how do infix expression parsing in match?

flat assembler
Message board for the users of flat assembler.

Index > Macroinstructions > how do infix expression parsing in match?

Author

Thread

Roman

Joined: 21 Apr 2012
Posts: 2026

Roman 05 Nov 2025, 11:47

I want do this.

Code:

macro Calc expr { match v,expr \{
\}
}

;in code
a dd  4.0
b dd  3.0
c dd -2.0
e dd  5.0

Calc e + a * b +c  ;could be many values

;get
mov eax,1.0
movd xmm7,eax
mulss xmm7,[a]
mulss xmm7,[b]
addss xmm7,[c]
addss xmm7,[e]

my problem how did sort * or / in macro in match ?

how say match ignoring symbols + * / ?
something like this match ~+,reg

using irps I out:
r equ c
r equ +
r equ b
r equ *
r equ a

match must do e,r \{ r2 equ e\} ;if symbols not + or * than r2 equ e

out
r2 equ c
r2 equ b
r2 equ a

Last edited by Roman on 05 Nov 2025, 13:58; edited 1 time in total

05 Nov 2025, 11:47

revolution
When all else fails, read the source

Joined: 24 Aug 2004
Posts: 20765
Location: In your JS exploiting you and your system

revolution 05 Nov 2025, 13:54

The shunting yard algorithm might be a good place to look for a way to do that.

05 Nov 2025, 13:54

Roman

Joined: 21 Apr 2012
Posts: 2026

Roman 08 Nov 2025, 05:47

I do this

Code:

macro mcalc0 expr {
irps reg, expr \{ common reverse @reqq2 equ reg \} }
mcalc0 2+3*4/2-5 

irpv ttt,@reqq2 {  ;if `ttt <> in <`-, `/,`+,`*> ;fasm error
;if `ttt <> "-" && `ttt <> "/" ;fasm error why ?
                           if `ttt <> "-" ;this ok
                           mov eax,ttt ;fasm error mov eax,/
                           display 't;'
                           end if  }

08 Nov 2025, 05:47

Roman

Joined: 21 Apr 2012
Posts: 2026

Roman 08 Nov 2025, 06:38

o. I do this

Code:

irpv ttt,@reqq2 {  ;if `ttt <> in <`-, `/>
                           if `ttt = "-" | `ttt = "/" | `ttt = "*" | `ttt = "+"
                           mov ebx,`ttt
                           display 't;'
                           else
                           mov eax,ttt
                           end if

        }

08 Nov 2025, 06:38

revolution
When all else fails, read the source

Joined: 24 Aug 2004
Posts: 20765
Location: In your JS exploiting you and your system

revolution 08 Nov 2025, 06:43

It would be easier to express all computations in RPN form. Those are much easier to parse.

08 Nov 2025, 06:43

< Last Thread | Next Thread >

Forum Rules:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum