first cut argument list completion suggestions

pkg/analysis_server/lib/src/services/completion/local_declaration_visitor.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.Declaration.visitor;
+
+import 'package:analysis_server/src/services/completion/suggestion_builder.dart';
+import 'package:analyzer/src/generated/ast.dart';
+import 'package:analyzer/src/generated/scanner.dart';
+
+/**
+ * `LocalDeclarationCollector` visits an [AstNode] and its parent recursively
+ * along with any declarations in those nodes. Setting the [finished] flag
+ * `true` will prevent further recursion.
+ */
+abstract class LocalDeclarationVisitor extends GeneralizingAstVisitor<bool> {
+
+  static final TypeName STACKTRACE_TYPE = new TypeName(
+      new SimpleIdentifier(new StringToken(TokenType.IDENTIFIER, 'StackTrace', 0)),
+      null);
+
+  final int offset;
+  bool finished = false;
+
+  LocalDeclarationVisitor(this.offset);
+
+  void declaredClass(ClassDeclaration declaration);
+
+  void declaredClassTypeAlias(ClassTypeAlias declaration);
+
+  void declaredField(FieldDeclaration fieldDecl, VariableDeclaration varDecl);
+
+  void declaredFunction(FunctionDeclaration declaration);
+
+  void declaredFunctionTypeAlias(FunctionTypeAlias declaration);
+
+  void declaredLabel(Label label);
+
+  void declaredLocalVar(SimpleIdentifier name, TypeName type);
+
+  void declaredMethod(MethodDeclaration declaration);
+
+  void declaredParam(SimpleIdentifier name, TypeName type);
+
+  void declaredTopLevelVar(VariableDeclarationList varList,
+      VariableDeclaration varDecl);
+
+  @override
+  bool visitBlock(Block node) {
+    node.statements.forEach((Statement stmt) {
+      if (stmt.offset < offset) {
+        if (stmt is LabeledStatement) {
+          stmt.labels.forEach((Label label) {
+            declaredLabel(label);
+          });
+        } else if (stmt is VariableDeclarationStatement) {
+          VariableDeclarationList varList = stmt.variables;
+          if (varList != null) {
+            varList.variables.forEach((VariableDeclaration varDecl) {
+              if (varDecl.end < offset) {
+                declaredLocalVar(varDecl.name, varList.type);
+              }
+            });
+          }
+        }
+      }
+    });
+    return visitNode(node);
+  }
+
+  @override
+  bool visitCatchClause(CatchClause node) {
+    SimpleIdentifier param = node.exceptionParameter;
+    if (param != null) {
+      declaredParam(param, node.exceptionType);
+    }
+    param = node.stackTraceParameter;
+    if (param != null) {
+      declaredParam(param, STACKTRACE_TYPE);
+    }
+    return visitNode(node);
+  }
+
+  @override
+  bool visitClassDeclaration(ClassDeclaration node) {
+    _visitClassDeclarationMembers(node);
+    visitInheritedTypes(node, (ClassDeclaration classNode) {
+      _visitClassDeclarationMembers(classNode);
+    }, (String typeName) {
+      // ignored
+    });
+    return visitNode(node);
+  }
+
+  @override
+  bool visitCompilationUnit(CompilationUnit node) {
+    node.declarations.forEach((Declaration declaration) {
+      if (declaration is ClassDeclaration) {
+        declaredClass(declaration);
+      } else if (declaration is EnumDeclaration) {
+        // TODO (danrubel) enum support
+//        declaredEnum(........)
+      } else if (declaration is FunctionDeclaration) {
+        declaredFunction(declaration);
+      } else if (declaration is TopLevelVariableDeclaration) {
+        var varList = declaration.variables;
+        if (varList != null) {
+          varList.variables.forEach((VariableDeclaration varDecl) {
+            declaredTopLevelVar(varList, varDecl);
+          });
+        }
+      } else if (declaration is ClassTypeAlias) {
+        declaredClassTypeAlias(declaration);
+      } else if (declaration is FunctionTypeAlias) {
+        declaredFunctionTypeAlias(declaration);
+      }
+    });
+    return finished;
+  }
+
+  @override
+  bool visitExpressionStatement(ExpressionStatement node) {
+    Expression expression = node.expression;
+    if (expression is SimpleIdentifier) {
+      if (expression.end < offset) {
+        return finished;
+      }
+    }
+    return visitNode(node);
+  }
+
+  @override
+  bool visitForEachStatement(ForEachStatement node) {
+    SimpleIdentifier id;
+    TypeName type;
+    DeclaredIdentifier loopVar = node.loopVariable;
+    if (loopVar != null) {
+      id = loopVar.identifier;
+      type = loopVar.type;
+    } else {
+      id = node.identifier;
+      type = null;
+    }
+    declaredLocalVar(id, type);
+    return visitNode(node);
+  }
+
+  @override
+  bool visitForStatement(ForStatement node) {
+    VariableDeclarationList varList = node.variables;
+    if (varList != null) {
+      varList.variables.forEach((VariableDeclaration varDecl) {
+        declaredLocalVar(varDecl.name, varList.type);
+      });
+    }
+    return visitNode(node);
+  }
+
+  @override
+  bool visitFunctionDeclaration(FunctionDeclaration node) {
+    // declaredFunction is called by the compilation unit containing it
+    return visitNode(node);
+  }
+
+  @override
+  bool visitFunctionExpression(FunctionExpression node) {
+    _visitParamList(node.parameters);
+    return visitNode(node);
+  }
+
+  @override
+  bool visitInterpolationExpression(InterpolationExpression node) {
+    return visitNode(node);
+  }
+
+  @override
+  bool visitMethodDeclaration(MethodDeclaration node) {
+    _visitParamList(node.parameters);
+    return visitNode(node);
+  }
+
+  @override
+  bool visitNode(AstNode node) {
+    if (finished) {
+      return true;
+    }
+    return node.parent.accept(this);
+  }
+
+  @override
+  bool visitStringInterpolation(StringInterpolation node) {
+    return visitNode(node);
+  }
+
+  void _visitClassDeclarationMembers(ClassDeclaration node) {
+    node.members.forEach((ClassMember member) {
+      if (member is FieldDeclaration) {
+        member.fields.variables.forEach((VariableDeclaration varDecl) {
+          declaredField(member, varDecl);
+        });
+      } else if (member is MethodDeclaration) {
+        declaredMethod(member);
+      }
+    });
+  }
+
+  void _visitParamList(FormalParameterList paramList) {
+    if (paramList != null) {
+      paramList.parameters.forEach((FormalParameter param) {
+        NormalFormalParameter normalParam;
+        if (param is DefaultFormalParameter) {
+          normalParam = param.parameter;
+        } else if (param is NormalFormalParameter) {
+          normalParam = param;
+        }
+        TypeName type = null;
+        if (normalParam is FieldFormalParameter) {
+          type = normalParam.type;
+        } else if (normalParam is FunctionTypedFormalParameter) {
+          type = normalParam.returnType;
+        } else if (normalParam is SimpleFormalParameter) {
+          type = normalParam.type;
+        }
+        SimpleIdentifier name = param.identifier;
+        declaredParam(name, type);
+      });
+    }
+  }
+}