local code completion suggestions

pkg/analysis_services/lib/src/completion/local_computer.dart

+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library services.completion.computer.dart.local;
+
+import 'dart:async';
+
+import 'package:analysis_services/completion/completion_computer.dart';
+import 'package:analysis_services/completion/completion_suggestion.dart';
+import 'package:analyzer/src/generated/ast.dart';
+
+/**
+ * A computer for calculating class and top level variable

[scheglov, 2014/08/10 21:45:14]

You probably want to update the comment.

[danrubel, 2014/08/11 03:04:38]

Done.

+ * `completion.getSuggestions` request results
+ */
+class LocalComputer extends CompletionComputer {
+
+  @override
+  bool computeFast(CompilationUnit unit,
+      List<CompletionSuggestion> suggestions) {
+
+    // Find the specific child [AstNode] that contains the completion offset
+    // and collect suggestions starting with that node
+    AstNode node = new NodeLocator.con1(offset).searchWithin(unit);
+    if (node != null) {
+      node.accept(new _LocalVisitor(offset, suggestions));
+    }
+
+    // If the unit is not a part and does not reference any parts
+    // then work is complete
+    return !unit.directives.any(
+        (d) => d is PartOfDirective || d is PartDirective);
+  }
+
+  @override
+  Future<bool> computeFull(CompilationUnit unit,
+      List<CompletionSuggestion> suggestions) {
+    // TODO: implement computeFull
+    // include results from part files that are included in the library
+    return new Future.value(false);
+  }
+}
+
+/**
+ * A visitor for collecting suggestions from the most specific child [AstNode]
+ * that contains the completion offset to the [CompilationUnit].
+ */
+class _LocalVisitor extends GeneralizingAstVisitor<dynamic> {
+  final int offset;
+  final List<CompletionSuggestion> suggestions;
+
+  _LocalVisitor(this.offset, this.suggestions);
+
+  void addSuggestion(SimpleIdentifier id, CompletionSuggestionKind kind) {
+    if (id != null) {
+      String completion = id.name;
+      if (completion != null && completion.length > 0) {
+        suggestions.add(
+            new CompletionSuggestion(
+                kind,
+                CompletionRelevance.DEFAULT,
+                completion,
+                completion.length,
+                0,
+                false,
+                false));
+      }
+    }
+  }
+
+  void addSuggestions(VariableDeclarationList variables,
+      CompletionSuggestionKind kind) {
+    variables.variables.forEach((VariableDeclaration v) {

[scheglov, 2014/08/10 21:45:14]

Could you use full words, not just single characters?

[danrubel, 2014/08/11 03:04:38]

Good point. I have cleaned several places in this file.

+      addSuggestion(v.name, kind);
+    });
+  }
+
+  visitBlock(Block node) {
+    node.statements.forEach((Statement s) {
+      if (s.offset < offset) {

[scheglov, 2014/08/10 21:45:14]

Not quite so easy.

This code is valid and would be nice to propose "a" in "b = 2 + ^".

main() {
  int a = 1, b = 2 + a;
  print(a);
  print(b);
}

Maybe worth to add TODO.

[danrubel, 2014/08/11 03:04:38]

Good point. https://codereview.chromium.org/459743002/

+        if (s is LabeledStatement) {
+          s.labels.forEach((l) {
+            l.label;

[scheglov, 2014/08/10 21:45:15]

I don't think this statement is useful.

[danrubel, 2014/08/11 03:04:38]

Removed and commented out following line as it is not yet supported.

+            addSuggestion(l.label, CompletionSuggestionKind.LABEL);
+          });
+        } else if (s is VariableDeclarationStatement) {
+          addSuggestions(s.variables, CompletionSuggestionKind.VARIABLE);
+        }
+      }
+    });
+    visitNode(node);
+  }
+
+  visitCatchClause(CatchClause node) {
+    addSuggestion(node.exceptionParameter, CompletionSuggestionKind.PARAMETER);
+    addSuggestion(node.stackTraceParameter, CompletionSuggestionKind.PARAMETER);
+    visitNode(node);
+  }
+
+  visitClassDeclaration(ClassDeclaration node) {
+    node.members.forEach((ClassMember m) {
+      if (m is FieldDeclaration) {
+        addSuggestions(m.fields, CompletionSuggestionKind.FIELD);
+      } else if (m is MethodDeclaration) {
+        addSuggestion(m.name, CompletionSuggestionKind.METHOD_NAME);
+      }
+    });
+    visitNode(node);
+  }
+
+  visitCompilationUnit(CompilationUnit node) {
+    node.directives.forEach((Directive d) {
+      if (d is ImportDirective) {
+        addSuggestion(d.prefix, CompletionSuggestionKind.LIBRARY_PREFIX);
+      }
+    });
+    node.declarations.forEach((Declaration d) {
+      if (d is ClassDeclaration) {
+        addSuggestion(d.name, CompletionSuggestionKind.CLASS);
+      } else if (d is EnumDeclaration) {
+        addSuggestion(d.name, CompletionSuggestionKind.ENUM);
+      } else if (d is FunctionDeclaration) {
+        addSuggestion(d.name, CompletionSuggestionKind.FUNCTION);
+      } else if (d is TopLevelVariableDeclaration) {
+        addSuggestions(
+            d.variables,
+            CompletionSuggestionKind.TOP_LEVEL_VARIABLE);
+      } else if (d is ClassTypeAlias) {
+        addSuggestion(d.name, CompletionSuggestionKind.CLASS_ALIAS);
+      } else if (d is FunctionTypeAlias) {
+        addSuggestion(d.name, CompletionSuggestionKind.FUNCTION_TYPE_ALIAS);
+      }
+    });
+  }
+
+  visitForEachStatement(ForEachStatement node) {
+    addSuggestion(node.identifier, CompletionSuggestionKind.VARIABLE);
+    visitNode(node);
+  }
+
+  visitForStatement(ForStatement node) {
+    addSuggestions(node.variables, CompletionSuggestionKind.VARIABLE);
+    visitNode(node);
+  }
+
+  visitFunctionDeclaration(FunctionDeclaration node) {
+    addSuggestion(node.name, CompletionSuggestionKind.FUNCTION);
+    visitNode(node);
+  }
+
+  visitFunctionExpression(FunctionExpression node) {
+    node.parameters.parameters.forEach((FormalParameter p) {
+      addSuggestion(p.identifier, CompletionSuggestionKind.PARAMETER);
+    });
+    visitNode(node);
+  }
+
+  visitMethodDeclaration(MethodDeclaration node) {
+    node.parameters.parameters.forEach((FormalParameter p) {
+      if (p.identifier != null) {
+        addSuggestion(p.identifier, CompletionSuggestionKind.PARAMETER);
+      }
+    });
+    visitNode(node);
+  }
+
+  visitNode(AstNode node) {
+    node.parent.accept(this);
+  }
+}