Is it possible to get ' ' character in match directive? Like so:

works OK, but if you write

works also, and I don't want it.. I want it to work ONLY when you put a space character, not any symbol. It seems the only way to do it is to check all the other symbols, and if it's false, then try with ' ' symbol.. It's quite a big overhead. Just wanted to know if it's possible.



Now, if you define expr 2+2 it will not work anymore, which is good.. sure, I also have to check separately for = and , symbols (since they must be preceeded by =), but I think you get the point.

Is it possible to do it in match directly? Thanks

For preprocessor the blanks are already non-existing (like the comments), the "2 2" is for preprocessor the sequence of two symbols just like "2+2" is the sequence of three (undistinguishable from "2 + 2").
If you want just two symbols, use "irps" and limit it to two first ones.

How can you limit it to first 2 symbols? does % work here (I think it works only for assembler).


maybe I'll need this: how to tell where a space ' ' has occured? Like

alpha beta
alpha+ss beta

and match to make it work, variable 1 contains alpha+ss and variable 2 beta? still, not even my previously posted macro will work

If I do this:

match var1 var2

it will put alpha in var1 and ss in var2, which of course, it's not what I intended.

just wanted to know if it's possible to do it in some 'trick' or maybe something else. thx again

EDIT: oops, sorry.. I wrote the first code wrong.. It should've been match , false, not match +, false.. sorry

Well, actually I perhaps misguided you a bit. To get the two symbols it's better to use just a few matches. Like:



And note once more: for preprocessor there are no spaces, "alpha+ss beta" is the sequence of "alpha", "+", "ss" and "beta" symbols, it doesn't matter whether there were some additional spaces between them or not.

Now it works.. why define a car? seems it not used.

thanks for the tip. I understand it better

Well, you did "match a b" initially, so I defined the "a" and "b" symbols in this example.

Ok, got it. Thanks

Tomasz: Wouldn't it be better to make preprocessor work for symbols only separated with space? Coder can always write match '2 + 2' instead of '2+2'. It would be much easier and IMHO more intuitive. You would always know that '2+2' is one symbol and we would need no such (IMO) messy solutions to distinguish symbols.

Better or not, it would require completely different preprocessor philosophy, thus writing something completely different than flat assembler is now.

Also note that for assembler "2+not 2" is also a single token (single numerical expression). And for preprocessor it's just four tokens.