .filter_map(|it| it.param_list())
+            .flat_map(|it| it.params())
+            .for_each(|param| {
+                let text = param.syntax().text().to_string();
+                params.entry(text)
+                      .or_insert((0, param))
+                      .0 += 1;
+            })
+    }
+}
+
+fn is_node<'a, N: AstNode<'a>>(node: SyntaxNodeRef<'a>) -> bool {
+    match ancestors(node).filter_map(N::cast).next() {
+        None => false,
+        Some(n) => n.syntax().range() == node.range(),
+    }
+}
+
+
+fn complete_expr_keywords(file: &File, fn_def: ast::FnDef, name_ref: ast::NameRef, acc: &mut Vec<CompletionItem>) {
+    acc.push(keyword("if", "if $0 {}"));
+    acc.push(keyword("match", "match $0 {}"));
+    acc.push(keyword("while", "while $0 {}"));
+    acc.push(keyword("loop", "loop {$0}"));
+
+    if let Some(off) = name_ref.syntax().range().start().checked_sub(2.into()) {
+        if let Some(if_expr) = find_node_at_offset::<ast::IfExpr>(file.syntax(), off) {
+            if if_expr.syntax().range().end() < name_ref.syntax().range().start() {
+                acc.push(keyword("else", "else {$0}"));
+                acc.push(keyword("else if", "else if $0 {}"));
+            }
+        }
+    }
+    if is_in_loop_body(name_ref) {
+        acc.push(keyword("continue", "continue"));
+        acc.push(keyword("break", "break"));
+    }
+    acc.extend(complete_return(fn_def, name_ref));
+}
+
+fn is_in_loop_body(name_ref: ast::NameRef) -> bool {
+    for node in ancestors(name_ref.syntax()) {
+        if node.kind() == FN_DEF || node.kind() == LAMBDA_EXPR {
+            break;
+        }
+        let loop_body = visitor()
+            .visit::<ast::ForExpr, _>(LoopBodyOwner::loop_body)
+            .visit::<ast::WhileExpr, _>(LoopBodyOwner::loop_body)
+            .visit::<ast::LoopExpr, _>(LoopBodyOwner::loop_body)
+            .accept(node);
+        if let Some(Some(body)) = loop_body {
+            if is_subrange(body.syntax().range(), name_ref.syntax().range()) {
+                return true;
+            }
+        }
+    }
+    false
+}
+
+fn complete_return(fn_def: ast::FnDef, name_ref: ast::NameRef) -> Option<CompletionItem> {
+    // let is_last_in_block = ancestors(name_ref.syntax()).filter_map(ast::Expr::cast)
+    //     .next()
+    //     .and_then(|it| it.syntax().parent())
+    //     .and_then(ast::Block::cast)
+    //     .is_some();
+
+    // if is_last_in_block {
+    //     return None;
+    // }
+
+    let is_stmt = match ancestors(name_ref.syntax()).filter_map(ast::ExprStmt::cast).next() {
+        None => false,
+        Some(expr_stmt) => expr_stmt.syntax().range() == name_ref.syntax().range()
+    };
+    let snip = match (is_stmt, fn_def.ret_type().is_some()) {
+        (true, true) => "return $0;",
+        (true, false) => "return;",
+        (false, true) => "return $0",
+        (false, false) => "return",
+    };
+    Some(keyword("return", snip))
+}
+
+fn keyword(kw: &str, snip: &str) -> CompletionItem {
+    CompletionItem {
+        label: kw.to_string(),
+        lookup: None,
+        snippet: Some(snip.to_string()),
+    }
+}
+
+fn complete_fn(name_ref: ast::NameRef, scopes: &FnScopes, acc: &mut Vec<CompletionItem>) {
+    let mut shadowed = HashSet::new();
+    acc.extend(
+        scopes.scope_chain(name_ref.syntax())
+            .flat_map(|scope| scopes.entries(scope).iter())
+            .filter(|entry| shadowed.insert(entry.name()))
+            .map(|entry| CompletionItem {
+                label: entry.name().to_string(),
+                lookup: None,
+                snippet: None,
+            })
+    );
+    if scopes.self_param.is_some() {
+        acc.push(CompletionItem {
+            label: "self".to_string(),
+            lookup: None,
+            snippet: None,
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use test_utils::{assert_eq_dbg, extract_offset};
+
+    fn check_scope_completion(code: &str, expected_completions: &str) {
+        let (off, code) = extract_offset(&code);
+        let file = File::parse(&code);
+        let completions = scope_completion(&file, off)
+            .unwrap()
+            .into_iter()
+            .filter(|c| c.snippet.is_none())
+            .collect::<Vec<_>>();
+        assert_eq_dbg(expected_completions, &completions);
+    }
+
+    fn check_snippet_completion(code: &str, expected_completions: &str) {
+        let (off, code) = extract_offset(&code);
+        let file = File::parse(&code);
+        let completions = scope_completion(&file, off)
+            .unwrap()
+            .into_iter()
+            .filter(|c| c.snippet.is_some())
+            .collect::<Vec<_>>();
+        assert_eq_dbg(expected_completions, &completions);
+    }
+
+    #[test]
+    fn test_completion_let_scope() {
+        check_scope_completion(r"
