How to Check If Macro's "Non-Value" Parameter Is Set?

[c4s]

One advantage of macros is that they can help at writing actual code. So with "non-value" I mean not a regular string, number, variable or anything like that, but something that's part of e.g. a constant's name.

Being kind of new to the interesting world of PB's macro-magic I came up with this rather strange solution:

Code: Select all

Macro _Quote
	"
EndMacro

Macro Test(param=)
	CompilerIf _Quote param _Quote <> "  "  ; Check if it's set
		Debug "set to " + _Quote param _Quote
	CompilerElse
		Debug "not set"
	CompilerEndIf
EndMacro


Test()  ; Not set
Test(yeah)  ; Set to "yeah"

Now my question is if that can be improved? Preferably without the "_quote" workaround.

Just a suggestion: Maybe even the Defined() functionality could be extended?! I'm thinking of something simple like Defined(param) (for this example)...

[Little John]

Interesting question.

The following seems to work, too.
However, I think your solution is better.

Code: Select all

#MyMacroParamTestConstant = 0

Macro Test (param=)
   CompilerIf Defined(MyMacroParamTestConstant#param, #PB_Constant)
      Debug "not set"
   CompilerElse
      Debug "set"
   CompilerEndIf
EndMacro


Test()
Test(yeah)

[c4s]

Thanks Little John, that's a pretty cool idea. When using a predefined constant it's even more compact. I think I prefer your way:

Code: Select all

Macro Test(param=)
	CompilerIf Defined(True#param, #PB_Constant)
		Debug "not set"
	CompilerElse
		Debug "set"
	CompilerEndIf
EndMacro

[Little John]

Hi, that's a nice improvement.

I didn't like the idea myself very much, because there is a pitfall (it's the same with both my original suggestion and your modified version).
I think you are aware of it, but I want to mention it here for the sake of completeness.
Care has to be taken that something like the following will be avoided:

Code: Select all

#TrueLove = 127

Macro Test(param=)
   CompilerIf Defined(True#param, #PB_Constant)
      Debug "not set"
   CompilerElse
      Debug "set"
   CompilerEndIf
EndMacro


Test()
Test(Love)

[GPI]

The original idea is not from me, i only expand it for quotes:

Code: Select all

Macro MacroColon 
  :
EndMacro
Macro MacroQuote 
  "
EndMacro
Macro MacroSingleQuote
  '
EndMacro
Macro JoinMacroParts (P1, P2=, P3=, P4=, P5=, P6=, P7=, P8=) : P1#P2#P3#P4#P5#P6#P7#P8 : EndMacro
Macro CreateMacro (name,macroBody=)
  JoinMacroParts (Macro name, MacroColon, macroBody, MacroColon, EndMacro) : 
EndMacro
Macro CreateQuote (name)
  JoinMacroParts (MacroQuote,name,MacroQuote)
EndMacro
Macro CreateSingleQuote (name)
  JoinMacroParts (MacroSingleQuote,name,MacroSingleQuote)
EndMacro

Macro test (para=)
  CompilerIf CreateQuote(para)=""
    Debug "not set"
  CompilerElse
    Debug "set"
  CompilerEndIf
EndMacro

You can also Create Macro inside a Macro - but it is a little big buggy. You can only define one Macro inside of a Macro, because the "EndMacro" will stop it.

[c4s]

@Little John
Yes, I'm aware of that, but thanks for pointing it out. To avoid that issue (and I'm sure you know that too ) you could simply use a more abstruse constant like #PB_Billboard_SelfPerpendicular.


@GPI
Thanks for the different approach.

[c4s]

I just realized that I need this to be more flexible (than Little John's version that I initially preferred). My first idea (or GPI's) pretty much does what I need -- except that it doesn't work with literal strings. Here is a quick example:

Code: Select all

Macro _Quote
	"
EndMacro

Macro MacroParam(parameter=)
	Bool(_Quote parameter _Quote <> "  ")
EndMacro


; All tests work fine except the last ones containing any strings
Debug Bool(#False = MacroParam())
Debug Bool(#True = MacroParam(yeah))
Debug Bool(#True = MacroParam(123))
Debug Bool(#True = MacroParam(4e5))
Debug Bool(#True = MacroParam(6.7))
Debug Bool(#True = MacroParam('a'))
Debug Bool(#True = MacroParam(#foo))
Debug Bool(#True = MacroParam(8 / 9))
Debug Bool(#True = MacroParam(#foo + #bar))

;Debug Bool(#True = MacroParam("str"))  ; <- How could this be tested? (using the same MacroParam())
;Debug Bool(#True = MacroParam(#foo + "str"))
;Debug Bool(#True = MacroParam("s1" + "s2"))

Obviously strings are a huge problem for this approach because the quote workaround for comparison doesn't work anymore. So how could this be done? Any ideas on how to detect if a macro parameter is a string?

[GPI]

hmm... maybe:

Code: Select all

CompilerIf ""+param <>""

[c4s]

Good idea, but it doesn't work in the following cases (especially the first one):

Code: Select all

Debug Bool(#False = MacroParam())
Debug Bool(#True = MacroParam(#foo))
Debug Bool(#True = MacroParam(8 / 9))
Debug Bool(#True = MacroParam(#foo + #bar))
Debug Bool(#True = MacroParam(#foo + "str"))