isCallable

isCallable( 
s_function 
) 
=> t / nil

Checks if a function is defined or is autoloadable from a context.

s_function

Name of a function.

`t`	The specified function is defined or is autoloadable.
`nil`	The specified function is not defined or is not autoloadable.

isCallable( 'car) 
=> t

procedure( myFunction( x ) x+1)
isCallable('myFunction) 
=> t