Difference between revisions of "Talk:Writing Modules In C"

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(Why do you need to declare a Link* named ink when using FOR_EACH_PLAYER macro?)
 
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quote from article:
 
quote from article:
 
"''There is an ASSS macro, FOR_EACH_PLAYER, that will help us loop through every player. To use this macro we need: a Player* '''and a Link* named link.'''''"
 
"''There is an ASSS macro, FOR_EACH_PLAYER, that will help us loop through every player. To use this macro we need: a Player* '''and a Link* named link.'''''"
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[[User:Mine GO BOOM|Mine GO BOOM]] 15:56, Oct 3, 2006 (PDT): In player.h, the macro FOR_EACH_PLAYER is defined as the following. The for line assumes a '''Link*''' variable named '''link''' for it to work correctly. Under C++, you could initalize the '''link''' variable in the '''for''' loop but you cannot in C. A slightly better method would have the '''Link*''' variable name be include in the macro's definition instead of assuming a variable named '''link'''.
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<pre>#define FOR_EACH_PLAYER(p) \
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        for ( \
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                        link = LLGetHead(&pd->playerlist); \
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                        link && ((p = link->data, link = link->next) || 1); )</pre>

Revision as of 17:56, 3 October 2006

The example given for how to use the FOR_EACH_PLAYER macro doesn't show why you need a Link pointer named link!

The example just declares the variable, without initializing it to any value, and doesn't do anything with the Link pointer after that.

quote from article: "There is an ASSS macro, FOR_EACH_PLAYER, that will help us loop through every player. To use this macro we need: a Player* and a Link* named link."

Mine GO BOOM 15:56, Oct 3, 2006 (PDT): In player.h, the macro FOR_EACH_PLAYER is defined as the following. The for line assumes a Link* variable named link for it to work correctly. Under C++, you could initalize the link variable in the for loop but you cannot in C. A slightly better method would have the Link* variable name be include in the macro's definition instead of assuming a variable named link.

#define FOR_EACH_PLAYER(p) \
        for ( \
                        link = LLGetHead(&pd->playerlist); \
                        link && ((p = link->data, link = link->next) || 1); )