/Branches/1.2/ScintillaNET/Configuration/Samples/forth

\ Note 1: Text after a backslash is a comment until end-of-line.

 \ Note 2: Text within parentheses like "( n -- )" is also a comment.

 \ Note 3: To be strictly ANSI compliant, the code below is in UPPERCASE.

 \	 Most PC Forth implementations are (optionally) case insensitive.



 : STAR	 ( -- ) \ Print a single star

   42 EMIT ;	  \ 42 is the ASCII code for *



 : STARS	( n -- ) \ Print n stars

   0 DO STAR LOOP ;	\ Loop n times (0 up to n-1) and execute STAR



 : SQUARE	( n -- ) \ Print an n-line square of stars

   DUP 0 DO		\ Loop n times, keeping (DUP-licating) n on the stack

   DUP STARS CR	\ Each time, print n stars then print CR

   LOOP DROP ;	\ After loop is done, drop the n from the stack



 : TRIANGLE	( n -- ) \ Print an n-line triangle

   1 + 1 DO		\ Loop n times from 1 to n (instead of 0 to n-1)

   I STARS CR	\ This time use the inner loop index I

   LOOP ;



 : TOWER	( n -- ) \ Print a "tower" with an base of size n

   DUP		\ DUP-licate n (since it is used twice below)

   1 - TRIANGLE	\ Print a triangle 1 size smaller than n

   SQUARE ;		\ Print a square base of size n