SortNew (Arraylist function): Difference between revisions

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{{Template:Arraylist:SortNew subtitle}}
{{Template:Arraylist:SortNew subtitle}}
[[Category:Arraylist methods|SortNew function]]
[[Category:Arraylist methods|SortNew function]]
<!--DPL?? Category:Arraylist methods|SortNew function: Return new sorted Arraylist-->
<!--DPL?? Category:Arraylist methods|<var>SortNew</var> function: Return new sorted Arraylist-->
<p>
<p>
SortNew is a member of the [[Arraylist class]].
<var>SortNew</var> is a member of the [[Arraylist class]].
</p>
</p>


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The sort key function that gets applied to each Arraylist item, which
The sort key function that gets applied to each Arraylist item, which
you identify in the SortNew parameter, must
you identify in the <var>SortNew</var> parameter, must
operate on the item type and return a User Language intrinsic
operate on the item type and return a User Language intrinsic
datatype (Float, String, Longstring, or Unicode) value.
datatype (Float, String, Longstring, or Unicode) value.
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The system intrinsic classes are discussed in "[[Intrinsic classes]]".
The system intrinsic classes are discussed in "[[Intrinsic classes]]".


SortNew is available in ''Sirius Mods'' version 7.3 and later.
<var>SortNew</var> is available in ''Sirius Mods'' version 7.3 and later.
==Syntax==
==Syntax==
{{Template:Arraylist:SortNew syntax}}
{{Template:Arraylist:SortNew syntax}}
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==Usage notes==
==Usage notes==
<ul>
<ul>
<li>If the function applied by SortNew returns string values, SortNew
<li>If the function applied by <var>SortNew</var> returns string values, <var>SortNew</var>
uses the decimal-equivalent value of the character bytes to determine
uses the decimal-equivalent value of the character bytes to determine
the ascending or descending alphabetic order of the associated arraylist items.
the ascending or descending alphabetic order of the associated arraylist items.
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and all letters rank lower than any number.
and all letters rank lower than any number.
<li>If two or more Arraylist items have equal values after all sort criteria
<li>If two or more Arraylist items have equal values after all sort criteria
are applied, SortNew returns them in the same order in which they appear in the
are applied, <var>SortNew</var> returns them in the same order in which they appear in the
input Arraylist.
input Arraylist.
<li>The function in the parameter for SortNew is a method value, not a User Language expression.
<li>The function in the parameter for <var>SortNew</var> is a method value, not a User Language expression.
That is, you cannot provide a function that itself has an argument
That is, you cannot provide a function that itself has an argument
(say, <tt>Char(13)</tt>) as the SortNew parameter.
(say, <tt>Char(13)</tt>) as the <var>SortNew</var> parameter.
<li>As of ''Sirius Mods'' version 7.6, the default ''sortCriteria'' argument is
<li>As of ''Sirius Mods'' version 7.6, the default ''sortCriteria'' argument is
the SortOrder <tt>Ascending(This)</tt>,
the SortOrder <tt>Ascending(This)</tt>,
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Therefore, <tt>%arrayl:sortnew(ascending(this))</tt> can be
Therefore, <tt>%arrayl:sortnew(ascending(this))</tt> can be
specified simply as <tt>%arrayl:sortnew</tt>, as shown in the [[#Examples|example]] below.
specified simply as <tt>%arrayl:sortnew</tt>, as shown in the [[#Examples|example]] below.
<li>[[Sort (Arraylist subroutine)|Sort]] is a subroutine that works like the SortNew function
<li>[[Sort (Arraylist subroutine)|Sort]] is a subroutine that works like the <var>SortNew</var> function
but applies the sort to the method object instead of returning a new Arraylist.
but applies the sort to the method object instead of returning a new Arraylist.
</ul>
</ul>
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</pre>
</pre>


For more examples of the SortNew method, see [[Collections#Finding collection maxima and minima, and sorting|Finding collection maxima and minima, and sorting]].
For more examples of the <var>SortNew</var> method, see [[Collections#Finding collection maxima and minima, and sorting|Finding collection maxima and minima, and sorting]].

Revision as of 23:58, 19 January 2011

Return new sorted Arraylist (Arraylist class)

SortNew is a member of the Arraylist class.

This function sorts the method object Arraylist and returns the sorted result in a new Arraylist. The sort is based on one or more sort criteria which consist of a sorting direction (ascending or descending) paired with a sort key (a function that gets applied to each Arraylist item). Each sort criterion pair is a SortOrder object, and multiple pairs are a SortOrder collection.

The sort key function that gets applied to each Arraylist item, which you identify in the SortNew parameter, must operate on the item type and return a User Language intrinsic datatype (Float, String, Longstring, or Unicode) value. The values returned by the function are sorted into ascending or descending order to determine the position of their associated item in the new Arraylist.

The system intrinsic classes are discussed in "Intrinsic classes".

SortNew is available in Sirius Mods version 7.3 and later.

Syntax

%newList = al:SortNew[( [sortOrder])]

Syntax terms

%arlnew An Arraylist object to contain the sorted %arrayl items.
%arrayl The input Arraylist object.
sortCriteria One or more SortOrder objects, which consist of an ordering direction for the sort and a key to sort by, specified in the form: order(key). The order is either Ascending or Descending, and the key is a function that is applied to each item in the Arraylist. For example:
     %alist = %arrayl:sortnew(descending(length)) 
The function is a method value (a method or class member name literal, or a method variable) for a method that operates on objects of the type specified on the %arrayl declaration and that returns a numeric or string value. This is described further in "Specifying a SortOrder's sort key method".

Usage notes

  • If the function applied by SortNew returns string values, SortNew uses the decimal-equivalent value of the character bytes to determine the ascending or descending alphabetic order of the associated arraylist items. In ascending order, the highest or last lowercase letter is "z"; the highest or last uppercase letter is "Z"; "z" ranks lower than all the uppercase letters; and all letters rank lower than any number.
  • If two or more Arraylist items have equal values after all sort criteria are applied, SortNew returns them in the same order in which they appear in the input Arraylist.
  • The function in the parameter for SortNew is a method value, not a User Language expression. That is, you cannot provide a function that itself has an argument (say, Char(13)) as the SortNew parameter.
  • As of Sirius Mods version 7.6, the default sortCriteria argument is the SortOrder Ascending(This), where This is the identity function described further in "Using the This function as the Maximum parameter". Therefore, %arrayl:sortnew(ascending(this)) can be specified simply as %arrayl:sortnew, as shown in the example below.
  • Sort is a subroutine that works like the SortNew function but applies the sort to the method object instead of returning a new Arraylist.

Examples

The following simple example shows the default sort of an arraylist of integers. Sortnew is specified with no explicit argument, and ascending(this) is the SortOrder argument that is invoked:

    b
    %al is arraylist of float
    %al2 is arraylist of float
    %i is float

    %al = list(9, 11, 4, -5, 17, 3, 6)
    %al2 = %al:sortnew
    for %i from 1 to %al2:count
      print %al2(%i)
    end for

    end

The result is:

    -5
    3
    4
    6
    9
    11
    17

For more examples of the SortNew method, see Finding collection maxima and minima, and sorting.