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September 2017 Update

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Ingy döt Net 2017-09-23 10:01:46 +02:00
parent bba7bfd280
commit ba8067c3b7
14570 changed files with 153136 additions and 63871 deletions
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119
Task/Function-composition/Objective-C/function-composition-1.m
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@ -1,119 +0,0 @@
#include <Foundation/Foundation.h>
// the protocol of objects that can behave "like function"
@protocol FunctionCapsule <NSObject>
-(id)computeWith: (id)x;
@end
// a commodity for "encapsulating" double f(double)
typedef double (*func_t)(double);
@interface FunctionCaps : NSObject <FunctionCapsule>
{
func_t function;
}
+(id)capsuleFor: (func_t)f;
-(id)initWithFunc: (func_t)f;
@end
@implementation FunctionCaps
-(id)initWithFunc: (func_t)f
{
if ((self = [self init])) {
function = f;
}
return self;
}
+(id)capsuleFor: (func_t)f
{
return [[[self alloc] initWithFunc: f] autorelease];
}
-(id)computeWith: (id)x
{
return [NSNumber numberWithDouble: function([x doubleValue])];
}
@end
// the "functions" composer
@interface FunctionComposer : NSObject <FunctionCapsule>
{
id<FunctionCapsule> funcA;
id<FunctionCapsule> funcB;
}
+(id) createCompositeFunctionWith: (id<FunctionCapsule>)A and: (id<FunctionCapsule>)B;
-(id) initComposing: (id<FunctionCapsule>)A with: (id<FunctionCapsule>)B;
@end
@implementation FunctionComposer
+(id) createCompositeFunctionWith: (id<FunctionCapsule>)A and: (id<FunctionCapsule>)B
{
return [[[self alloc] initComposing: A with: B] autorelease];
}
-(id) init
{
[self release];
@throw [NSException exceptionWithName:NSInternalInconsistencyException
reason:@"FunctionComposer: init with initComposing!"
userInfo:nil];
return nil;
}
-(id) initComposing: (id<FunctionCapsule>)A with: (id<FunctionCapsule>)B
{
if ((self = [super init])) {
if ( [A respondsToSelector: @selector(computeWith:)] &&
[B respondsToSelector: @selector(computeWith:)] ) {
funcA = [A retain]; funcB = [B retain];
return self;
}
NSLog(@"FunctionComposer: cannot compose functions not responding to protocol FunctionCapsule!");
[self release];
}
return nil;
}
-(id)computeWith: (id)x
{
return [funcA computeWith: [funcB computeWith: x]];
}
-(void) dealloc
{
[funcA release];
[funcB release];
[super dealloc];
}
@end
// functions outside...
double my_f(double x)
{
return x+1.0;
}
double my_g(double x)
{
return x*x;
}
int main()
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
id<FunctionCapsule> funcf = [FunctionCaps capsuleFor: my_f];
id<FunctionCapsule> funcg = [FunctionCaps capsuleFor: my_g];
id<FunctionCapsule> composed = [FunctionComposer
createCompositeFunctionWith: funcf and: funcg];
printf("g(2.0) = %lf\n", [[funcg computeWith: [NSNumber numberWithDouble: 2.0]] doubleValue]);
printf("f(2.0) = %lf\n", [[funcf computeWith: [NSNumber numberWithDouble: 2.0]] doubleValue]);
printf("f(g(2.0)) = %lf\n", [[composed computeWith: [NSNumber numberWithDouble: 2.0]] doubleValue]);
[pool release];
return 0;
}

42
Task/Function-composition/Objective-C/function-composition-2.m
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@ -1,42 +0,0 @@
#include <Foundation/Foundation.h>
typedef id (^Function)(id);
// a commodity for "encapsulating" double f(double)
typedef double (*func_t)(double);
Function encapsulate(func_t f) {
return [[^(id x) { return [NSNumber numberWithDouble: f([x doubleValue])]; } copy] autorelease];
}
Function compose(Function a, Function b) {
return [[^(id x) { return a(b(x)); } copy] autorelease];
}
// functions outside...
double my_f(double x)
{
return x+1.0;
}
double my_g(double x)
{
return x*x;
}
int main()
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
Function f = encapsulate(my_f);
Function g = encapsulate(my_g);
Function composed = compose(f, g);
printf("g(2.0) = %lf\n", [g([NSNumber numberWithDouble: 2.0]) doubleValue]);
printf("f(2.0) = %lf\n", [f([NSNumber numberWithDouble: 2.0]) doubleValue]);
printf("f(g(2.0)) = %lf\n", [composed([NSNumber numberWithDouble: 2.0]) doubleValue]);
[pool release];
return 0;
}