langs a-z

Task/Add-a-variable-to-a-class-instance-at-runtime/Objective-C/add-a-variable-to-a-class-instance-at-runtime-1.m

@@ -0,0 +1,21 @@
+#import <Foundation/Foundation.h>
+#import <objc/runtime.h>
+
+char fooKey;
+
+int main (int argc, const char *argv[]) {
+    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
+
+    id e = [[NSObject alloc] init];
+
+    // set
+    objc_setAssociatedObject(e, &fooKey, [NSNumber numberWithInt:1], OBJC_ASSOCIATION_RETAIN);
+
+    // get
+    NSNumber *associatedObject = objc_getAssociatedObject(e, &fooKey);
+    NSLog(@"associatedObject: %@", associatedObject);
+
+    [e release];
+    [pool drain];
+    return 0;
+}

Task/Add-a-variable-to-a-class-instance-at-runtime/Objective-C/add-a-variable-to-a-class-instance-at-runtime-2.m

@@ -0,0 +1,19 @@
+#import <Foundation/Foundation.h>
+#import <objc/runtime.h>
+
+int main (int argc, const char *argv[]) {
+    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
+
+    id e = [[NSObject alloc] init];
+
+    // set
+    objc_setAssociatedObject(e, @selector(foo), [NSNumber numberWithInt:1], OBJC_ASSOCIATION_RETAIN);
+
+    // get
+    NSNumber *associatedObject = objc_getAssociatedObject(e, @selector(foo));
+    NSLog(@"associatedObject: %@", associatedObject);
+
+    [e release];
+    [pool drain];
+    return 0;
+}

Task/Add-a-variable-to-a-class-instance-at-runtime/Octave/add-a-variable-to-a-class-instance-at-runtime.octave

@@ -0,0 +1,3 @@
+% Given struct "test"
+test.b=1;
+test = setfield (test, "c", 3);

Task/Add-a-variable-to-a-class-instance-at-runtime/OxygenBasic/add-a-variable-to-a-class-instance-at-runtime.oxy

@@ -0,0 +1,70 @@
+'=================
+class fleximembers
+'=================
+
+indexbase 0
+bstring buf, *varl
+sys     dp,en
+
+method addVar(string name,dat)
+  sys le=len buf
+  if dp+16>le then
+    buf+=nuls 0x100 : le+=0x100 :
+  end if
+  @varl=?buf
+  varl[en]=name
+  varl[en+1]=dat
+  dp+=2*sizeof sys
+  en+=2 'next slot
+end method
+
+method find(string name) as sys
+  sys i
+  for i=0 to <en step 2
+    if name=varl[i] then return i+1
+  next
+end method
+
+method vars(string name) as string
+  sys f=find(name)
+  if f then return varl[f]
+end method
+
+method VarF(string name) as double
+  return vars(name)
+end method
+
+method VarI(string name) as sys
+  return vars(name)
+end method
+
+method vars(string name,dat)
+  bstring varl at buf
+  sys f=find(name)
+  if f then varl[f]=dat
+end method
+
+method delete()
+  sys i
+  sys v at buf
+  for i=0 to <en
+     freememory v[i]
+  next
+  freememory ?buf
+  ? buf=0 : en=0 : dp=0
+end method
+
+end class
+
+'TEST
+
+fleximembers a
+
+a.addVar "p",5
+a.addVar "q",4.5
+a.addVar "r","123456"
+
+print a.Vars("q")+a.vars("q") 'result 4.54.5
+print a.Varf("q")+a.varf("q") 'result 9
+
+a.delete

Task/Add-a-variable-to-a-class-instance-at-runtime/Oz/add-a-variable-to-a-class-instance-at-runtime.oz

@@ -0,0 +1,29 @@
+declare
+  %% Creates a new class derived from BaseClass
+  %% with an added feature (==public immutable attribute)
+  fun {AddFeature BaseClass FeatureName FeatureValue}
+     class DerivedClass from BaseClass
+        feat
+	   %% "FeatureName" is escaped, otherwise a new variable
+	   %% refering to a private feature would be created
+           !FeatureName:FeatureValue
+     end
+  in
+     DerivedClass
+  end
+
+  class Base
+     feat
+        bar:1
+
+     meth init
+        skip
+     end
+  end
+
+  Derived = {AddFeature Base foo 2}
+
+  Instance = {New Derived init}
+in
+  {Show Instance.bar} %% inherited feature
+  {Show Instance.foo} %% feature of "synthesized" class

Task/Add-a-variable-to-a-class-instance-at-runtime/Perl-6/add-a-variable-to-a-class-instance-at-runtime-1.pl6

@@ -0,0 +1,22 @@
+class Bar { }             # an empty class
+
+my $object = Bar.new;     # new instance
+
+role a_role {             # role to add a variable: foo,
+   has $.foo is rw = 2;   # with an initial value of 2
+}
+
+$object does a_role;      # compose in the role
+
+say $object.foo;          # prints: 2
+$object.foo = 5;          # change the variable
+say $object.foo;          # prints: 5
+
+my $ohno = Bar.new;       # new Bar object
+#say $ohno.foo;           # runtime error, base Bar class doesn't have the variable foo
+
+my $this = $object.new;   # instantiate a new Bar derived from $object
+say $this.foo;            # prints: 2 - original role value
+
+my $that = $object.clone; # instantiate a new Bar derived from $object copying any variables
+say $that.foo;            # 5 - value from the cloned object

