Call a function: Difference between revisions
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The shell does not support the use of named parameters. There is no lookahead in the shell, so functions cannot be called until their definition has been run.
=={{header|zkl}}==
The syntax and semantics of function calls is the always the same: name/object(parameters). All calls are varargs, it is up to the callee to do default/optional parameter handling (but that is hidden from the programmer). No named parameters. Pass by reference or value, depending.
Using f has a function, method or object:
<lang zkl>f(); f(1,2,3,4);
fcn f(a=1){}() // define and call f, which gets a set to 1
fcn{vm.arglist}(1,2,3,4) // arglist is L(1,2,3,4)
fcn{a1:=vm.nthArg(1)}(1,2,3) // a1 == 2
(f() == True); (f() and 1 or 2)
if (f()) println()
f(f) // pass f to itself
s:=f()
fcn{}.isType(self.fcn) //True
fcn{}.len.isType(self.fcn) //False, len is a Method</lang>
Partial application is done with the .fp* methods or the 'wrap keyword
<lang zkl>
fcn(a,b,c).fp(1)() // call function with a always set to 1
fcn(a,b,c).fp1(2,3)() // call function with b & c always set to 2 & 3
fcn(a,b,c,d).fpN(3,5)() // call function with d always set to 5
fcn{vm.arglist}.fpN(3,66)(1,2,3,4,5) //-->L(1,2,3,66,4,5)
fcn{}.fpM("01-",5) // use a mask to select parameters
// 1 is supplied, 0 is get upon call, - is chop arglist
fcn{vm.arglist}.fpM("01-",66)(1,2,3,4) //-->L(1,66)
a:=5; f('wrap(b){a+b}) // 'wrap is syntactic sugar for .fpN
// to create a lexical closure --> f(fcn(b,a){a+b}.fpN(1,a))</lang>
=={{header|ZX Spectrum Basic}}==
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