yaml-ast-parser/src/schema.ts

[](https://travis-ci.org/mulesoft-labs/yaml-ast-parser)

'use strict';

/*eslint-disable max-len*/

import common        = require('./common');
import YAMLException = require('./exception');
import {Type} from './type';


function compileList(schema: Schema, name, result) {
  var exclude = [];

  schema.include.forEach(function (includedSchema) {
    result = compileList(includedSchema, name, result);
  });

  schema[name].forEach(function (currentType) {
    result.forEach(function (previousType, previousIndex) {
      if (previousType.tag === currentType.tag) {
        exclude.push(previousIndex);
      }
    });

    result.push(currentType);
  });

  return result.filter(function (type, index) {
    return -1 === exclude.indexOf(index);
  });
}


function compileMap(/* lists... */) {
  var result = {}, index, length;

  function collectType(type) {
    result[type.tag] = type;
  }

  for (index = 0, length = arguments.length; index < length; index += 1) {
    arguments[index].forEach(collectType);
  }

  return result;
}

export interface SchemaDefinition{
  include?:Schema[]
  implicit?:Type[]
  explicit?:Type[]
}

export class Schema {

  include:Schema[]
  implicit:Type[]
  explicit:Type[]

  compiledImplicit:any[]
  compiledExplicit:any[]
  compiledTypeMap:any[]
  constructor(definition:SchemaDefinition) {
    this.include = definition.include || [];
    this.implicit = definition.implicit || [];
    this.explicit = definition.explicit || [];

    this.implicit.forEach(function (type) {
      if (type.loadKind && 'scalar' !== type.loadKind) {
        throw new YAMLException('There is a non-scalar type in the implicit list of a schema. Implicit resolving of such types is not supported.');
      }
    });

    this.compiledImplicit = compileList(this, 'implicit', []);
    this.compiledExplicit = compileList(this, 'explicit', []);
    this.compiledTypeMap = (<any>compileMap)(this.compiledImplicit, this.compiledExplicit);
  }

  static DEFAULT=null;
  static create=function createSchema() {
      var schemas, types;

      switch (arguments.length) {
        case 1:
          schemas = Schema.DEFAULT;
          types = arguments[0];
          break;

        case 2:
          schemas = arguments[0];
          types = arguments[1];
          break;

        default:
          throw new YAMLException('Wrong number of arguments for Schema.create function');
      }

      schemas = common.toArray(schemas);
      types = common.toArray(types);

      if (!schemas.every(function (schema) { return schema instanceof Schema; })) {
        throw new YAMLException('Specified list of super schemas (or a single Schema object) contains a non-Schema object.');
      }

      if (!types.every(function (type) { return type instanceof Type; })) {
        throw new YAMLException('Specified list of YAML types (or a single Type object) contains a non-Type object.');
      }

      return new Schema({
        include: schemas,
        explicit: types
      });
    }
}