\ Dumb Fibonacci microbenchmark in Forth.  See also dumbfib.py,
\ dumbfib.plx, dumbfib.ml, dumbfib.lua, and dumbfib.S.

\ gforth 0.7.3 runs this in 4.4–4.6 seconds on this Celeron N4120,
\ which is about 6× slower than dumbfib.S.  Using Bigforth from
\ <https://bernd-paysan.de/bigforth_2.4.0_i386.deb> it takes
\ 1.965–1.973 seconds instead, which is only 2.9 times slower than
\ dumbfib.S.

: fib dup 2 <= if drop 1 else 1- dup recurse swap 1- recurse + then ;
: .terse 0 <# #s #> type ;  \ prints a number without a trailing space

\ ANS Forth doesn’t define interpretation semantics for `."`; you’re
\ supposed to use `.(` instead.  Gforth and Bigforth both do the right
\ thing with `."` but emitting the ) with `char` is ANS-compliant and
\ isn’t too terrible.

40 dup .( fib() .terse char ) emit .(  = ) fib .terse cr bye