HOM - Revision history

Newacct at 18:38, 7 June 2010

2010-06-07T18:38:04Z

Cbv: /* HOM related messages */ Sorry... not enough coffee yet

2008-05-07T08:48:32Z

HOM related messages: Sorry... not enough coffee yet

Cbv: /* HOM related messages */

2008-05-07T08:46:34Z

HOM related messages

Cbv: /* HOM related messages */

2008-05-07T08:45:15Z

HOM related messages

Cbv: link to Smalltalk

2006-11-27T10:10:12Z

link to Smalltalk

Cbv at 07:46, 4 August 2006

2006-08-04T07:46:58Z

Cbv: Link to Trampoline, added -ifResponds and some beautifications

2006-06-28T10:49:26Z

Link to Trampoline, added -ifResponds and some beautifications

Cbv: Added a link to POC

2006-06-21T09:54:32Z

Added a link to POC

Cbv: Added to categories Objective-C and Snippets

2006-06-21T09:48:11Z

Added to categories Objective-C and Snippets

Cbv: /* What does HOM look like? */

2005-11-03T08:37:16Z

What does HOM look like?

@@ Line 40: / Line 40: @@
    NSArray *array2 = [[array select] hasPrefix: @"t"];
-   NSLog([array2 description]);
+   NSLog(@"%@", array2);
 This will give us all numbers starting with a ''t''
@@ Line 51: / Line 51: @@
    NSArray *array3 = [[array2 reject] hasSuffix: @"e"];
-   NSLog([array3 description]);
+   NSLog(@"%@", array3);
 will return all numbers in ''array2'' that do '''not''' end with an ''e''
@@ Line 62: / Line 62: @@
    NSArray *array4 = [[array3 collect] stringByAppendingString: @" books"];
-   NSLog([array4 description]);
+   NSLog(@"%@", array4);
 will add ''books'' to all objects in ''array3''
@@ Line 74: / Line 74: @@
    NSArray *array5 = [[array collect] mutableCopy];
    [[array5 do] appendString: @" eggplants"];
-   NSLog([array5 description]);
+   NSLog(@"%@", array5);
 will create a mutable copy of ''array'' and append ''eggplants'' to each object.

← Older revision		Revision as of 08:48, 7 May 2008
Line 55:		Line 55:
	will return all numbers in ''array2'' that do '''not''' end with an ''e''		will return all numbers in ''array2'' that do '''not''' end with an ''e''

−	(two~~, four, six, seven, eight~~, ten)	+	(two, ten)

← Older revision		Revision as of 08:46, 7 May 2008
Line 56:		Line 56:

	(two, four, six, seven, eight, ten)		(two, four, six, seven, eight, ten)
		+

	* ''-collect''		* ''-collect''

@@ Line 55: / Line 55: @@
 will return all numbers in ''array2'' that do '''not''' end with an ''e''
-   (two, ten)
+   (two, four, six, seven, eight, ten)
 * ''-collect''

← Older revision		Revision as of 10:10, 27 November 2006
Line 1:		Line 1:
−	HOM (short for ''High Order Messaging'') is a mechanism for encapsulating control structures and other programming patterns. It is similar to blocks in Smalltalk and higher order functions in functional languages.	+	HOM (short for ''High Order Messaging'') is a mechanism for encapsulating control structures and other programming patterns. It is similar to blocks in [[Smalltalk]] and higher order functions in functional languages.

	[[Objective-C]] does not have blocks. They're not a part of the language, although [http://virtualschool.edu/cox/ Brad Cox]'s [http://virtualschool.edu/cox/pub/TaskMaster/index.html TaskMaster Paper] outlines them nicely (and the [http://users.pandora.be/stes/compiler.html Portable Object Compiler] implements them).		[[Objective-C]] does not have blocks. They're not a part of the language, although [http://virtualschool.edu/cox/ Brad Cox]'s [http://virtualschool.edu/cox/pub/TaskMaster/index.html TaskMaster Paper] outlines them nicely (and the [http://users.pandora.be/stes/compiler.html Portable Object Compiler] implements them).

