Usually the name of a definition is not visible in the definition; but earlier definitions are usually visible:
1 0 / . \ "Floating-point unidentified fault" in Gforth on some platforms
: / ( n1 n2 -- n )
dup 0= if
-10 throw \ report division by zero
endif
/ \ old version
;
1 0 /
For recursive definitions you can use recursive (non-standard) or
recurse:
: fac1 ( n -- n! ) recursive dup 0> if dup 1- fac1 * else drop 1 endif ; 7 fac1 . : fac2 ( n -- n! ) dup 0> if dup 1- recurse * else drop 1 endif ; 8 fac2 .
Assignment: Write a recursive definition for computing the nth Fibonacci number.
Reference (including indirect recursion): See Calls and returns.