#!/usr/bin/env retro

# retro-describe

This is a small tool to display some helpful information
about a word.

# Usage

    retro-describe wordname

# Notes

This is based on the `glossary.forth` tool included with
Retro. It's basically just the `describe` functionality,
but is a little more streamlined to use and abandons the
editing and export functionality of the full tool.

# The Code

First, gather the command line arguments. If no word name
was passed, just exit.

~~~
script:arguments n:zero? [ #0 unix:exit ] if
~~~

~~~
#166 'DATA-START const
~~~

# Data File

/usr/local/share/RETRO12/words.tsv

I like plain text formats, so the data is stored as a plain text
file, with one line per word. Each line has a number of fields.
These are tab separated. The fields are:

    | name                       | 0
    | data stack                 | 1
    | address stack              | 2
    | float stack                | 3
    | general description        | 4
    | interpret time description | 5
    | compile time description   | 6
    | class handler              | 7
    | example 1                  | 8
    | example 2                  | 9
    | namespace                  | 10
    | interface                  | 11

I use a variable named `SourceLine` to point to the current line
contents.

~~~
'SourceLine var
~~~

I next define words to access each field. This involves helpers
to skip over fields I'm not intersted in, a word to return a 
specific field, and the top level wrappers over these.

Rather than manually enter each of the field accessors, I am
just listing them in a set and constructing the words via some
simple code.

~~~
{{

  :select @SourceLine ASCII:HT s:tokenize swap a:fetch ;

---reveal---

  #0 { 'name        'dstack     'astack     'fstack
       'descr       'itime      'ctime      'class
       'ex1         'ex2        'namespace  'interface }

  [ 'field: s:prepend d:create
    dup compile:lit &select compile:call compile:ret
    &class:word reclass n:inc ] a:for-each drop
}}
~~~

# Display an Entry

I implement a word to display an entry. This will use a
format like:

    name

      Data:  -
      Addr:  -
      Float: -

    A description of the word.

    Class Handler: class:word | Namespace: global | Interface Layer: all

If there are specific notes on interpret or compile time
actions, or any examples, they will be displayed after
the description.

~~~
{{
  :s:putfmt (s-)   s:format s:put ;
  :name            field:name    '%s\n\n           s:putfmt ;
  :data            field:dstack  '__Data:__%s\n    s:putfmt ;
  :address         field:astack  '__Addr:__%s\n    s:putfmt ;
  :float           field:fstack  '__Float:_%s\n\n  s:putfmt ;
  :description     field:descr   '%s\n\n           s:putfmt ;
  :interpret-time  field:itime s:length 0; drop
                   field:itime   'Interpret_Time:\n__%s\n\n s:putfmt ;
  :compile-time    field:ctime s:length 0; drop
                   field:ctime   'Compile_Time:\n__%s\n\n   s:putfmt ;
  :|                               '_|_ s:put ;
  :class           field:class     'Class:_%s     s:putfmt ;
  :namespace       field:namespace 'Namespace:_%s s:putfmt ;
  :interface       field:interface 'Interface_Layer:_%s s:putfmt ;
  :example1        field:ex1 '{n/a} s:eq? not 0; drop
                   field:ex1 s:format '\nExample_#1:\n\n%s\n\n s:putfmt ;
  :example2        field:ex2 '{n/a} s:eq? not 0; drop
                   field:ex2 s:format '\nExample_#2:\n\n%s\n\n s:putfmt ;
---reveal---
  :display-result
    name
      data    (stack)
      address (stack)
      float   (stack)
    description
    interpret-time
    compile-time
    class | namespace | interface nl
    example1
    example2
    bye ;
}}
~~~

## Describe a Word

~~~
{{
  'Target var
  'LineNumber var
  :matched? (-f) field:name s:hash @Target eq? ;
  :entry?   (-f) @LineNumber DATA-START gteq? &LineNumber v:inc ;
  :process  (-)  &Heap [ s:keep !SourceLine matched? &display-result if ] v:preserve ;
---reveal---
  :find-and-display-entry
    #0 !LineNumber s:hash !Target
    script:name [ entry? &process &drop choose ] file:for-each-line nl ;
}}
~~~

# Finish

This checks the command line arguments and calls the proper words to
handle each case.

~~~
script:arguments [ I script:get-argument find-and-display-entry ] indexed-times
~~~

# Glossary Data