@@ Line 1: / Line 1: @@
 HOM (short for ''High Order Messaging'') is a mechanism for encapsulating control structures and other programming patterns. It is similar to blocks in Smalltalk and higher order functions in functional languages.
-Objective-C does not have blocks. They're not a part of the language, although [http://virtualschool.edu/cox/ Brad Cox]'s [http://virtualschool.edu/cox/pub/TaskMaster/index.html TaskMaster Paper] outlines them nicely (and the [http://users.pandora.be/stes/compiler.html Portable Object Compiler] implements them).
+[[Objective-C]] does not have blocks. They're not a part of the language, although [http://virtualschool.edu/cox/ Brad Cox]'s [http://virtualschool.edu/cox/pub/TaskMaster/index.html TaskMaster Paper] outlines them nicely (and the [http://users.pandora.be/stes/compiler.html Portable Object Compiler] implements them).
 However, it is possible to implement HOM (using [[trampoline|trampolines]]), but HOM is not a language feature at this point.
@@ Line 9: / Line 9: @@
 == What does HOM look like? ==
-Suppose you have an [[NSArray]] myArray containing objects you want to call a message on. Normally you would have to do something like
+Suppose you have an [[NSArray]] containing objects you want to call a message on. Normally you would have to do something like
-   [myArray makeObjectsPerformSelector: @selector(someOtherMessage)];
+   [anArray makeObjectsPerformSelector: @selector(someOtherMessage)];
 With HOM you simply write
-   [[myArray do] someOtherMessage];
+   [[anArray do] someOtherMessage];
 instead.
-Simply put: the ''-do'' message tells myArray to call ''-someOtherMessage'' on each of its objects.
+Simply put: the ''-do'' message tells the array to call ''-someOtherMessage'' on each of its objects.
@@ Line 29: / Line 29: @@
 We start by assuming there's an array
    NSArray *array;
-   dummy = @"one two three four five six seven eight nine ten";
+   array = [@"one two three four five six seven eight nine ten" componentsSeparatedByString: @" "];
 Now let's see how to use HOM methods on that array and what the results will be:

@@ Line 3: / Line 3: @@
 Objective-C does not have blocks. They're not a part of the language, although [http://virtualschool.edu/cox/ Brad Cox]'s [http://virtualschool.edu/cox/pub/TaskMaster/index.html TaskMaster Paper] outlines them nicely (and the [http://users.pandora.be/stes/compiler.html Portable Object Compiler] implements them).
-However, it is possible to implement HOM (using trampolines), but HOM is not a language feature at this point.
+However, it is possible to implement HOM (using [[trampoline|trampolines]]), but HOM is not a language feature at this point.
@@ Line 20: / Line 20: @@
 Simply put: the ''-do'' message tells myArray to call ''-someOtherMessage'' on each of its objects.
 == HOM related messages ==
@@ Line 36: / Line 38: @@
-* -select
+* ''-select''
 Returns members of the array if they respond YES to the argument message -- which necessarily returns a BOOL.
@@ Line 47: / Line 49: @@
-* -reject
+* ''-reject''
 The inverse of ''-select''; it returns the elements responding NO.
@@ Line 58: / Line 60: @@
-* -collect
+* ''-collect''
 Executes the argument message and returns an array of the responses to the argument message.
-   NSArray *array4 = [[array3 collect] stringByAppendingString: @" book"];
+   NSArray *array4 = [[array3 collect] stringByAppendingString: @" books"];
    NSLog([array4 description]);
-will add ''book'' to all objects in ''array3''
+will add ''books'' to all objects in ''array3''
-   ("two book", "ten book")
+   ("two books", "ten books")
@@ Line 125: / Line 127: @@
    [[someArray ignoreExceptions] messageThatMayRaiseAnException];
 [[Category:Objective-C]]
 [[Category:Snippets]]

← Older revision		Revision as of 09:48, 21 June 2006
Line 125:		Line 125:

	[[someArray ignoreExceptions] messageThatMayRaiseAnException];		[[someArray ignoreExceptions] messageThatMayRaiseAnException];
		+
		+
		+	[[Category:Objective-C]]
		+	[[Category:Snippets]]