macros params: parsing brackets recursively?

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Devel99

Joined: 26 Oct 2015
Posts: 30

Devel99 08 Dec 2015, 23:27

maybe someone has seen that on the web, is it possible?
I can surf expression as top-to-down parser but there's no reliable condition to detect that OP enentually has no brackets and represented by binar math operation

I want MATH recursion to stop when OP reaches binary math operation like "smth +" "smth+smth" "+ smth". Is that possible?

thanks

Code:

macro mk_MATH
{
  macro MATH op
  \{
    mk_MATH

    match (b), op
    \\{
      MATH b
    \\}
    match a(b), op
    \\{
      MATH b
    \\}
    match (b)c, op
    \\{
      MATH b
    \\}
    match a(b)c, op
    \\{
      MATH b
    \\}

    ;  match x * y, op
    ;  \\{
    ;  \\}
    ;
    ;  match x / y, op
    ;  \\{
    ;  \\}
    ;
    ;  match x + y, op
    ;  \\{
    ;  \\}
    ;
    ;  match x - y, op
    ;  \\{
    ;  \\}

    purge MATH
  \}
}
mk_MATH

MATH (1 + ((2 * 5) - 4))

08 Dec 2015, 23:27

l_inc

Joined: 23 Oct 2009
Posts: 881

l_inc 09 Dec 2015, 00:18

Devel99
Do you mean something like an elsematch?

Code:

macro mk_MATH
{
  macro MATH op
  \{
    mk_MATH

    match (b), op
    \\{
      MATH b
      rept 0 \\\{
    \\}
    match, \\{ match a(b), op
    \\\{
      MATH b
      MATH a r
      restore r
      rept 0 \\\\{
    \\\}
    match, \\\{ match (b)c, op
    \\\\{
      MATH b
      MATH r c
      restore r
      rept 0 \\\\\{
    \\\\}
    match, \\\\{ match a(b)c, op
    \\\\\{
      ;MATH b
      ;not sure what this case is about
      match \\\\\\{ PREPROCESSING ERROR \\\\\\}
      rept 0 \\\\\\{
    \\\\\}
    match, \\\\\{
      match x * y, op \\\\\\{ rept 1 t:x*y
      \\\\\\\{
        define r t
        display \\\\\\\`x,'*',\\\\\\\`y,'=',\\\\\\\`t,13,10
      \\\\\\\} \\\\\\}
      match x / y, op \\\\\\{ rept 1 t:x/y
      \\\\\\\{
        define r t
        display \\\\\\\`x,'/',\\\\\\\`y,'=',\\\\\\\`t,13,10
      \\\\\\\} \\\\\\}
      match x + y, op \\\\\\{ rept 1 t:x+y
      \\\\\\\{
        define r t
        display \\\\\\\`x,'+',\\\\\\\`y,'=',\\\\\\\`t,13,10
      \\\\\\\} \\\\\\}
      match x - y, op \\\\\\{ rept 1 t:x-y
      \\\\\\\{
        define r t
        display \\\\\\\`x,'-',\\\\\\\`y,'=',\\\\\\\`t,13,10
      \\\\\\\} \\\\\\}
    \\\\\}\\\\}\\\}\\}

    purge MATH
  \}
}
mk_MATH

MATH (1 + ((2 * 5) - 4))

Pure preprocessor solution might be fun, but for something more practical I'd recommend you to go the way described here (irps + virtual + load).

_________________
Faith is a superposition of knowledge and fallacy

09 Dec 2015, 00:18

Devel99

Joined: 26 Oct 2015
Posts: 30

Devel99 09 Dec 2015, 14:01

l_inc Wise ideas =) thanks much. Bookmarked that. But it turns out that prep fails on the following expression:
MATH ([eax + 6] + [ebx - 8])
Straight matching with PLUS wildcard gives me "[eax" and "6] + [ebx - 8]" and extra workaround required
so I moved back to previously implemented MATH <<[eax + 6], +, [ebx - 8]>, *, [ecx + 7]>
at least that worked and produced something like this

Code:

mcr_LDARG [eax + 6]
mcr_LDARG [ebx - 8]
mcr_ADD
mcr_LDARG [ecx + 7]
mcr_MULL
mcr_STFLD ...

thank you for the cool ideas I need to think of that a bit more Smile

09 Dec 2015, 14:01

l_inc

Joined: 23 Oct 2009
Posts: 881

l_inc 09 Dec 2015, 14:47

Devel99
Square brackets is an operator (of dereference) same as "+","-","*","/", but having the highest precedence among these. So providing support for it is not a workaround. It's a part of the design. You just need to process the operators in form of an "elsematch" (to achieve mutually exclusive processing) starting with match [a], op . And I suppose, you won't need excessive parentheses.

_________________
Faith is a superposition of knowledge and fallacy

09 Dec 2015, 14:47

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