#157 call_func() macro

[Bert Wesarg]

unlike most other interpreted language, the nedit macro language suffer from a function, that calls a named function with some arguments. so here is a rough copy'n'paste patch:

syntax:
ret = call_func(name[, arguments for named function...])

[Bert Wesarg]

[Bert Wesarg]

a multiplexer for the file_open_hook()

[Bert Wesarg]

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a natural use of the call_func() macro. only usable with the Patch Collection patch from Thorsten Haude (see: http://sourceforge.net/tracker/index.php?func=detail&aid=1058246&group_id=11005&atid=311005\)

File Added: hook.nm

[Bert Wesarg]

a generic hook multiplexer

[Bert Wesarg]

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a more generic hook multiplexer, needs the define_func() patch (see: http://sourceforge.net/tracker/index.php?func=detail&aid=1640333&group_id=11005&atid=311005\):

defines two functions

callback_register(string hook, string function)
callback_deregister(string hook, string function)

if it's the first function for an hook, a new multiplexer function is generated with the define_func() routine

there is only one problem: hooks that gets a parameter, this case isn't handled at all
File Added: hook.nm

[Bert Wesarg]

a generic hook multiplexer, gen2

[Bert Wesarg]

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fixing the generic multiplexer
File Added: hook.nm

[Bert Wesarg]

gen2

[Bert Wesarg]

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this new version adds a second function named "call_func_with_args". this function takes a array as second parameter, and calls the named function with the arguments from this array. this array is of the same form like the $args array.

syntax:
[ret = ]call_func_with_args(string name, array args)

is equivalent to:
[ret = ]name(args[1], args[2], ...)

File Added: call_func.patch

[Bert Wesarg]

a generic hook multiplexer, gen3

[Bert Wesarg]

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update the generic hook multiplexer to use the new call_func_with_args() macro. now the case where hooks get arguments are handled

File Added: hook.nm

[Tony Balinski]

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This would be more useful if it could replace itself with the called function in the original macro context. That way limitations concerning pre-emption could be avoided where possible. It's not that difficult to do: break callSubroutine() in interpret.c into callSubroutineFromSymbol(sym,nArgs) and a wrapper called callSubroutine() which finds the values to pass to ...FromSymbol(), then calls it. Then create a macro built-in "call(name,...)" (callMS()) which does a symbol lookup to find the function for name, then calls a new function in interpret.c which adjusts the arguments in the stack (to remove the symbol name argument) then calls callSubroutineFromSymbol(). (I called this last function OverlayRoutineFromStack(sym,nArgs,nRemoveArgs).) I haven't tried an equivalent call_func_with_args() yet, but it shouldn't take much...

[Bert Wesarg]

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I have no deeply knowledge of the nedit interpreter and i can't follow
your reason with the pre-emption, if you think it should be implemented
your way, than feel free to do so. I just naivly copy'n'paste code from
interpret.c into a new macro subroutine and figured out that it Just
Worked. But that reminds me of the following feature, you have bring to
disussion, and i do it here again:

a = "length"
len = a("string")

how about this (this doesn't adress the call_func_with_args() macro):
diff --quilt old/source/interpret.c new/source/interpret.c
--- old/source/interpret.c
+++ new/source/interpret.c
@@ -2038,10 +2038,22 @@ static int callSubroutine(void)

DISASM_RT(PC-3, 3);
STACKDUMP(nArgs, 3);

/*
+ ** If the symbol is a string, try to resolve the string to a symbol
+ */
+ if (sym->type == GLOBAL_SYM) {
+ if (sym->value.tag == STRING_TAG) {
+ Symbol *newsym = LookupSymbol(sym->value.val.str.rep);
+ if (newsym) {
+ sym = newsym;
+ }
+ }
+ }
+
+ /*
** If the subroutine is built-in, call the built-in routine
*/
if (sym->type == C_FUNCTION_SYM) {
DataValue result;

[Tony Balinski]

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Yes, I think that's almost exactly what I did, except that I didn't force the symbol to be global. I must say that, though it works well, I don't much like it. (It makes me uneasy, it's so flexible!) The more explicit macro function call(name,...) provides the same functionality more explicitly.