Task/Add-a-variable-to-a-class-instance-at-runtime/Perl-6/add-a-variable-to-a-class-instance-at-runtime-2.pl6

@@ -0,0 +1,4 @@
+my $lue = 42 but role { has $.answer = "Life, the Universe, and Everything" }
+
+say $lue;          # 42
+say $lue.answer;   # Life, the Universe, and Everything

Task/Add-a-variable-to-a-class-instance-at-runtime/Perl-6/add-a-variable-to-a-class-instance-at-runtime-3.pl6

@@ -0,0 +1,5 @@
+use MONKEY_TYPING;
+augment class Int {
+    method answer { "Life, the Universe, and Everything" }
+}
+say 42.answer;     # Life, the Universe, and Everything

Task/Add-a-variable-to-a-class-instance-at-runtime/Pike/add-a-variable-to-a-class-instance-at-runtime.pike

@@ -0,0 +1,31 @@
+class CSV
+{
+    mapping variables = ([]);
+
+    mixed `->(string name)
+    {
+        return variables[name];
+    }
+
+    void `->=(string name, mixed value)
+    {
+        variables[name] = value;
+    }
+
+    array _indices()
+    {
+        return indices(variables);
+    }
+}
+
+object csv = CSV();
+csv->greeting = "hello world";
+csv->count = 1;
+csv->lang = "Pike";
+
+indices(csv);
+Result: ({ /* 3 elements */
+              "lang",
+              "count",
+              "greeting"
+         })

Task/Add-a-variable-to-a-class-instance-at-runtime/Pop11/add-a-variable-to-a-class-instance-at-runtime.pop11

@@ -0,0 +1,28 @@
+lib objectclass;
+
+define :class foo;
+enddefine;
+
+define define_named_method(method, class);
+    lvars method_str = method >< '';
+    lvars class_str = class >< '';
+    lvars method_hash_str = 'hash_' >< length(class_str) >< '_'
+                              >< class_str >< '_' >< length(method_str)
+                              >< '_' >< method_str;
+    lvars method_hash = consword(method_hash_str);
+    pop11_compile([
+        lvars ^method_hash = newassoc([]);
+        define :method ^method(self : ^class);
+            ^method_hash(self);
+        enddefine;
+        define :method updaterof ^method(val, self : ^class);
+            val -> ^method_hash(self);
+        enddefine;
+    ]);
+enddefine;
+
+define_named_method("met1", "foo");
+lvars bar = consfoo();
+met1(bar) =>  ;;; default value -- false
+"baz" -> met1(bar);
+met1(bar) =>  ;;; new value

Task/Add-a-variable-to-a-class-instance-at-runtime/PowerShell/add-a-variable-to-a-class-instance-at-runtime.psh

@@ -0,0 +1,5 @@
+$x = 42 `
+     | Add-Member -PassThru `
+        NoteProperty `
+        Title `
+        "The answer to the question about life, the universe and everything"

Task/Add-a-variable-to-a-class-instance-at-runtime/REBOL/add-a-variable-to-a-class-instance-at-runtime.rebol

@@ -0,0 +1,50 @@
+REBOL [
+	Title: "Add Variables to Class at Runtime"
+	Author: oofoe
+	Date: 2009-12-04
+	URL: http://rosettacode.org/wiki/Adding_variables_to_a_class_instance_at_runtime
+]
+
+; As I understand it, a REBOL object can only ever have whatever
+; properties it was born with. However, this is somewhat offset by the
+; fact that every instance can serve as a prototype for a new object
+; that also has the new parameter you want to add.
+
+; Here I create an empty instance of the base object (x), then add the
+; new instance variable while creating a new object prototyped from
+; x. I assign the new object to x, et voila', a dynamically added
+; variable.
+
+x: make object! [] ; Empty object.
+
+x: make x [
+	newvar: "forty-two" ; New property.
+]
+
+print "Empty object modifed with 'newvar' property:"
+probe x
+
+; A slightly more interesting example:
+
+starfighter: make object! [
+	model: "unknown"
+	pilot: none
+]
+x-wing: make starfighter [
+	model: "Incom T-65 X-wing"
+]
+	
+squadron: reduce [
+	make x-wing [pilot: "Luke Skywalker"]
+	make x-wing [pilot: "Wedge Antilles"]
+	make starfighter [
+		model: "Slayn & Korpil B-wing"
+		pilot: "General Salm"
+	]
+]
+
+; Adding new property here.
+squadron/1: make squadron/1 [deathstar-removal-expert: yes]
+
+print [crlf "Fighter squadron:"]
+foreach pilot squadron [probe pilot]

Task/Add-a-variable-to-a-class-instance-at-runtime/Slate/add-a-variable-to-a-class-instance-at-runtime.slate

@@ -0,0 +1,3 @@
+define: #Empty -> Cloneable clone.
+define: #e -> Empty clone.
+e addSlotNamed: #foo valued: 1.