The Ring programming language version 1.5.2 book - Part 32 of 181

The Ring programming language version 1.5.2 book - Part 32 of 181

• 1.
  Ring Documentation, Release1.5.2 Package Package1 Class class1 Func f1 Package Package2 Class class1 Func f1 Package Package3 Class class1 Func f1 Package Package4 Class class1 Func f1 Output: 1 1 0 1 41.11 classes() Function We can get a list of classes names using the classes() function. Syntax: classes() --> a list contains classes names Example: See classes() Class class1 Func f1 Class class2 Func f1 Class class3 Func f1 Output: class1 class2 class3 41.12 isclass() Function We can check if a class is defined or not using the isclass() function. Syntax: 41.11. classes() Function 285
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  Ring Documentation, Release1.5.2 isclass(cClassName) --> returns 1 if the Class is defined returns 0 if the Class is not defined Example: see isclass("class4") + nl + isclass("class3") + nl + isclass("class2") + nl Class class1 func f1 class class2 func f1 class class3 func f1 Output: 0 1 1 41.13 packageclasses() Function We can get a list of classes names inside a package using the packageclasses() function. Syntax: packageclasses(cPackageName) --> a list contains classes names inside the package Example: see "classes in Package1" + nl see packageclasses("Package1") see "classes in Package2" + nl see packageclasses("Package2") Package Package1 Class class1 Func f1 Package Package2 Class class1 Func f1 Class class2 Func f1 Class class3 func f1 Output: classes in Package1 class1 classes in Package2 class1 41.13. packageclasses() Function 286
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  Ring Documentation, Release1.5.2 class2 class3 41.14 ispackageclass() Function We can check if a class is defined inside package or not using the ispackageclass() function. Syntax: ispackageclass(cPackageName,cClassName) --> returns 1 if the Class is defined returns 0 if the Class is not defined Example: see ispackageclass("package1","class1") + nl + ispackageclass("package1","class2") + nl + ispackageclass("package2","class1") + nl + ispackageclass("package2","class2") + nl Package Package1 Class class1 Func f1 Package Package2 Class class1 Func f1 Class class2 Func f1 Class class3 func f1 Output: 1 0 1 1 41.15 classname() Function We can know the class name of an object using the classname() function Syntax: classname(object) --> Returns the object class name Example: o1 = new point o2 = new rect see classname(o1) + nl # print point see classname(o2) + nl # print rect class point class rect 41.14. ispackageclass() Function 287
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  Ring Documentation, Release1.5.2 41.16 objectid() Function We can know the object id using the objectid() function Syntax: objectid(object) --> Returns the object id Example: o1 = new point see objectid(o1) + nl test(o1) func test v see objectid(v) + nl Class point x y z Output: 021B5808 021B5808 41.17 isobject() Function We can check the variable to know if it’s an object or not using the isobject() function Syntax: isobject(variable) --> Returns True if it's an object, False if it's not 41.18 attributes() Function We can get the object attributes using the attributes() function Syntax: attributes(object) --> Returns a list contains the object attributes Example: o1 = new point aList = attributes(o1) # we can use see attributes(o1) for t in aList see t next # print xyz Class Point x y z 41.19 methods() Function We can get the object methods using the methods() function Syntax: 41.16. objectid() Function 288
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  Ring Documentation, Release1.5.2 methods(object) --> Returns a list contains the object methods Example: o1 = new test aList = methods(o1) for x in aList cCode = "o1."+x+"()" eval(cCode) next Class Test func f1 see "hello from f1" + nl func f2 see "hello from f2" + nl func f3 see "hello from f3" + nl func f4 see "hello from f4" + nl Output: hello from f1 hello from f2 hello from f3 hello from f4 41.20 isattribute() Function We can test if the object contains an attribute or not using the isattribute() function Syntax: isattribute(object,cAttributeName) --> Returns True if the object contains the attribute Example: o1 = new point see isattribute(o1,"x") + nl # print 1 see isattribute(o1,"t") + nl # print 0 see isattribute(o1,"y") + nl # print 1 see isattribute(o1,"z") + nl # print 1 class point x y z 41.21 isprivateattribute() Function We can test if the object contains a private attribute or not using the isprivateattribute() function Syntax: 41.20. isattribute() Function 289
