Entry

BBCBASIC: Windows: How to possibly convert Windows API calls to BBCBASIC Sys calls?

Feb 19th, 2006 13:46
Knud van Eeden,

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--- Knud van Eeden --- 19 February 2021 - 08:25 pm -------------------
BBCBASIC: Windows: How to possibly convert Windows API calls to 
BBCBASIC Sys calls?
---
1. In analyzing the Microsoft Windows API calls, there are 3 modules 
necessary:
 1. a scanner (or lexical analyzer)
 2. a parser (or syntax analyzer)
 3. a semantic analyzer
---
2. You can further analyze a program
   1. top down
   2. bottom up
---
2. From the following given examples of API function calls
 #define IDirect3D_QueryInterface(p,a,b) (p)->lpVtbl->QueryInterface()
 #define IDirect3D_AddRef(p) (p)->lpVtbl->AddRef()
 #define IDirect3D_Release(p) (p)->lpVtbl->Release()
 #define IDirect3D_Initialize(p,a) (p)->lpVtbl->Initialize()
 #define IDirect3D_EnumDevices(p,a,b) (p)->lpVtbl->EnumDevices()
 #define IDirect3D_CreateLight(p,a,b) (p)->lpVtbl->CreateLight()
 #define IDirect3D_CreateMaterial(p,a,b) (p)->lpVtbl->CreateMaterial()
 #define IDirect3D_CreateViewport(p,a,b) (p)->lpVtbl->CreateViewport()
 #define IDirect3D_FindDevice(p,a,b) (p)->lpVtbl->FindDevice()
---
3. You can induce the following general form:
   1. Backus Naur Form for this API functions
--- cut here: begin --------------------------------------------------
 ->-(#)->(define)->-[API function name]->('(')->-+
                                                 |
                                                 |
                                                 |
 +-<---------------------------------------------+
 |
 |   +----<------------+
 |   |                 |
 +->-+->-[parameter]->-+->-(')')->---------------+
     |                 |                         |
     +---->------------+                         |
                                                 |
 +-<---------------------------------------------+
 |
 |
 |
 +->-('(')->-[pointer]->-(')')->-('->')----------+
                                                 |
                                                 |
                                                 |
 +-<---------------------------------------------+
 |
 |
 |
 +->-[left pointer virtual table]->--------------+
                                                 |
                                                 |
                                                 |
 +-<---------------------------------------------+
 |
 |
 |
 +->-('->-')->-[API sub function name]->-('()')->-
--- cut here: end ----------------------------------------------------
3. This Backus Naur Form you could parse, using pseudo code,
   as follows:
   1. Begin at the start
   2. follow the arrows
   3. replace each parallel or serial option by the corresponding fixed
      pseudocode form
   4. until you reach the end
--- cut here: begin --------------------------------------------------
REM --------------------------
REM get '#'
REM --------------------------
if not '#'
 return 'error'
else
 get '#'
endif
REM --------------------------
REM get 'define'
REM --------------------------
s = empty string
if not character in [a-zA-Z_]
 return 'error'
else
 get character
endif
s = character
:
while character in [a-zA-Z_0-9]
 get character
 s = s + character
endwhile
:
if s not equal to 'define'
 return 'error'
endif
REM --------------------------
REM get spaces
REM --------------------------
while ' '
 get ' '
endwhile
REM --------------------------
REM get API function name
REM --------------------------
s = empty string
if not character in [a-zA-Z_]
 return 'error'
else
 get character
endif
s = character
:
while character in [a-zA-Z_0-9]
 get character
 s = s + character
endwhile
REM --------------------------
REM get '(' after API function name
REM --------------------------
if not '('
 return 'error'
else
 get '('
endif
REM --------------------------
REM get parameters
REM --------------------------
s = empty string
repeat
 :
 REM get spaces
 while ' '
  get ' '
 endwhile
 :
 case:
  when character in [a-zA-Z_0-9]
   s = s + character
   get character
   while character in [a-zA-Z_0-9]
    get character
    s = s + character
   endwhile
  when ','
   get ','
 endcase
until current character equals ')'
REM --------------------------
REM get spaces
REM --------------------------
while ' '
 get ' '
endwhile
REM --------------------------
REM get '('
REM --------------------------
if not '('
 return 'error'
else
 get '('
endif
REM --------------------------
REM get spaces
REM --------------------------
while ' '
 get ' '
endwhile
REM --------------------------
REM get 'p'
REM --------------------------
if not 'p'
 return 'error'
else
 get 'p'
endif
REM --------------------------
REM get spaces
REM --------------------------
while ' '
 get ' '
endwhile
REM --------------------------
REM get ')'
REM --------------------------
if not ')'
 return 'error'
else
 get ')'
endif
REM --------------------------
REM get '->'
REM --------------------------
if not '-'
 return 'error'
else
 get '-'
endif
:
if not '>'
 return 'error'
else
 get '>'
endif
REM --------------------------
REM get 'lpVtbl'
REM --------------------------
s = empty string
if not character in [a-zA-Z_]
 return 'error'
else
 get character
endif
s = character
:
while character in [a-zA-Z_0-9]
 get character
 s = s + character
endwhile
:
if s not equal to 'lpVtbl'
 return 'error'
endif
REM --------------------------
REM get '->'
REM --------------------------
if not '-'
 return 'error'
else
 get '-'
endif
:
if not '>'
 return 'error'
else
 get '>'
endif
REM --------------------------
REM get API sub function name
REM --------------------------
s = empty string
if not character in [a-zA-Z_]
 return 'error'
else
 get character
endif
s = character
:
while character in [a-zA-Z_0-9]
 get character
 s = s + character
endwhile
REM --------------------------
REM get '('
REM --------------------------
if not '('
 return 'error'
else
 get '('
endif
REM --------------------------
REM get ')'
REM --------------------------
if not ')'
 return 'error'
else
 get ')'
endif
:
--- cut here: end ----------------------------------------------------
===
Internet: see also:
---
BBCBASIC: Windows: API: BBCBASIC: Operation Convert: Link: Overview: 
Can you give an overview of links?
http://www.faqts.com/knowledge_base/view.phtml/aid/39746/fid/768
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