home | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Lift Framework example source code file (ListHelpersSpec.scala)

This example Lift Framework source code file (ListHelpersSpec.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Lift Framework tags/keywords

empty, empty, full, full, insertafterdelta, int, list, list, listhelpers, listhelpers, lists, nil, removedelta, the

The Lift Framework ListHelpersSpec.scala source code

/*
 * Copyright 2007-2011 WorldWide Conferencing, LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package net.liftweb
package util

import org.specs.Specification

import common._


/**
 * Systems under specification for ListHelpers.
 */
object ListHelpersSpec extends Specification("ListHelpers Specification") with ListHelpers {

  "ListHelpers.delta" should {
    "insert after 2" in {
      val ret = delta(List(1, 2, 4, 5), List(1, 2, 3, 4, 5)) {
        case InsertAfterDelta(3, 2) => "ok"
        case _ => "not ok"
      }
      ret must_== List("ok")
    }

    "prepend and append 2,4, 99" in {
      val ret = delta(List(2, 4, 99), List(1, 2, 3, 4, 5)) {
        case InsertAfterDelta(3, 2) => "ok"
        case AppendDelta(5)         => "ok5"
        case RemoveDelta(99)        => "99"
        case InsertAtStartDelta(1)  => "1"
        case InsertAfterDelta(5, 4) => "ok5"
      }
      ret must_== List("1", "ok", "ok5", "99")
    }

    "prepend and append" in {
      val ret = delta(List(4, 2, 99), List(1, 2, 3, 4, 5)) {
        case InsertAfterDelta(3, 2) => "ok"
        case InsertAfterDelta(4, 3) => "ok3"
        case RemoveDelta(4)         => "r4"
        case AppendDelta(5)         => "ok5"
        case RemoveDelta(99)        => "99"
        case InsertAtStartDelta(1)  => "1"
        case InsertAfterDelta(5, 4) => "ok5"
      }
      ret must_== List("1", "r4", "ok", "ok3", "ok5", "99")
    }
  }

  "The ListHelpers first_? function" should {
    "return an Empty can if the list is empty" in {
      first_?((Nil: List[Int]))((i: Int) => true) must_== Empty
    }
    "return an Empty can if no element in the list satisfies the predicate" in {
      first_?(List(1, 2, 3))((i: Int) => i < 0) must_== Empty
    }
    "return a Full can with the first element in the list satisfying the predicate" in {
      first_?(List(1, 2, 3))((i: Int) => i > 0) must_== Full(1)
    }
  }

  "The ListHelpers first function" should {
    "return an Empty can if the list is empty" in {
      first((Nil: List[Int]))((i: Int) => Full(1)) must_== Empty
    }
    "return an Empty can if no element in the list returns a Full can when applied a function" in {
      first(List(1, 2, 3))((i: Int) => Empty) must_== Empty
    }
    "return the first Full can returned by a function f over the list elements" in {
      val f = (i: Int) => i >= 2 match {case true => Full(3) case false => Empty}
      first(List(1, 2, 3))(f) must_== Full(3)
    }
  }

  "The ciGet function on Lists of pairs of string" should {
    "return Empty if the list is Nil" in {
      (Nil: List[(String, String)]).ciGet("") must_== Empty
    }
    "return Empty if no pair has the key as its first element" in {
      List(("one", "1"), ("two", "2")).ciGet("three") must_== Empty
    }
    "return a Full can with the first second value of a pair matching the key" in {
      List(("one", "1"), ("two", "2")).ciGet("one") must_== Full("1")
    }
    "return a Full can with the first second value of a pair matching the key case-insensitively" in {
      List(("one", "1"), ("two", "2"), ("two", "3")).ciGet("two") must_== Full("2")
    }
  }

  "The ListHelpers enumToList and enumToStringList functions" should {
    "convert a java enumeration to a List" in {
      val v: java.util.Vector[Int] = new java.util.Vector[Int]
      v.add(1);
      v.add(2)
      enumToList(v.elements) must_== List(1, 2)
    }
    "convert a java enumeration containing any kind of object to a List of Strings" in {
      val v: java.util.Vector[Any] = new java.util.Vector[Any]
      v.add(1);
      v.add("hello")
      enumToStringList(v.elements) must_== List("1", "hello")
    }
  }

  "The ListHelpers head function (headOr on a list object)" should {
    "return the first element of a list" in {
      List(1).headOr(2) must_== 1
    }
    "return a default value if the list is empty" in {
      head(Nil, 2) must_== 2
    }
    "not evaluate the default valueif list is not empty" in {
      head(List(1), {error("stop"); 2}) must_== 1
    }
  }

  "The ListHelpers listIf function" should {
    "create a List containing an element if the predicate is true" in {
      listIf(true)(1) must_== List(1)
    }
    "return an empty List if the predicate is false" in {
      listIf(false)(1) must_== Nil
    }
    "not evaluate its argument if the predicate is false" in {
      listIf(false)({error("stop"); 1}) must_== Nil
    }
  }

  "The ListHelpers rotateList function (rotate method on a List object)" should {
    "create a List of all the circular permutations of a given list" in {
      List(1, 2, 3).rotate must_== List(List(1, 2, 3), List(2, 3, 1), List(3, 1, 2))
    }
  }

  "The ListHelpers permuteList function (permute method on a List object)" should {
    "create a List of all the permutations of a given list" in {
      List(1, 2, 3).permute must_==
      List(List(1, 2, 3), List(1, 3, 2), List(2, 3, 1), List(2, 1, 3), List(3, 1, 2), List(3, 2, 1))
    }
  }

  "The ListHelpers permuteWithSublists function (permuteAll method on a List object)" should {
    "create a List of all the permutations of a given list" in {
      List(1, 2, 3).permuteAll must_==
      List(
        List(1, 2, 3), List(1, 3, 2), List(2, 3, 1),
        List(2, 1, 3), List(3, 1, 2), List(3, 2, 1),
        List(2, 3), List(3, 2), List(3, 1),
        List(1, 3), List(1, 2), List(2, 1),
        List(3), List(2), List(1))
    }
  }

  "The ListHelpers" should {
    "provide an or method on Lists returning the list itself if not empty or another list if it is empty" in {
      List(1).or(List(2)) must_== List(1)
      (Nil: List[Int]).or(List(2)) must_== List(2)
    }
    "provide a str method on Lists joining the toString value of all elements" in {
      List("h", "e", "l", "l", "o").str must_== "hello"
    }
    "provide a comma method on Lists being an alias for mkString(\", \")" in {
      List("hello", "world").comma must_== "hello, world"
    }
    "provide a join method on Lists being an alias for mkString" in {
      List("hello", "world").join(", ") must_== "hello, world"
    }
    "provide a ? method return true iff the list is not empty" in {
      List().? must beFalse
      List(1).? must beTrue
    }
    "provide a replace method to replace one element of the list at a given position (0-based index)." +
    " If the position is negative, the first element is replaced" in {
      List(1, 2, 3).replace(1, 4) must_== List(1, 4, 3)
      List(1, 2, 3).replace(4, 4) must_== List(1, 2, 3)
      List(1, 2, 3).replace(-1, 4) must_== List(4, 2, 3)
    }
  }

}

Other Lift Framework examples (source code examples)

Here is a short list of links related to this Lift Framework ListHelpersSpec.scala source code file:



my book on functional programming

 

new blog posts

 

Copyright 1998-2019 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.