[Solved] No syntax error?

[BarryG]

Why doesn't this produce a syntax error? I added the "dd" bit on purpose so the IDE would take me back there when I tried to compile after being somewhere else in the source, but no error occurred. The "dd" isn't part of the macro?

Code: Select all

Macro KeyIsDown(key)
  GetAsyncKeyState_(key) & $8000
EndMacro

If KeyIsDown(#VK_SHIFT)dd ; Added "dd" to force a syntax error, but doesn't?
  Debug "down"
EndIf

[infratec]

Add gg and you get an error

You forget what a macro does.
It is a simple text replacement before compilation.

So you get as result :

Code: Select all

If GetAsyncKeyState_(#VK_SHIFT) & $8000dd

And this is valid.

[BarryG]

Ohhhhh, yeah. If I put a space after the closing bracket, then my expected error works

Code: Select all

Macro KeyIsDown(key)
  GetAsyncKeyState_(key) & $8000
EndMacro

If KeyIsDown(#VK_SHIFT) dd ; Added " dd" to force a syntax error, but doesn't?
  Debug "down"
EndIf

[TI-994A]

While PureBasic's Macro() function is quite versatile, and quite different from macros in other languages, it does leave some syntactical rules to be desired.

For example, this simply shouldn't be legal:

Code: Select all

Macro macroHell()
  FindString("Hello", "He
EndMacro

If macroHell()ll") > 0
  Debug "Yes!"
EndIf

[Quin]

While PureBasic's Macro() function is quite versatile, and quite different from macros in other languages, it does leave some syntactical rules to be desired.

For example, this simply shouldn't be legal:

Code: Select all

Macro macroHell()
  FindString("Hello", "He
EndMacro

If macroHell()ll") > 0
  Debug "Yes!"
EndIf

I see no reason to disallow it. The C preprocessor would allow for many, if not all of, the same things. Plus I'm uncertain how this would even be fixed in the compiler, the macros are replaced at compile-time and there would really be no good way of telling the compiler where a macro ends and other tokens start without breaking functionality.

[TI-994A]

The C preprocessor would allow for many, if not all of, the same things.

I'm pretty sure that such expression-concatenation is not possible in C. PureBasic implements its own text-substitution function for its macros.