1 files changed, 3 insertions, 184 deletions

diff --git a/crates/libeditor/src/completion.rs b/crates/libeditor/src/completion.rs
index 69c039e83..242a3a434 100644
--- a/crates/libeditor/src/completion.rs
+++ b/crates/libeditor/src/completion.rs
@@ -1,20 +1,14 @@
-use std::{
-    fmt,
-    collections::HashMap,
-};
-
 use libsyntax2::{
-    File, TextUnit, AstNode, SyntaxNodeRef, SyntaxNode, SmolStr,
-    ast::{self, NameOwner},
+    File, TextUnit, AstNode,
+    ast::self,
     algo::{
         ancestors,
-        walk::preorder,
-        generate,
     },
 };
 
 use {
     AtomEdit, find_node_at_offset,
+    scope::{FnScopes, compute_scopes},
 };
 
 #[derive(Debug)]
@@ -43,178 +37,3 @@ fn complete(name_ref: ast::NameRef, scopes: &FnScopes) -> Vec<CompletionItem> {
         })
         .collect()
 }
-
-fn compute_scopes(fn_def: ast::FnDef) -> FnScopes {
-    let mut scopes = FnScopes::new();
-    let root = scopes.root_scope();
-    fn_def.param_list().into_iter()
-        .flat_map(|it| it.params())
-        .filter_map(|it| it.pat())
-        .for_each(|it| scopes.add_bindings(root, it));
-
-    if let Some(body) = fn_def.body() {
-        compute_block_scopes(body, &mut scopes, root)
-    }
-    scopes
-}
-
-fn compute_block_scopes(block: ast::Block, scopes: &mut FnScopes, mut scope: ScopeId) {
-    for stmt in block.statements() {
-        match stmt {
-            ast::Stmt::LetStmt(stmt) => {
-                scope = scopes.new_scope(scope);
-                if let Some(pat) = stmt.pat() {
-                    scopes.add_bindings(scope, pat);
-                }
-                if let Some(expr) = stmt.initializer() {
-                    scopes.set_scope(expr.syntax(), scope)
-                }
-            }
-            ast::Stmt::ExprStmt(expr_stmt) => {
-                if let Some(expr) = expr_stmt.expr() {
-                    scopes.set_scope(expr.syntax(), scope);
-                    compute_expr_scopes(expr, scopes, scope);
-                }
-            }
-        }
-    }
-    if let Some(expr) = block.expr() {
-        scopes.set_scope(expr.syntax(), scope);
-        compute_expr_scopes(expr, scopes, scope);
-    }
-}
-
-fn compute_expr_scopes(expr: ast::Expr, scopes: &mut FnScopes, scope: ScopeId) {
-    match expr {
-        ast::Expr::IfExpr(e) => {
-            let cond_scope = e.condition().and_then(|cond| {
-                compute_cond_scopes(cond, scopes, scope)
-            });
-            if let Some(block) = e.then_branch() {
-                compute_block_scopes(block, scopes, cond_scope.unwrap_or(scope));
-            }
-            if let Some(block) = e.else_branch() {
-                compute_block_scopes(block, scopes, scope);
-            }
-        },
-        ast::Expr::WhileExpr(e) => {
-            let cond_scope = e.condition().and_then(|cond| {
-                compute_cond_scopes(cond, scopes, scope)
-            });
-            if let Some(block) = e.body() {
-                compute_block_scopes(block, scopes, cond_scope.unwrap_or(scope));
-            }
-        },
-        ast::Expr::BlockExpr(e) => {
-            if let Some(block) = e.block() {
-                compute_block_scopes(block, scopes, scope);
-            }
-        }
-        // ForExpr(e) => TODO,
-        _ => {
-            expr.syntax().children()
-                .filter_map(ast::Expr::cast)
-                .for_each(|expr| compute_expr_scopes(expr, scopes, scope))
-        }
-    };
-
-    fn compute_cond_scopes(cond: ast::Condition, scopes: &mut FnScopes, scope: ScopeId) -> Option<ScopeId> {
-        if let Some(expr) = cond.expr() {
-            compute_expr_scopes(expr, scopes, scope);
-        }
-        if let Some(pat) = cond.pat() {
-            let s = scopes.new_scope(scope);
-            scopes.add_bindings(s, pat);
-            Some(s)
-        } else {
-            None
-        }
-    }
-}
-
-type ScopeId = usize;
-
-#[derive(Debug)]
-struct FnScopes {
-    scopes: Vec<ScopeData>,
-    scope_for: HashMap<SyntaxNode, ScopeId>,
-}
-
-impl FnScopes {
-    fn new() -> FnScopes {
-        FnScopes {
-            scopes: vec![],
-            scope_for: HashMap::new(),
-        }
-    }
-    fn root_scope(&mut self) -> ScopeId {
-        let res = self.scopes.len();
-        self.scopes.push(ScopeData { parent: None, entries: vec![] });
-        res
-    }
-    fn new_scope(&mut self, parent: ScopeId) -> ScopeId {
-        let res = self.scopes.len();
-        self.scopes.push(ScopeData { parent: Some(parent), entries: vec![] });
-        res
-    }
-    fn add_bindings(&mut self, scope: ScopeId, pat: ast::Pat) {
-        let entries = preorder(pat.syntax())
-            .filter_map(ast::BindPat::cast)
-            .filter_map(ScopeEntry::new);
-        self.scopes[scope].entries.extend(entries);
-    }
-    fn set_scope(&mut self, node: SyntaxNodeRef, scope: ScopeId) {
-        self.scope_for.insert(node.owned(), scope);
-    }
-    fn entries(&self, scope: ScopeId) -> &[ScopeEntry] {
-        &self.scopes[scope].entries
-    }
-    fn scope_for(&self, node: SyntaxNodeRef) -> Option<ScopeId> {
-        ancestors(node)
-            .filter_map(|it| self.scope_for.get(&it.owned()).map(|&scope| scope))
-            .next()
-    }
-    fn scope_chain<'a>(&'a self, node: SyntaxNodeRef) -> impl Iterator<Item=ScopeId> + 'a {
-        generate(self.scope_for(node), move |&scope| self.scopes[scope].parent)
-    }
-}
-
-#[derive(Debug)]
-struct ScopeData {
-    parent: Option<ScopeId>,
-    entries: Vec<ScopeEntry>
-}
-
-struct ScopeEntry {
-    syntax: SyntaxNode
-}
-
-impl ScopeEntry {
-    fn new(pat: ast::BindPat) -> Option<ScopeEntry> {
-        if pat.name().is_some() {
-            Some(ScopeEntry { syntax: pat.syntax().owned() })
-        } else {
-            None
-        }
-    }
-
-    fn name(&self) -> SmolStr {
-        self.ast().name()
-            .unwrap()
-            .text()
-    }
-
-    fn ast(&self) -> ast::BindPat {
-        ast::BindPat::cast(self.syntax.borrowed())
-            .unwrap()
-    }
-}
-
-impl fmt::Debug for ScopeEntry {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        f.debug_struct("ScopeEntry")
-         .field("name", &self.name())
-         .field("syntax", &self.syntax)
-         .finish()
-    }
-}