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  Ring Documentation, Release1.5.2 isprivateattribute(object,cAttributeName) --> Returns True if the object contains the private attribute Example: o1 = new person see isprivateattribute(o1,"name") + nl + isprivateattribute(o1,"address") + nl + isprivateattribute(o1,"phone") + nl + isprivateattribute(o1,"job") + nl + isprivateattribute(o1,"salary") Class Person name address phone private job salary Output: 0 0 0 1 1 41.22 ismethod() Function We can test if the object class contains a method or not using the ismethod() function Syntax: ismethod(object,cMethodName) --> Returns True if the object class contains the method Example: o1 = new point see ismethod(o1,"print") + nl # print 1 mylist = [] mylist + new point see ismethod(mylist[1],"print") + nl # print 1 class point x y z func print see x + nl + y + nl + z + nl 41.23 isprivatemethod() Function We can test if the object class contains a private method or not using the isprivatemethod() function Syntax: 41.22. ismethod() Function 290
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  Ring Documentation, Release1.5.2 isprivatemethod(object,cMethodName) --> Returns True if the object class contains the private method Example: o1 = new Test see isprivatemethod(o1,"f1") + nl + isprivatemethod(o1,"f2") Class Test func f1 see "message from f1()" + nl private func f2 see "message from f2()" + nl Output: 0 1 41.24 addattribute() Function We can add an attribute (or a group of attributes) to the object state (not the class) using the addattribute() function Syntax: AddAttribute(object,cAttributeName|aAttributesList) Example(1): see new point {x=10 y=20 z=30} Class Point AddAttribute(self,["x","y","z"]) Example(2): o1 = new point addattribute(o1,"x") addattribute(o1,"y") addattribute(o1,"z") see o1 {x=10 y=20 z=30} class point Output: x: 10.000000 y: 20.000000 z: 30.000000 41.25 addmethod() Function We can add a method to the object class using the addmethod() function This method can be used with any object from the same class. 41.24. addattribute() Function 291
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  Ring Documentation, Release1.5.2 Syntax: AddMethod(Object,cNewMethodName,cMethodName|AnonymousFunction) Example: o1 = new point { x=10 y=20 z=30 } addmethod(o1,"print", func { see x + nl + y + nl + z + nl } ) o1.print() Class point x y z Output: 10 20 30 Instead of using anonymous function to add new method to the class, we can use the function name Example: o1 = new point { x=10 y=20 z=30 } myfunc = func { see x + nl + y + nl + z + nl } addmethod(o1,"print", myfunc ) addmethod(o1,"display", myfunc ) addmethod(o1,"show", myfunc ) o1.print() o1.display() o1.show() Class point x y z Output: 10 20 30 10 20 30 10 20 30 Since we add the method to the class, any object from that class can use this method Example: o1 = new point { x=10 y=20 z=30 } o2 = new point { x=100 y=200 z=300 } o3 = new point { x=50 y=150 z=250 } addmethod(o1,"print", func { see x + nl + y + nl + z + nl } ) 41.25. addmethod() Function 292
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  Ring Documentation, Release1.5.2 o1.print() o2.print() o3.print() Class point x y z Output: 10 20 30 100 200 300 50 150 250 41.26 getattribute() function We can get the object attribute value using the getattribute() function Syntax: GetAttribute(oObject,cAttributeName) ---> Attribute Value Example: o1 = new point see getattribute(o1,"name") + nl + getattribute(o1,"x") + nl + getattribute(o1,"y") + nl + getattribute(o1,"z") + nl Class Point x=10 y=20 z=30 name = "3D-Point" Output: 3D-Point 10 20 30 Example: We can Find a Class List Member using GetAttribute() using a function findclass() The Find uses the member name, rather than the column number myList = [new Company {position=3 name="Mahmoud" symbol="MHD"}, new Company {position=2 name="Bert" symbol="BRT"}, new Company {position=1 name="Ring" symbol="RNG"} ] 41.26. getattribute() function 293
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  Ring Documentation, Release1.5.2 see myList see nl +"=====================" + nl + nl for i = 1 to len(myList) see "Pos: "+ i +" | "+ myList[i].position +" | "+ myList[i].name + " | "+ myList[i].symbol +" | "+ nl next See findclass(myList, "MHD", "symbol") +nl ### Specify Member class name ###--------------------------------------- func findclass classList, cValue, classMember See nl + "FindClass: " +" "+ cValue + nl + nl for i = 1 to len(classList) result = getattribute( classList[i], classMember ) See "Result-Attr: " + i +" "+ result +nl if result = cValue j = i ok next return j ###-------------------------------------- class company position name symbol Output: Pos: 1 | 3 | Mahmoud | MHD | Pos: 2 | 2 | Bert | BRT | Pos: 3 | 1 | Ring | RNG | FindClass: MHD Result-Attr: 1 MHD Result-Attr: 2 BRT Result-Attr: 3 RNG 1 41.27 setattribute() function We can set the object attribute value using the setattribute() function Syntax: SetAttribute(oObject,cAttributeName,Value) Example: o1 = new person setattribute(o1,"cName","Mahmoud") 41.27. setattribute() function 294