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petitparser/lib/src/core/actions.dart

-part of petitparser;
-
-/**
- * A parser that performs a transformation with a given function on the
- * successful parse result of the delegate.
- */
-class ActionParser extends DelegateParser {
-  final Function _function;
-
-  ActionParser(parser, this._function) : super(parser);
-
-  @override
-  Result parseOn(Context context) {
-    var result = _delegate.parseOn(context);
-    if (result.isSuccess) {
-      return result.success(_function(result.value));
-    } else {
-      return result;
-    }
-  }
-
-  @override
-  Parser copy() => new ActionParser(_delegate, _function);
-
-  @override
-  bool hasEqualProperties(Parser other) {
-    return other is ActionParser
-        && super.hasEqualProperties(other)
-        && _function == other._function;
-  }
-}
-
-/**
- * A parser that silently consumes input of another parser around
- * its delegate.
- */
-class TrimmingParser extends DelegateParser {
-  Parser _left;
-  Parser _right;
-
-  TrimmingParser(parser, this._left, this._right) : super(parser);
-
-  @override
-  Result parseOn(Context context) {
-    var current = context;
-    do {
-      current = _left.parseOn(current);
-    } while (current.isSuccess);
-    var result = _delegate.parseOn(current);
-    if (result.isFailure) {
-      return result;
-    }
-    current = result;
-    do {
-      current = _right.parseOn(current);
-    } while (current.isSuccess);
-    return current.success(result.value);
-  }
-
-  @override
-  Parser copy() => new TrimmingParser(_delegate, _left, _right);
-
-  @override
-  List<Parser> get children => [_delegate, _left, _right];
-
-  @override
-  void replace(Parser source, Parser target) {
-    super.replace(source, target);
-    if (_left == source) {
-      _left = target;
-    }
-    if (_right == source) {
-      _right = target;
-    }
-  }
-}
-
-/**
- * A parser that answers a substring or sub-list of the range its delegate
- * parses.
- */
-class FlattenParser extends DelegateParser {
-  FlattenParser(parser) : super(parser);
-
-  @override
-  Result parseOn(Context context) {
-    var result = _delegate.parseOn(context);
-    if (result.isSuccess) {
-      var output = context.buffer is String
-          ? context.buffer.substring(context.position, result.position)
-          : context.buffer.sublist(context.position, result.position);
-      return result.success(output);
-    } else {
-      return result;
-    }
-  }
-
-  @override
-  Parser copy() => new FlattenParser(_delegate);
-}
-
-/**
- * A parser that answers a token of the result its delegate parses.
- */
-class TokenParser extends DelegateParser {
-  TokenParser(parser) : super(parser);
-
-  @override
-  Result parseOn(Context context) {
-    var result = _delegate.parseOn(context);
-    if (result.isSuccess) {
-      var token = new Token(
-          result.value, context.buffer, context.position, result.position);
-      return result.success(token);
-    } else {
-      return result;
-    }
-  }
-
-  @override
-  Parser copy() => new TokenParser(_delegate);
-}