undef

Undefines defined NCL symbols (functions, procedures, variables).

Prototype

	procedure undef (
		names  : string   
	)

Arguments

String names of any dimensionality of symbols to be undefined.

Description

This procedure should be used primarily to undefine functions and procedures, although it does work for variables. undef will remove from the symbol table any references matching the input.

Warning: once a function, procedure, or variable is undefined, there is no way to get it back.

Examples

Example 1

The example below shows how to redefine the built-in function stringtocharacter to return a character array of a single string without the end-of-string character. We are being sneaky here, because we are using the identical function stringtochar to first return the character array. Note: it is not recommended that you do this, but there it is:

undef("stringtocharacter")
function stringtocharacter(str[1]:string)
local cstr, new_cstr
begin
  cstr     = stringtochar(str)
  new_cstr = cstr(0:dimsizes(cstr)-2)
  return(new_cstr)
end

begin
   str = "Ixnay on the ottenray."
   print(stringtocharacter(str))
end