RosettaCodeData/Task/Catamorphism/Forth/catamorphism-5.fth

18 lines
440 B
Forth

: each-char ( c-addr u xt -- )
{: xt :} bounds ?do
i c@ xt execute
loop ;
: type-lowercase ( c-addr u -- )
[: dup lowercase? if emit else drop then ;]
each-char ;
\ producing a new string
: upcase ( 'string' -- 'STRING' )
dup cell+ allocate throw -rot
[: ( new-string-addr c -- new-string-addr )
upcase over c+! ;] each-char $@ ;
: count-lowercase ( c-addr u -- n )
0 -rot [: lowercase? if 1+ then ;] each-char ;