cleanup to tools/testing/dart

tools/testing/dart/status_expression.dart

-// Copyright (c) 2011, 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 status_expression;
-
-/**
- * Parse and evaluate expressions in a .status file for Dart and V8.
- * There are set expressions and Boolean expressions in a .status file.
- * The grammar is:
- *   BooleanExpression := $variableName == value | $variableName != value |
- *                        $variableName | (BooleanExpression) |
- *                        BooleanExpression && BooleanExpression |
- *                        BooleanExpression || BooleanExpression
- *
- *   SetExpression := value | (SetExpression) |
- *                    SetExpression || SetExpression |
- *                    SetExpression if BooleanExpression |
- *                    SetExpression , SetExpression
- *
- *  Productions are listed in order of precedence, and the || and , operators
- *  both evaluate to set union, but with different precedence.
- *
- *  Values and variableNames are non-empty strings of word characters, matching
- *  the RegExp \w+.
- *
- *  Expressions evaluate as expected, with values of variables found in
- *  an environment passed to the evaluator.  The SetExpression "value"
- *  evaluates to a singleton set containing that value. "A if B" evaluates
- *  to A if B is true, and to the empty set if B is false.
- */
-
-class ExprEvaluationException {
-  String error;
-
-  ExprEvaluationException(this.error);
-
-  toString() => error;
-}
-
-class Token {
-  static const String LEFT_PAREN = "(";
-  static const String RIGHT_PAREN = ")";
-  static const String DOLLAR_SYMBOL = r"$";
-  static const String UNION = ",";
-  static const String EQUALS = "==";
-  static const String NOT_EQUALS = "!=";
-  static const String AND = "&&";
-  static const String OR = "||";
-}
-
-
-class Tokenizer {
-  String expression;
-  List<String> tokens;
-
-  Tokenizer(String this.expression)
-    : tokens = new List<String>();
-
-  // Tokens are : "(", ")", "$", ",", "&&", "||", "==", "!=", and (maximal) \w+.
-  static final testRegexp =
-      new RegExp(r"^([()$\w\s,]|(\&\&)|(\|\|)|(\=\=)|(\!\=))+$");
-  static final regexp = new RegExp(r"[()$,]|(\&\&)|(\|\|)|(\=\=)|(\!\=)|\w+");
-
-  List<String> tokenize() {
-    if (!testRegexp.hasMatch(expression)) {
-      throw new FormatException("Syntax error in '$expression'");
-    }
-    for (Match match in regexp.allMatches(expression)) tokens.add(match[0]);
-    return tokens;
-  }
-}
-
-
-abstract class BooleanExpression {
-  bool evaluate(Map<String, String> environment);
-}
-
-
-abstract class SetExpression {
-  Set<String> evaluate(Map<String, String> environment);
-}
-
-
-class Comparison implements BooleanExpression {
-  TermVariable left;
-  TermConstant right;
-  bool negate;
-
-  Comparison(this.left, this.right, this.negate);
-
-  bool evaluate(environment) {
-    return
-        negate != (left.termValue(environment) == right.termValue(environment));
-  }
-
-  String toString() =>
-      "(\$${left.name} ${negate ? '!=' : '=='} ${right.value})";
-}
-
-
-class TermVariable {
-  String name;
-
-  TermVariable(this.name);
-
-  String termValue(environment) {
-    var value = environment[name];
-    if (value == null) {
-      throw new ExprEvaluationException(
-          "Could not find '$name' in environment "
-          "while evaluating status file expression.");
-    }
-    return value.toString();
-  }
-}
-
-
-class TermConstant {
-  String value;
-
-  TermConstant(String this.value);
-
-  String termValue(environment) => value;
-}
-
-
-class BooleanVariable implements BooleanExpression {
-  TermVariable variable;
-
-  BooleanVariable(this.variable);
-
-  bool evaluate(environment) => variable.termValue(environment) == 'true';
-  String toString() => "(bool \$${variable.name})";
-}
-
-
-class BooleanOperation implements BooleanExpression {
-  String op;
-  BooleanExpression left;
-  BooleanExpression right;
-
-  BooleanOperation(this.op, this.left, this.right);
-
-  bool evaluate(environment) => (op == Token.AND) ?
-      left.evaluate(environment) && right.evaluate(environment) :
-      left.evaluate(environment) || right.evaluate(environment);
-  String toString() => "($left $op $right)";
-}
-
-
-class SetUnion implements SetExpression {
-  SetExpression left;
-  SetExpression right;
-
-  SetUnion(this.left, this.right);
-
-  // Overwrites left.evaluate(env).
-  // Set.addAll does not return this.
-  Set<String> evaluate(environment) {
-    Set<String> result = left.evaluate(environment);
-    result.addAll(right.evaluate(environment));
-    return result;
-  }
-
-  String toString() => "($left || $right)";
-}
-
-
-class SetIf implements SetExpression {
-  SetExpression left;
-  BooleanExpression right;
-
-  SetIf(this.left, this.right);
-
-  Set<String> evaluate(environment) => right.evaluate(environment) ?
