Parsing Code Words

These words are used to parse code words in Janus when compiling the target code. The process is the same as when processing regular words, with the difference being that any numbers in the input stream are compiled into the target word. Only half-words are suppored.

First, the inner loop which parses the input stream and adds numbers to the target word:

: parse-code    begin  bl word  dup c@ while
                  find ?dup if
                    1+ if execute else , then
                  else
                    ?number if
                      h,
                    else count type [char] ? emit cr then
                  then
                repeat drop ;

Immediate words are executed, non-numbers will cause a warning and will be ignored.

The outer loop runs until the state is switched back to interpretation mode:

: read-code     ] begin
                  parse-code
                  state @ 0= if exit then
                  refill
                0= until ;

The code definition word creates a target dictionary entry and proceeds to parse the subsequent numer stream.

: code <builds  read-code ; immediate

Finalize a code word by turning off the compiler.

: end-code      [ ; immediate