retroforth/takawiri.retro

#!/usr/bin/env retro

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  _        _                  _      _
 | |_ __ _| | ____ ___      _(_)_ __(_)  crc's new listener for
 | __/ _` | |/ / _` \ \ /\ / / | '__| |  RetroForth
 | || (_| |   < (_| |\ V  V /| | |  | |
  \__\__,_|_|\_\__,_| \_/\_/ |_|_|  |_|  ** UNDER DEVELOPMENT **

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# Background

The current generation of RetroForth did not start off as a
traditional, interactive Forth. A minimal (and lightly expanded)
REPL simply called the listener has existed, but it is not a
user friendly system.

Takawiri is a new listener. I've been slowly working on it,
with a goal of growing it into something useful. At present it
is functional, but many pieces remain. (See the end of this
document for a partial list).

# The Interface

Takawiri presents a fullscreen interface. This has a large area
for the display (the "text output buffer", or TOB) with a set
of introspection views on the right. At the bottom is the text
input area.

  +-----------------------------------------+----------------+
  | Text Output Buffer                      | Introspection  |
  |                                         |                |
  |                                         |                |
  |                                         +----------------+
  |                                         | Stack Display  |
  |                                         |                |
  |                                         |                |
  |                                         +----------------+
  |                                         | String Preview |
  |                                         |                |
  |                                         |                |
  |                                         +----------------+
  |                                         | Watched Vars   |
  |                                         |                |
  |                                         |                |
  +-----------------------------------------+----------------+
  | input area                                               |
  +----------------------------------------------------------+

# Startup & Dependencies

Takawiri requires RetroForth 2024.9 or newer, with the ioctl
device enabled. It also requires a terminal with 100 or more
columns and at least 27 rows.

I do the initial configuration, and check these, reporting any
errors and exiting if necessary.

~~~
@Version #202409 lt?
  [ 'Requires_RetroForth_2024.9_or_newer s:put nl bye ] if
~~~

Setup the local terminal dimensions. This uses the `ioctl:`
words added in RetroForth 2024.9.

~~~
ioctl:term-size (rows,cols) 'LT:W const 'LT:H const

LT:W #100 lt? [ 'Terminal_too_narrow! s:put nl bye ] if
LT:H #27 lt?  [ 'Terminal_too_short!  s:put nl bye ] if
~~~

Setup the text output buffer dimensions. The width is currently
fixed at 80 columns; the height is set based on the terminal
height.

~~~
#80       'TOB:W const (:-n)
LT:H #2 - 'TOB:H const (:-n)
~~~

Load dependencies from the library.

~~~
{ 'konilo 'termina 'tob } &library:load a:for-each
~~~

# Configure UI Colors

~~~
:dss:label  (:-) fg:red  ;
:dss:value  (:-) fg:yellow ;
:dss:sep    (:-) fg:cyan ;
:dss:prompt (:-) bg:blue fg:white ;
~~~

# Utilities

I intend for takawiri to provide a variety of useful tools to
aid in using RetroForth interactively.

~~~
:,stack (:s-) d:lookup d:stack fetch s:put nl ;
~~~

# UI

First are words to display the text output buffer.

~~~
:bar:right   (:-) dss:sep TOB:H n:inc [ I n:inc TOB:W #2 n:add vt:row,col $| c:put ] indexed-times vt:reset ;
:bar:bottom  (:-) dss:sep TOB:H n:inc #1 vt:row,col TOB:W n:inc [ $= c:put ] times $+ c:put vt:reset ;
:display:tob (:-) tob:display bar:right bar:bottom ;
~~~

Draw the section separators.

~~~
:length (:-n) LT:W TOB:W #4 n:add n:sub ;
:---    (:n-) [ $- c:put ] times sp ;
:sections (:-)
  dss:sep
  #3 [ I n:inc #6 n:mul TOB:W #4 n:add vt:row,col length --- ]
  indexed-times
  vt:reset ;
~~~

~~~
'Items d:create #0 comma #32 allot

:tos? (:nm-nmf) over n:zero? ;
:dss (:-)
  [ depth #5 n:min !Items
  &Items fetch-next &store-next times drop
  &Items a:reverse [ ] a:for-each
  #0 &Items [
  over n:inc #6 n:add #84 vt:row,col
  dss:label
  tos? [ 'TOS:___ s:put ] [ '_______ s:put ] choose
  vt:reset
  n:put
  n:inc ] a:for-each
  drop ] gc ;
~~~

## String Preview

This is the start of code to display temporary strings on the
data stack. The plan is to have it show below the stack values,
in a format like:

  <depth> <first XX characters>

The <depth> data will match up to the values in the stack disp.

