However, I am pretty sure that all the C compilers on such systems allow 
specification of ASCII assumptions rather than the stupid EBCDIC (designed by 
committee to be stupid). For instance I know that the zOS compiler allows this. 
EBCDIC is a ridiculous encoding, which I won’t be supporting directly I am 
afraid.

 

So, compile the code with ASCII assumptions and feed the EBCDIC as 8 bit 
Unicode and you will be fine.

 

Jim

 

From: Lego Haryanto [mailto:[email protected]] 
Sent: Thursday, October 15, 2009 8:27 PM
To: Jim Idle
Cc: [email protected]
Subject: Re: [antlr-interest] ANTLR C: Question regarding the portability of 
generated lexer C code

 

Jim, thanks for your response ...

I know that in the EBCDIC system we feed a Unicode stream into the lexer, thus 
I'm pretty sure when the generated lexer code I pasted before is executed, it 
is already operating on the 32-bit unicode stream.

The problem is more about the native C compilation in an EBCDIC system like IBM 
z/OS mainframe.

To see if a character from the Unicode stream is an 'A', we have to compare 
with a value 0x0041 ... If we match it with a native 'A' in the code, this will 
not be a match in an EBCDIC C compilation.

Best,
-Lego

On Fri, Oct 16, 2009 at 3:07 AM, Jim Idle <[email protected]> wrote:

ANTLR works internally with 32 bit Unicode (UTF32), not EBCDIC, even if it is 
in 8 bit mode. So you need to convert the EBCDIC to Unicode 8 bits and use the 
‘ASCII’ input stream. A simple way to do this would be to write your own EBCDIC 
input stream that just converted to Unicode code points (essentially 
EBCDIC->ASCII) on the fly via a lookup table. Trivial and should be pretty 
quick.

 

Jim

 

From: [email protected] 
[mailto:[email protected]] On Behalf Of Lego Haryanto
Sent: Tuesday, October 13, 2009 3:51 AM
To: [email protected]
Subject: [antlr-interest] ANTLR C: Question regarding the portability of 
generated lexer C code

 

I just recently noticed that the generated code from my lexer grammar contains 
something like the following snippet:

            .
            .
            else if ( (((LA17_0 >= 'A') && (LA17_0 <= 'Z'))) ) 
            {
                alt17=2;
            }
            else if ( (((LA17_0 >= 'a') && (LA17_0 <= 'z'))) ) 
            {
                alt17=3;
            }
            else if ( (((LA17_0 >= 0x00A0) && (LA17_0 <= 0xD7FF))) ) 
            {
                alt17=4;
            }
            .
            .

The generated code seems to comfortably use 'A' ... 'Z' literals.  This may not 
be good if let's say I compile the generated code in an IBM z/OS EBCDIC 
environment as ['A' .. 'Z'] range contains more than just the 26 alphabet codes 
and the value of the codes are not the same as the ones in Unicode character 
set.

I'm expecting something like in the third expression where 'A' is written 
explicitly as 0x0041 (Unicode for 'A').

Please confirm.

-Lego




-- 
Fear of the LORD is the beginning of knowledge (Proverbs 1:7)




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