[LUA]面向对象扩展类

function clone(object)
    local lookup_table = {}
    local function _copy(object)
        if type(object) ~= "table" then
            return object
        elseif lookup_table[object] then
            return lookup_table[object]
        end
        local new_table = {}
        lookup_table[object] = new_table
        for key, value in pairs(object) do
            new_table[_copy(key)] = _copy(value)
        end
        return setmetatable(new_table, getmetatable(object))
    end
    return _copy(object)
end

function class(classname, super)
    local superType = type(super)
    local cls

    if superType ~= "function" and superType ~= "table" then
        superType = nil
        super = nil
    end

    if superType == "function" or (super and super.__ctype == 1) then
        -- inherited from native C++ Object
        cls = {}
        
        if superType == "table" then
            -- copy fields from super
            for k,v in pairs(super) do cls[k] = v end
            cls.__create = super.__create
            cls.super    = super
        else
            cls.__create = super
            cls.ctor = function() end
        end
    
        cls.__cname = classname
        cls.__ctype = 1

        function cls.new(...)
            local instance = cls.__create(...)
            -- copy fields from class to native object
            for k,v in pairs(cls) do instance[k] = v end
            instance.class = cls
            instance:ctor(...)
            return instance
        end
    else
        -- inherited from Lua Object
        if super then
            cls = {}
            setmetatable(cls, {__index = super})
            cls.super = super
        else
            cls = {ctor = function() end}
        end

        cls.__cname = classname
        cls.__ctype = 2 -- lua
        cls.__index = cls

        function cls.new(...)
            local instance = setmetatable({}, cls)
            instance.class = cls
            instance:ctor(...)
            return instance
        end
    end

    return cls
end

function iskindof(obj, className)
    local t = type(obj)

    if t == "table" then
        local mt = getmetatable(obj)
        while mt and mt.__index do
            if mt.__index.__cname == className then
                return true
            end
            mt = mt.super
        end
        return false

    elseif t == "userdata" then

    else
        return false
    end
end

[Objective-C]分数类

// FILE FractionNumber.h

#import

@interface FractionNumber : NSObject {

int numerator;

int denominator;

}

@property(readwrite) int numerator, denominator;

-(id)initWithIntegers:(int)x numbery:(int)y;

- (NSString *)stringValue;

- (float)floatValue;

- (double)doubleValue;

- (void)add:(FractionNumber *)fn;

- (void)sub:(FractionNumber *)fn;

- (void)div:(FractionNumber *)fn;

- (void)mul:(FractionNumber *)fn;

+(int)gcd:(int)x numbery:(int)y;

+(int)lcm:(int)x numbery:(int)y;

+ (FractionNumber *)parseFractionNumberWithString:(NSString *)stringNumber;

+ (FractionNumber *)parseFractionNumberWithFloat:(double)floatNumber;

+ (FractionNumber *)parseFractionNumberWithInteger:(int)intNumber;

@end

// FILE FractionNumber.m

#import "FractionNumber.h"

@implementation FractionNumber

@synthesize numerator, denominator;

-(id)init

{

[super init];

numerator = 0;

denominator = 1;

return self;

}

-(id)initWithIntegers:(int)x numbery:(int)y

{

[super init];

numerator = x;

denominator = y;

return self;

}

- (NSString *)stringValue

{

return [[NSString alloc] initWithFormat:@"%.11g", [self doubleValue]];

}

- (float)floatValue

{

return (float)numerator/(float)denominator;

}

- (double)doubleValue

{

return (double)numerator/(double)denominator;

}

- (id)copy

{

FractionNumber *fn = [[FractionNumber alloc] initWithIntegers:numerator numbery:denominator];

return fn;

}

- (void)add:(FractionNumber *)fn

{

int x1 = numerator;

int y1 = denominator;

int x2 = [fn numerator];

int y2 = [fn denominator];

int lcmnum = [FractionNumber lcm:y1 numbery:y2];

x1 = lcmnum / y1 * x1;

x2 = lcmnum / y2 * x2;

numerator = x1 + x2;

denominator = lcmnum;

int gcdnum = [FractionNumber gcd:numerator numbery:denominator];

while (gcdnum > 1)