Note: this won't be useful until after the alternate `s:evaluate`
is done.

~~~
{{
  :string? (v-vf) dup STRINGS gt? ;

  :display
    over n:inc #12 n:add #84 vt:row,col
    fg:red
    tos? [ 'TOS:___ s:put ] [ '_______ s:put ] choose
    vt:reset
    s:put ;

  :not-string
    over n:inc #12 n:add #84 vt:row,col
    fg:blue '_______n/a s:put drop vt:reset ;
---reveal---
  :strings (:-)
    #0 &Items [ string? &display &not-string choose n:inc  ]
    a:for-each drop ;
}}
~~~

~~~
:layout:stat,col (:-n) #84 ;
:layout:stat     (:sn-) layout:stat,col vt:row,col dss:label s:put dss:value ;

:stats (:-)
  'HERE:__ #1 layout:stat here n:put
  'FREE:__ #2 layout:stat FREE n:put
  'DEPTH:_ #3 layout:stat depth n:put
  'ROW:___ #4 layout:stat @TY n:put
  'COL:___ #5 layout:stat @TX n:put
  vt:reset
;

:prompt (:-)
  dss:prompt
  LT:H #1 vt:row,col LT:W [ sp ] times
  LT:H #1 vt:row,col '>>_ s:put ;
~~~

~~~
:quit (:-) ioctl:set-lbreak vt:reset bye ;
:bye  (:-) quit ;
~~~

# Watchlist

The watchlist will allow monitoring a small number of addresses
in the right panel of the interface. A use case might be to
do something like:

    &Base 'Base watch
    &Compiler 'Compiler watch

~~~
'Watchlist       d:create #5 , #-1 , #-1 , #-1 , #-1 , #-1 ,
'WatchlistLabels d:create #5 , #-1 , #-1 , #-1 , #-1 , #-1 ,

:watchlist:find (:a-n)
  dup &Watchlist a:contains? [ drop #-1 ] -if;
  &Watchlist swap a:index ;

:watchlist:make-label (:s-s)
  dup s:length #8 gt? [ #8 s:left ] if
  dup s:length #8 lt?
    [ dup s:length #8 swap n:sub [ '_ s:append ] times ] if
  s:keep ;

:watch (:as-)
  watchlist:make-label
  #-1 watchlist:find &Watchlist &WatchlistLabels
  'abcde 'adcbec reorder a:store a:store ;

:unwatch (:a-)
  watchlist:find dup n:positive? &drop -if
  [ &Watchlist       #-1 'abc 'acab reorder a:store ]
  [ &WatchlistLabels #-1 'abc 'acab reorder a:store ] bi ;

:watchlist (:-)
  #19 #5 [ dup #84 vt:row,col
        dss:label &WatchlistLabels over #19 n:sub a:fetch
          dup #-1 -eq? [ s:put sp ] [ drop '_________ s:put ] choose
        dss:value &Watchlist over #19 n:sub a:fetch
        dup n:positive? [ fetch ] [ drop #0 ] choose
        n:put n:inc vt:reset ] times drop ;
~~~

~~~
:ui (:-)
  &err:notfound unhook
  ioctl:set-cbreak
  &banner tob:with
  [ vt:reset vt:clear vt:home
    display:tob
    sections
    stats dss strings watchlist
    prompt s:get-word vt:reset
    [ dup s:put sp interpret ] tob:with
 ] forever ;

ui
~~~

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Things needed:

- termios device & words (or add termios to unix device?)
- colors for interface elements
- refactor & document everything
- line editing

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