Syntax for "Function" and "Global" keywords.
BlitzMax Forums/BlitzMax Beginners Area/Syntax for "Function" and "Global" keywords.
| ||
| Hi all. In researching modules and, specifically, the use of the "Extern" keyword, I came across some undocumented syntax. Can someone shed some light? The BlitzMax docs speaks of the following syntax for the "Function" and "Global" keywords, which is fine: Extern Function MyExternFunction(aParam) Function MyExternFunction()="MyExternFunctionAlias" Global MyGlobalVar="HELLO" End Extern But what does these mean? Extern Function MyExternFunction(aParam)=AnotherFunction(AParam) Global MyExternFunction()="StringLiteral" End Extern A function with another function as an alias? Using Global to identify a function? What gives here? Thanks. |
| ||
| The Global one still uses a symbol alias, its still a global just containing a function pointer. The other one, im not too sure. bmx complains about "Unrecognized intermediate expression" no matter what i try :( |
| ||
| Hi grable. Thanks for your reply. About that Global example, I don't think I fully understand. Here is some code: Global b1:Byte = 100 Global b2:Byte = 200 Global b3:Byte = 300 Function MyFunc:Byte Ptr(name$) If (name$ = "Global1") Then Return Varptr b1 If (name$ = "Global2") Then Return Varptr b2 If (name$ = "Global3") Then Return Varptr b3 End Function Global Global1(a$) = MyFunc("Global1") Now, how would I use that Global? |
| ||
| It seems your confusing pointers with function pointers. Im assuming this is the behaviour your after?
Global b1:Byte = 100
Global b2:Byte = 200
Global b3:Byte = 300
Function MyFunc:Byte Ptr( name$)
If (name$ = "Global1") Then Return Varptr b1
If (name$ = "Global2") Then Return Varptr b2
If (name$ = "Global3") Then Return Varptr b3
End Function
Global Global1:Byte Ptr = MyFunc("Global1")
Print "Global1=" + Global1[0]
With parentheses, its a function AND a variable ;) So you could do something like this: Global myprint( s:String) = Print myprint( "hello") But wasnt your original question about Externs?? In which case the same holds true, except the identifiers must be defined elsewhere and imported. |
| ||
| Hi grable. Yes, my original question was about Extern, you are correct. I was only providing an example so I could understand the usage of the resulting Global, which isn't really affected by whether it was defined locally or externally. I understand both of those concepts just fine... but what I want to understand is the concept of a Global having brackets on both sides of the equals sign. As in this code here:
Global alcOpenDevice( devicename$z )=P("alcOpenDevice")
This particular example doesn't have to do with Extern though. (By the way, what are the tags to use to get the code samples appearing in the black+green text on this forum?) Thanks! |
| ||
| {code} {/code} but change the {}'s to []'s or click the forum codes link below |
| ||
| Thanks! I thought I tried that, but I think I used uppercase. Is it case sensitive? |
| ||
| [CODE]Yes[/CODE] |
   |