SortNew (GenericNamedArraylist function): Difference between revisions

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to determine the position of their associated item in the new Arraylist.
to determine the position of their associated item in the new Arraylist.


The system intrinsic classes are discussed in "[[Intrinsic classes]]".
The system intrinsic classes are discussed in [[Intrinsic classes|"Intrinsic classes"]].


SortNew is available in ''Sirius Mods'' version 7.3 and later.
SortNew is available in ''Sirius Mods'' version 7.3 and later.
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<td>One or more SortOrder objects, which consist of an ordering direction for the sort and a key to sort by, specified in the form: <tt>order(key)</tt>. The order is either <tt>Ascending</tt> or <tt>Descending</tt>, and the key is a function that is applied to each item in the Arraylist. For example: <p class="code">%alist = %namray:sortnew(descending(length)) </p>
<td>One or more SortOrder objects, which consist of an ordering direction for the sort and a key to sort by, specified in the form: <tt>order(key)</tt>. The order is either <tt>Ascending</tt> or <tt>Descending</tt>, and the key is a function that is applied to each item in the Arraylist. For example: <p class="code">%alist = %namray:sortnew(descending(length)) </p>


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 ''%namrayl'' declaration and that returns a numeric or string value. This is described further in "[[SortOrder class#Specifying a SortOrder's sort key method|Specifying a SortOrder's sort key method]]".</td></tr>
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 ''%namrayl'' declaration and that returns a numeric or string value. This is described further in [[SortOrder class#Specifying a SortOrder's sort key method|"Specifying a SortOrder's sort key method"]].</td></tr>


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the SortOrder <tt>Ascending(This)</tt>,
the SortOrder <tt>Ascending(This)</tt>,
where <tt>This</tt> is the identity function described further
where <tt>This</tt> is the identity function described further
in "[[Collections#Using the This function as the Maximum parameter|Using the This function as the Maximum parameter]]".
in [[Collections#Using the This function as the Maximum parameter|"Using the This function as the Maximum parameter"]].
Therefore, <tt>%namrayl:sortnew(ascending(this)</tt> can be
Therefore, <code>%namrayl:sortnew(ascending(this)</code> can be
specified simply as <tt>%namrayl:sortnew</tt>.
specified simply as <code>%namrayl:sortnew</code>.
See the [[SortNew (Arraylist function)#Examples|SortNew example]].
See the [[SortNew (Arraylist function)#Examples|SortNew example]].
</ul>
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==Examples==
==Examples==


The following request displays a NamedArraylist in its normal sorted-by-label
The following request displays a <var>NamedArraylist</var> in its normal sorted-by-label
order, then in order of a sort based on a Variable member of the user class.
order, then in order of a sort based on a <var>Variable</var> member of the user class.
For additional sorting examples, see [[Collections#Finding collection maxima and minima, and sorting|Finding collection maxima and minima, and sorting]].
For additional sorting examples, see [[Collections#Finding collection maxima and minima, and sorting|"Finding collection maxima and minima, and sorting"]].
<p class="code">b
<p class="code">b
class python
class python

Revision as of 23:07, 2 March 2011

Sort items to an Arraylist (FloatNamedArraylist, NamedArraylist, and UnicodeNamedArraylist classes)


This function sorts the method object NamedArraylist 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 NamedArraylist 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 NamedArraylist 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

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

Syntax terms

%arlnew An Arraylist object to contain the sorted %namrayl items.
%namrayl The input NamedArraylist 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 = %namray: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 %namrayl 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 NamedArraylist 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 NamedArraylist items have equal values after all sort criteria are applied, SortNew returns them in the same order in which they appear in the input NamedArraylist.
  • 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, %namrayl:sortnew(ascending(this) can be specified simply as %namrayl:sortnew. See the SortNew example.

Examples

The following request displays a NamedArraylist in its normal sorted-by-label order, then in order of a sort based on a Variable member of the user class. For additional sorting examples, see "Finding collection maxima and minima, and sorting".

b class python public variable firstname is string len 16 variable surname is string len 16 variable birthdate is float constructor newpy (%sname is string len 16, - %name is string len 16, %bd is float) function myPrint is longstring end public constructor newpy (%sname is string len 16, - %name is string len 16, %bd is float) %this:firstname = %name %this:surname = %sname %this:birthdate = %bd end constructor function myPrint is longstring return %this:firstname with ' ' with - %this:surname with ' ' with - '(born: ' with %this:birthdate with ')' end function end class %i is float %lp is Arraylist of object python %nlp is namedArraylist of object python %nlp = new %nlp('Gilliam') = newpy('Gilliam', 'Terry', '19401122') %nlp('Cleese') = newpy('Cleese', 'John', '19391027') %nlp('Idle') = newpy('Idle', 'Eric', '19430329') %nlp('Palin') = newpy('Palin', 'Michael', '19430505') %nlp('Chapman') = newpy('Chapman', 'Graham', '19410108') %nlp('Jones') = newpy('Jones', 'Terry', '19420201') for %i from 1 to %nlp:count print %nlp:itembynumber(%i):myprint end for Print '======================================' Print 'After the sort by birthdate:' %lp = %nlp:sortnew(ascending(birthdate)) for %i from 1 to %lp:count print %lp(%i):myprint end for end

The result is:

Graham Chapman (born: 19410108) John Cleese (born: 19391027) Terry Gilliam (born: 19401122) Eric Idle (born: 19430329) Terry Jones (born: 19420201) Michael Palin (born: 19430505) ====================================== After the sort by birthdate: John Cleese (born: 19391027) Terry Gilliam (born: 19401122) Graham Chapman (born: 19410108) Terry Jones (born: 19420201) Eric Idle (born: 19430329) Michael Palin (born: 19430505)

See also