+            fn quux(x: i32) {
+                let y = 92;
+                1 + <|>;
+                let z = ();
+            }
+            ", r#"[CompletionItem { label: "y", lookup: None, snippet: None },
+                   CompletionItem { label: "x", lookup: None, snippet: None },
+                   CompletionItem { label: "quux", lookup: None, snippet: None }]"#);
+    }
+
+    #[test]
+    fn test_completion_if_let_scope() {
+        check_scope_completion(r"
+            fn quux() {
+                if let Some(x) = foo() {
+                    let y = 92;
+                };
+                if let Some(a) = bar() {
+                    let b = 62;
+                    1 + <|>
+                }
+            }
+            ", r#"[CompletionItem { label: "b", lookup: None, snippet: None },
+                   CompletionItem { label: "a", lookup: None, snippet: None },
+                   CompletionItem { label: "quux", lookup: None, snippet: None }]"#);
+    }
+
+    #[test]
+    fn test_completion_for_scope() {
+        check_scope_completion(r"
+            fn quux() {
+                for x in &[1, 2, 3] {
+                    <|>
+                }
+            }
+            ", r#"[CompletionItem { label: "x", lookup: None, snippet: None },
+                   CompletionItem { label: "quux", lookup: None, snippet: None }]"#);
+    }
+
+    #[test]
+    fn test_completion_mod_scope() {
+        check_scope_completion(r"
+            struct Foo;
+            enum Baz {}
+            fn quux() {
+                <|>
+            }
+            ", r#"[CompletionItem { label: "Foo", lookup: None, snippet: None },
+                   CompletionItem { label: "Baz", lookup: None, snippet: None },
+                   CompletionItem { label: "quux", lookup: None, snippet: None }]"#);
+    }
+
+    #[test]
+    fn test_completion_mod_scope_no_self_use() {
+        check_scope_completion(r"
+            use foo<|>;
+            ", r#"[]"#);
+    }
+
+    #[test]
+    fn test_completion_mod_scope_nested() {
+        check_scope_completion(r"
+            struct Foo;
+            mod m {
+                struct Bar;
+                fn quux() { <|> }
+            }
+            ", r#"[CompletionItem { label: "Bar", lookup: None, snippet: None },
+                   CompletionItem { label: "quux", lookup: None, snippet: None }]"#);
+    }
+
+    #[test]
+    fn test_complete_type() {
+        check_scope_completion(r"
+            struct Foo;
+            fn x() -> <|>
+        ", r#"[CompletionItem { label: "Foo", lookup: None, snippet: None },
+               CompletionItem { label: "x", lookup: None, snippet: None }]"#)
+    }
+
+    #[test]
+    fn test_complete_shadowing() {
+        check_scope_completion(r"
+            fn foo() -> {
+                let bar = 92;
+                {
+                    let bar = 62;
+                    <|>
+                }
+            }
+        ", r#"[CompletionItem { label: "bar", lookup: None, snippet: None },
+               CompletionItem { label: "foo", lookup: None, snippet: None }]"#)
+    }
+
+    #[test]
+    fn test_complete_self() {
+        check_scope_completion(r"
+            impl S { fn foo(&self) { <|> } }
+        ", r#"[CompletionItem { label: "self", lookup: None, snippet: None }]"#)
+    }
+
+    #[test]
+    fn test_completion_kewords() {
+        check_snippet_completion(r"
+            fn quux() {
+                <|>
+            }
+            ", r#"[CompletionItem { label: "if", lookup: None, snippet: Some("if $0 {}") },
+                   CompletionItem { label: "match", lookup: None, snippet: Some("match $0 {}") },
+                   CompletionItem { label: "while", lookup: None, snippet: Some("while $0 {}") },
+                   CompletionItem { label: "loop", lookup: None, snippet: Some("loop {$0}") },
+                   CompletionItem { label: "return", lookup: None, snippet: Some("return") }]"#);
+    }
+
+    #[test]
+    fn test_completion_else() {
+        check_snippet_completion(r"
+            fn quux() {
+                if true {
+                    ()
+                } <|>
+            }
+            ", r#"[CompletionItem { label: "if", lookup: None, snippet: Some("if $0 {}") },
+                   CompletionItem { label: "match", lookup: None, snippet: Some("match $0 {}") },
+                   CompletionItem { label: "while", lookup: None, snippet: Some("while $0 {}") },
+                   CompletionItem { label: "loop", lookup: None, snippet: Some("loop {$0}") },
+                   CompletionItem { label: "else", lookup: None, snippet: Some("else {$0}") },
+                   CompletionItem { label: "else if", lookup: None, snippet: Some("else if $0 {}") },
+                   CompletionItem { label: "return", lookup: None, snippet: Some("return") }]"#);
