How to properly use the Red/System dialect from the pure Red code?

Question

I am writing a simple tutorial application using curses binding to Red/System. Doing it like it is shown in "curses-example.reds" works great. But how can I use this binding from a pure Red code? Did I get the whole approach wrong and I really must stay within borders of Red/System dialect?

The code is as simple as it could be:

Red/System [
    File:    "%test.reds"
]

#include %curses/curses.reds

with curses [
    initscr
    getch
    endwin
]

How I can properly do a two-way date exchange between Red/System and Red? I did not get it pretty good from the answer to this question.

score 3 · Accepted Answer · answered Feb 05 '15 at 02:19

Currently, to use Red/System Code from a Red program you need to use a routine! - http://www.red-lang.org/search/label/routine

At the moment, only integer! and logic! values can be passed transparently between Red and Red/System. Other datatypes have to be converted, inside the routine, to be usable.

For example, if you have a string! datatype as a parameter of a routine, Red will pass the data to the routine as a red-string! structure:

red-string!: alias struct! [
    header  [integer!]          ;-- cell header
    head    [integer!]          ;-- string's head index (zero-based)
    node    [node!]             ;-- series node pointer
    cache   [c-string!]         ;-- (experimental)
]

It needs to be converted to a Red/System c-string! before you can use it in the routine. At the same time, you must cater for the encoding differences between Red string!s and Red/System c-string!s. A red string! may be ISO-8559-1, UCS-2 or UTF-32 encoded.

You must cater for the opposite if you wish to return a string! to a Red program from a routine.

Other datatypes will need to be handled in similar ways.

I'm sure that passing values between Red and Red/System will be made much, much easier in future. However, I wouldn't personally expect that until after Red reaches version 1.0.

iArnold · Answer 2 · 2017-04-11T10:25:11.087

1

First make your code Red code not Red/System. Next try to stay as close as possible to the examples from the blog on the red-lang.org site. You need to look for routine.

I want to say a special thank you to the person that has voted my answer down.

edited Apr 11 '17 at 10:25

answered Feb 04 '15 at 13:35

iArnold

333
2
10

I was asking assuming that simply changing Red/System to Red in the declaration does not work. – Ivan Sukin Feb 04 '15 at 16:08
Right, that change alone will not cut the deal. I did a video explaining how this works. – iArnold Feb 04 '15 at 19:39

How to properly use the Red/System dialect from the pure Red code?

2 Answers2