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Diff for /gforth/doc/gforth.ds between versions 1.72 and 1.73

version 1.72, 2000/08/15 20:25:07 version 1.73, 2000/08/15 20:29:46
Line 11366  So first, let's declare methods: Line 11366  So first, let's declare methods:
   
 @example  @example
 : method ( m v -- m' v ) Create  over , swap cell+ swap  : method ( m v -- m' v ) Create  over , swap cell+ swap
   DOES> ( ... o -- ... ) @ over @ + @ execute ;    DOES> ( ... o -- ... ) @@ over @@ + @@ execute ;
 @end example  @end example
   
 During method declaration, the number of methods and instance  During method declaration, the number of methods and instance
Line 11381  Now, we also have to declare instance va Line 11381  Now, we also have to declare instance va
   
 @example  @example
 : var ( m v size -- m v' ) Create  over , +  : var ( m v size -- m v' ) Create  over , +
   DOES> ( o -- addr ) @ + ;    DOES> ( o -- addr ) @@ + ;
 @end example  @end example
   
 As before, a word is created with the current offset. Instance  As before, a word is created with the current offset. Instance
Line 11395  We need a starting point (the base objec Line 11395  We need a starting point (the base objec
   
 @example  @example
 Create object  1 cells , 2 cells ,  Create object  1 cells , 2 cells ,
 : class ( class -- class methods vars ) dup 2@ ;  : class ( class -- class methods vars ) dup 2@@ ;
 @end example  @end example
   
 For inheritance, the vtable of the parent object has to be  For inheritance, the vtable of the parent object has to be
Line 11405  methods of the parent class, which can b Line 11405  methods of the parent class, which can b
 @example  @example
 : end-class  ( class methods vars -- )  : end-class  ( class methods vars -- )
   Create  here >r , dup , 2 cells ?DO ['] noop , 1 cells +LOOP    Create  here >r , dup , 2 cells ?DO ['] noop , 1 cells +LOOP
   cell+ dup cell+ r> rot @ 2 cells /string move ;    cell+ dup cell+ r> rot @@ 2 cells /string move ;
 @end example  @end example
   
 The first line creates the vtable, initialized with  The first line creates the vtable, initialized with
Line 11415  copies the xts from the parent vtable. Line 11415  copies the xts from the parent vtable.
 We still have no way to define new methods, let's do that now:  We still have no way to define new methods, let's do that now:
   
 @example  @example
 : defines ( xt class -- ) ' >body @ + ! ;  : defines ( xt class -- ) ' >body @@ + ! ;
 @end example  @end example
   
 To allocate a new object, we need a word, too:  To allocate a new object, we need a word, too:
   
 @example  @example
 : new ( class -- o )  here over @ allot swap over ! ;  : new ( class -- o )  here over @@ allot swap over ! ;
 @end example  @end example
   
 Sometimes derived classes want to access the method of the  Sometimes derived classes want to access the method of the
Line 11430  first, you could use named words, and se Line 11430  first, you could use named words, and se
 vtable of the parent object.  vtable of the parent object.
   
 @example  @example
 : :: ( class "name" -- ) ' >body @ + @ compile, ;  : :: ( class "name" -- ) ' >body @@ + @@ compile, ;
 @end example  @end example
   
   
Line 11454  Now, implement the two methods, @code{dr Line 11454  Now, implement the two methods, @code{dr
   
 @example  @example
 :noname ( o -- )  :noname ( o -- )
  >r r@ x @ r@ y @ at-xy  r@ text @ r> len @ type ;   >r r@@ x @@ r@@ y @@ at-xy  r@@ text @@ r> len @@ type ;
  button defines draw   button defines draw
 :noname ( addr u o -- )  :noname ( addr u o -- )
  >r 0 r@ x ! 0 r@ y ! r@ len ! r> text ! ;   >r 0 r@@ x ! 0 r@@ y ! r@@ len ! r> text ! ;
  button defines init   button defines init
 @end example  @end example
   
Removed from v.1.72  
changed lines
  Added in v.1.73

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