pkg/docgen: moved model classes into minilibs

pkg/docgen/lib/src/models/parameter.dart

+library docgen.models.parameter;
+
+import '../exports/mirrors_util.dart' as dart2js_util;
+import '../exports/source_mirrors.dart';
+
+import 'annotation.dart';
+import 'doc_gen_type.dart';
+import 'library.dart';
+import 'mirror_based.dart';
+import 'model_helpers.dart';
+
+/// Docgen wrapper around the dart2js mirror for a Dart
+/// method/function parameter.
+class Parameter extends MirrorBased {
+  final ParameterMirror mirror;
+  final String name;
+  final bool isOptional;
+  final bool isNamed;
+  final bool hasDefaultValue;
+  final DocGenType type;
+  final String defaultValue;
+  /// List of the meta annotations on the parameter.
+  final List<Annotation> annotations;
+
+  Parameter(ParameterMirror mirror, Library owningLibrary)
+      : this.mirror = mirror,
+        name = dart2js_util.nameOf(mirror),
+        isOptional = mirror.isOptional,
+        isNamed = mirror.isNamed,
+        hasDefaultValue = mirror.hasDefaultValue,
+        defaultValue = getDefaultValue(mirror),
+        type = new DocGenType(mirror.type, owningLibrary),
+        annotations = createAnnotations(mirror, owningLibrary);
+
+  /// Generates a map describing the [Parameter] object.
+  Map toMap() => {
+    'name': name,
+    'optional': isOptional,
+    'named': isNamed,
+    'default': hasDefaultValue,
+    'type': new List.filled(1, type.toMap()),
+    'value': defaultValue,
+    'annotations': annotations.map((a) => a.toMap()).toList()
+  };
+}