Screens.fs requirements documentation

Standard conformant labeling

This is an ANS Forth Program with environmental dependencies,

• Requiring ['] WHILE VARIABLE TYPE THEN SWAP SPACE REPEAT R@ R> OVER MOVE MAX LOOP IF I EXIT ELSE DUP DROP DOES> CREATE CR CONSTANT BEGIN @ >R ; : 2SWAP 2DUP 2DROP 2@ 2! 1+ 0= / ." . - , +! + - ! EVALUATE ABORT" ( from the Core word set.
• Requiring U.R PAD NIP ?DO .R \ from the Core Extensions word set.
• Requiring LOAD EVALUATE from the Block word set.
• Requiring THRU SCR LIST \ from the Block Extensions word set.
• Requiring 2VARIABLE from the Double-Number word set.
• Requiring THROW CATCH from the Exception word set.
• Requiring ABORT" from the Exception Extensions word set.
• Requiring PAGE from the Facility word set.
• Requiring READ-FILE R/O OPEN-FILE FILE-SIZE CLOSE-FILE BIN ( from the File Access word set.
• Requiring FREE ALLOCATE from the Memory-Allocation word set.
• Requiring [THEN] [IF] from the Programming-Tools Extensions word set.
• Requiring COMPARE /STRING from the String word set.

Required program documentation

Environmental dependencies

• This program has no known environmental dependencies.
• Requiring the following non-standard words:
  • [unefined] in order to check if a word is missing. [undefined] can be defined in Forth-94 as

            : undefined ( <name> -- f )  BL WORD FIND SWAP DROP 0= ;

 - `[defined]` in order to check for the existence of a word. `[defined]` can be defined in Forth-94 as

            : defined ( <name> -- f )  [undefined] 0= ;

• Using lower case for standard definition names.

Other program documentation

• After loading this program, a Standard System does not exist any longer as standard words from the Block word set are redefined in a non-standard way.