-    left.evaluate(environment) : new Set<String>();
-  String toString() => "($left if $right)";
-}
-
-
-class SetConstant implements SetExpression {
-  String value;
-
-  SetConstant(String v) : value = v.toLowerCase();
-
-  Set<String> evaluate(environment) => new Set<String>.from([value]);
-  String toString() => value;
-}
-
-
-// An iterator that allows peeking at the current token.
-class Scanner {
-  List<String> tokens;
-  Iterator tokenIterator;
-  String current;
-
-  Scanner(this.tokens) {
-    tokenIterator = tokens.iterator;
-    advance();
-  }
-
-  bool hasMore() => current != null;
-
-  void advance() {
-    current = tokenIterator.moveNext() ? tokenIterator.current : null;
-  }
-}
-
-
-class ExpressionParser {
-  Scanner scanner;
-
-  ExpressionParser(this.scanner);
-
-  SetExpression parseSetExpression() => parseSetUnion();
-
-  SetExpression parseSetUnion() {
-    SetExpression left = parseSetIf();
-    while (scanner.hasMore() && scanner.current == Token.UNION){
-      scanner.advance();
-      SetExpression right = parseSetIf();
-      left = new SetUnion(left, right);
-    }
-    return left;
-  }
-
-  SetExpression parseSetIf() {
-    SetExpression left = parseSetOr();
-    while (scanner.hasMore() && scanner.current == "if") {
-      scanner.advance();
-      BooleanExpression right = parseBooleanExpression();
-      left = new SetIf(left, right);
-    }
-    return left;
-  }
-
-  SetExpression parseSetOr() {
-    SetExpression left = parseSetAtomic();
-    while (scanner.hasMore() && scanner.current == Token.OR){
-      scanner.advance();
-      SetExpression right = parseSetAtomic();
-      left = new SetUnion(left, right);
-    }
-    return left;
-  }
-
-
-  SetExpression parseSetAtomic() {
-    if (scanner.current == Token.LEFT_PAREN) {
-      scanner.advance();
-      SetExpression value = parseSetExpression();
-      if (scanner.current != Token.RIGHT_PAREN) {
-        throw new FormatException("Missing right parenthesis in expression");
-      }
-      scanner.advance();
-      return value;
-    }
-    if (!new RegExp(r"^\w+$").hasMatch(scanner.current)) {
-      throw new FormatException(
-          "Expected identifier in expression, got ${scanner.current}");
-    }
-    SetExpression value = new SetConstant(scanner.current);
-    scanner.advance();
-    return value;
-  }
-
-  BooleanExpression parseBooleanExpression() => parseBooleanOr();
-
-  BooleanExpression parseBooleanOr() {
-    BooleanExpression left = parseBooleanAnd();
-    while (scanner.hasMore() && scanner.current == Token.OR) {
-      scanner.advance();
-      BooleanExpression right = parseBooleanAnd();
-      left = new BooleanOperation(Token.OR, left, right);
-    }
-    return left;
-  }
-
-  BooleanExpression parseBooleanAnd() {
-    BooleanExpression left = parseBooleanAtomic();
-    while (scanner.hasMore() && scanner.current == Token.AND) {
-      scanner.advance();
-      BooleanExpression right = parseBooleanAtomic();
-      left = new BooleanOperation(Token.AND, left, right);
-    }
-    return left;
-  }
-
-  BooleanExpression parseBooleanAtomic() {
-    if (scanner.current == Token.LEFT_PAREN) {
-      scanner.advance();
-      BooleanExpression value = parseBooleanExpression();
-      if (scanner.current != Token.RIGHT_PAREN) {
-        throw new FormatException("Missing right parenthesis in expression");
-      }
-      scanner.advance();
-      return value;
-    }
-
-    // The only atomic booleans are of the form $variable == value or
-    // of the form $variable.
-    if (scanner.current != Token.DOLLAR_SYMBOL) {
-      throw new FormatException(
-          "Expected \$ in expression, got ${scanner.current}");
-    }
-    scanner.advance();
-    if (!new RegExp(r"^\w+$").hasMatch(scanner.current)) {
-      throw new FormatException(
-          "Expected identifier in expression, got ${scanner.current}");
-    }
-    TermVariable left = new TermVariable(scanner.current);
-    scanner.advance();
-    if (scanner.current == Token.EQUALS ||
-        scanner.current == Token.NOT_EQUALS) {
-      bool negate = scanner.current == Token.NOT_EQUALS;
-      scanner.advance();
-      if (!new RegExp(r"^\w+$").hasMatch(scanner.current)) {
-        throw new FormatException(
-            "Expected value in expression, got ${scanner.current}");
-      }
-      TermConstant right = new TermConstant(scanner.current);
-      scanner.advance();
-      return new Comparison(left, right, negate);
-    } else {
-      return new BooleanVariable(left);
-    }
-  }
-}
-