+    }
+
+    #[test]
+    fn test_completion_return_value() {
+        check_snippet_completion(r"
+            fn quux() -> i32 {
+                <|>
+                92
+            }
+            ", r#"[CompletionItem { label: "if", lookup: None, snippet: Some("if $0 {}") },
+                   CompletionItem { label: "match", lookup: None, snippet: Some("match $0 {}") },
+                   CompletionItem { label: "while", lookup: None, snippet: Some("while $0 {}") },
+                   CompletionItem { label: "loop", lookup: None, snippet: Some("loop {$0}") },
+                   CompletionItem { label: "return", lookup: None, snippet: Some("return $0;") }]"#);
+        check_snippet_completion(r"
+            fn quux() {
+                <|>
+                92
+            }
+            ", r#"[CompletionItem { label: "if", lookup: None, snippet: Some("if $0 {}") },
+                   CompletionItem { label: "match", lookup: None, snippet: Some("match $0 {}") },
+                   CompletionItem { label: "while", lookup: None, snippet: Some("while $0 {}") },
+                   CompletionItem { label: "loop", lookup: None, snippet: Some("loop {$0}") },
+                   CompletionItem { label: "return", lookup: None, snippet: Some("return;") }]"#);
+    }
+
+    #[test]
+    fn test_completion_return_no_stmt() {
+        check_snippet_completion(r"
+            fn quux() -> i32 {
+                match () {
+                    () => <|>
+                }
+            }
+            ", r#"[CompletionItem { label: "if", lookup: None, snippet: Some("if $0 {}") },
+                   CompletionItem { label: "match", lookup: None, snippet: Some("match $0 {}") },
+                   CompletionItem { label: "while", lookup: None, snippet: Some("while $0 {}") },
+                   CompletionItem { label: "loop", lookup: None, snippet: Some("loop {$0}") },
+                   CompletionItem { label: "return", lookup: None, snippet: Some("return $0") }]"#);
+    }
+
+    #[test]
+    fn test_continue_break_completion() {
+        check_snippet_completion(r"
+            fn quux() -> i32 {
+                loop { <|> }
+            }
+            ", r#"[CompletionItem { label: "if", lookup: None, snippet: Some("if $0 {}") },
+                   CompletionItem { label: "match", lookup: None, snippet: Some("match $0 {}") },
+                   CompletionItem { label: "while", lookup: None, snippet: Some("while $0 {}") },
+                   CompletionItem { label: "loop", lookup: None, snippet: Some("loop {$0}") },
+                   CompletionItem { label: "continue", lookup: None, snippet: Some("continue") },
+                   CompletionItem { label: "break", lookup: None, snippet: Some("break") },
+                   CompletionItem { label: "return", lookup: None, snippet: Some("return $0") }]"#);
+        check_snippet_completion(r"
+            fn quux() -> i32 {
+                loop { || { <|> } }
+            }
+            ", r#"[CompletionItem { label: "if", lookup: None, snippet: Some("if $0 {}") },
+                   CompletionItem { label: "match", lookup: None, snippet: Some("match $0 {}") },
+                   CompletionItem { label: "while", lookup: None, snippet: Some("while $0 {}") },
+                   CompletionItem { label: "loop", lookup: None, snippet: Some("loop {$0}") },
+                   CompletionItem { label: "return", lookup: None, snippet: Some("return $0") }]"#);
+    }
+
+    #[test]
+    fn test_param_completion_last_param() {
+        check_scope_completion(r"
+            fn foo(file_id: FileId) {}
+            fn bar(file_id: FileId) {}
+            fn baz(file<|>) {}
+        ", r#"[CompletionItem { label: "file_id: FileId", lookup: Some("file_id"), snippet: None }]"#);
+    }
+
+    #[test]
+    fn test_param_completion_nth_param() {
+        check_scope_completion(r"
+            fn foo(file_id: FileId) {}
+            fn bar(file_id: FileId) {}
+            fn baz(file<|>, x: i32) {}
+        ", r#"[CompletionItem { label: "file_id: FileId", lookup: Some("file_id"), snippet: None }]"#);
+    }
+
+    #[test]
+    fn test_param_completion_trait_param() {
+        check_scope_completion(r"
+            pub(crate) trait SourceRoot {
+                pub fn contains(&self, file_id: FileId) -> bool;
+                pub fn module_map(&self) -> &ModuleMap;
+                pub fn lines(&self, file_id: FileId) -> &LineIndex;
+                pub fn syntax(&self, file<|>)
+            }
+        ", r#"[CompletionItem { label: "self", lookup: None, snippet: None },
+               CompletionItem { label: "SourceRoot", lookup: None, snippet: None },
+               CompletionItem { label: "file_id: FileId", lookup: Some("file_id"), snippet: None }]"#);
+    }
+}