retroforth/bin/listener

#/bin/sh
# RETRO12: Interactive Listener
# ---------------------------------------------------------------------
# This is a bit of trickery using shell scripting and RRE to implement
# an interactive environment for Retro.
# ---------------------------------------------------------------------
# To work as expected, input should process as it's entered and not be
# line buffered. I use `stty` to set this mode.

  stty cbreak

# ---------------------------------------------------------------------
# Next, copy the actual Retro source into a temporary file for RRE to
# process.

  cat >/tmp/_listener.forth << 'EOF'
~~~
{{
  :version (-)    @Version #100 /mod putn $. putc putn ;
  :banner  (-)    'RETRO_12_(rx- puts version $) putc nl
                  EOM putn '_MAX,_TIB_@_1025,_Heap_@_ puts here putn nl ;
  :eol?    (c-f)  [ ASCII:CR eq? ] [ ASCII:LF eq? ] [ ASCII:SPACE eq? ] tri or or ;
  :valid?  (s-sf) dup s:length n:-zero? ;
  :ok      (-)    compiling? [ nl 'Ok_ puts ] -if ;
  :gets    (-s)   [ #1025 buffer:set
                    [ getc dup buffer:add eol? ] until
                    buffer:start s:chop ] buffer:preserve ;
---reveal---
  :listen  (-)    banner ok repeat gets valid? [ interpret ok ] [ drop ] choose again ;
}}

listen
~~~
EOF

# ---------------------------------------------------------------------
# Now use RRE (in the current directory) to run the program.

  ./rre /tmp/_listener.forth

# ---------------------------------------------------------------------
# Finally, clean everything up and use `stty` to restore the normal
# input buffering mode.

  rm -f /tmp/_listener.forth
  stty -cbreak