MCCollectionTypes.mc4

/* (c) https://github.com/MontiCore/monticore */
package de.monticore.types;

/* This is a MontiCore stable grammar.
 * Adaptations -- if any -- are conservative. */

import de.monticore.types.*;

/**
 * This grammar defines four generics: List<>, Map<,>, Set<>
 * and Optional<> on top of basic types.
 * 
 * These four generics correspond to a typical predefined set of generic 
 * types for example used in connection with UML class diagrams or the
 * OCL.
 * UML associations typically have those association multiplicities and 
 * therefore these types are of interest.
 * 
 * This eases the reuse of type structures in languages similar to Java,
 * that are somewhat simplified, e.g. without general generics.
 *
 * This grammar is part of a hierarchy of types, namely 
 * * types.MCBasicTypes.mc4       
 *   * types/MCArrayTypes.mc4
 *   * types/MCCollectionTypes.mc4  
 *     * types/MCSimpleGenericTypes.mc4
 *       * types/MCFullGenericTypes.mc4    
 *
*/


component grammar MCCollectionTypes
          extends MCBasicTypes {


  /*=================================================================*/
  
  /**
   * MCGenericType covers the following four forms of generics.
   * E.g. in visitors it can also be used to restrict to these 
   * forms of generics even if further generics would be available.
  */
  interface MCGenericType extends MCObjectType;

  /*=================================================================*/

  /* The following definitions use the next-Command and thus  
   * avoid "List" etc. to become keywords
  */

  MCListType implements MCGenericType <200> =
       key("List") "<" MCTypeArgument ">";

  MCOptionalType implements MCGenericType <200> =
       key("Optional") "<" MCTypeArgument ">";

  MCMapType implements MCGenericType <200> =
       key("Map") "<" key:MCTypeArgument "," value:MCTypeArgument ">";

  MCSetType implements MCGenericType <200> =
       key("Set") "<" MCTypeArgument ">";

  /*=================================================================*/


  /**
   *  ASTMCTypeArgument interface describes arguments of generic types.
   *  Eg. such as qualified or primitive types.
   *
   * This is also an extension point for more general type arguments.
  */
  interface MCTypeArgument;

  MCBasicTypeArgument implements MCTypeArgument <200> =
       MCQualifiedType;

  MCPrimitiveTypeArgument implements MCTypeArgument <190> =
       MCPrimitiveType;

}