{

numerator /= gcdnum;

denominator /= gcdnum;

gcdnum = [FractionNumber gcd:numerator numbery:denominator];

}

}

- (void)sub:(FractionNumber *)fn

{

int x1 = numerator;

int y1 = denominator;

int x2 = [fn numerator];

int y2 = [fn denominator];

int lcmnum = [FractionNumber lcm:y1 numbery:y2];

x1 = lcmnum / y1 * x1;

x2 = lcmnum / y2 * x2;

numerator = x1 - x2;

denominator = lcmnum;

int gcdnum = [FractionNumber gcd:numerator numbery:denominator];

while (gcdnum > 1)

{

numerator /= gcdnum;

denominator /= gcdnum;

gcdnum = [FractionNumber gcd:numerator numbery:denominator];

}

}

- (void)div:(FractionNumber *)fn

{

FractionNumber *newFn = [[FractionNumber alloc] initWithIntegers:[fn denominator] numbery:[fn numerator]];

[self mul:newFn];

[newFn release];

}

- (void)mul:(FractionNumber *)fn

{

int x1 = numerator;

int y1 = denominator;

int x2 = [fn numerator];

int y2 = [fn denominator];

int gcdnum = [FractionNumber gcd:x1 numbery:y2];

while(gcdnum > 1)

{

x1 /= gcdnum;

y2 /= gcdnum;

gcdnum = [FractionNumber gcd:x1 numbery:y2];

}

gcdnum = [FractionNumber gcd:x2 numbery:y1];

while(gcdnum > 1)

{

x2 /= gcdnum;

y1 /= gcdnum;

gcdnum = [FractionNumber gcd:x2 numbery:y1];

}

numerator = x1 * x2;

denominator = y1 * y2;

}

+(int)gcd:(int)x numbery:(int)y

{

return (!y)?x:[self gcd:y numbery:x%y];

}

+(int)lcm:(int)x numbery:(int)y

{

int y1 = x;

int y2 = y;

int gcdnum = [FractionNumber gcd:y1 numbery:y2];

while(gcdnum > 1)

{

y1 /= gcdnum;

y2 /= gcdnum;

gcdnum = [FractionNumber gcd:y1 numbery:y2];

}

return x * y1;

}

+(FractionNumber *)parseFractionNumberWithString:(NSString *)stringNumber

{

if (!stringNumber || [stringNumber length] == 0)

return NULL;

NSRange range = [stringNumber rangeOfString:@"."];

if (range.location == NSNotFound)

{

int number = [stringNumber intValue];

return [FractionNumber parseFractionNumberWithInteger:number];

}

else

{

@try {

[stringNumber doubleValue];

}

@catch (NSException * e) {

@throw e;

}

int floatNumberLength = [stringNumber length] - range.location - 1;

int ten = pow(10, floatNumberLength);

NSArray *numberparts = [stringNumber componentsSeparatedByString:@"."];

int x = [(NSString *)[numberparts objectAtIndex:1] intValue];

//x = (x * (ten - 1) + x);

//int y = ((ten - 1) * ten);

int y = ten;

int gcdnum = [FractionNumber gcd:x numbery:y];

while (gcdnum > 1)

{

x /= gcdnum;

y /= gcdnum;

gcdnum = [FractionNumber gcd:x numbery:y];

}

int num = [(NSString *)[numberparts objectAtIndex:0] intValue];

x += num * y;

FractionNumber *fn = [[FractionNumber alloc] initWithIntegers:x numbery:y];

return fn;

}

}

+(FractionNumber *)parseFractionNumberWithFloat:(double)floatNumber

{

NSString *numberString = [[NSString alloc] initWithFormat:@"%.11g", floatNumber];

FractionNumber *fn = [FractionNumber parseFractionNumberWithString:numberString];

[numberString release];

return fn;

}

+(FractionNumber *)parseFractionNumberWithInteger:(int)intNumber

{

FractionNumber *fn = [[FractionNumber alloc] initWithIntegers:intNumber numbery:1];

return fn;

}

@end