XS - Programming language

XS is a programming language created in 2002.

#1030on PLDB

22Years Old

532Repos

XS is a Perl foreign function interface through which a program can call a C or C++ subroutine. XS or xsub is an abbreviation of "eXternal Subroutine", where external refers to programming languages external to Perl. XS also refers to a glue language for specifying calling interfaces supporting such interfaces (see below).. Read more on Wikipedia...

Tags: programming language
There are at least 532 XS repos on GitHub
The Google BigQuery Public Dataset GitHub snapshot shows 2k users using XS in 2k repos on GitHub
Explore XS snippets on Rosetta Code
GitHub supports syntax highlighting for XS
See also: (3 related languages) Perl, C, Pod

Example from Linguist:

/*
 * This software is copyright (C) by Nick Wellnhofer <wellnhofer@aevum.de>.
 *
 * This is free software; you can redistribute it and/or modify it under
 * the same terms as the Perl 5 programming language system itself.
 *
 * Terms of the Perl programming language system itself
 *
 * a) the GNU General Public License as published by the Free
 *    Software Foundation; either version 1, or (at your option) any
 *    later version, or
 * b) the "Artistic License"
 */

/*
 * Notes on memory management
 *
 * - A pointer to the Perl SV representing a node is stored in the
 *   user data slot of `struct cmark_node`, so there's a 1:1 mapping
 *   between Perl and C objects.
 * - Every node SV keeps a reference to the parent SV. This is done
 *   indirectly by looking up the parent SV and increasing its refcount.
 * - This makes sure that a document isn't freed if the last reference
 *   from Perl to the root node is dropped, as references to child nodes
 *   might still exist.
 * - As a consequence, as long as a node is referenced from Perl, all its
 *   ancestor nodes will also be associated with a Perl object.
 */

#define PERL_NO_GET_CONTEXT

#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

#include <stdlib.h>
#include <cmark.h>

#if CMARK_VERSION < 0x001000
    #error libcmark 0.16.0 is required.
#endif

/* Fix prefixes of render functions. */
#define cmark_node_render_html cmark_render_html
#define cmark_node_render_xml  cmark_render_xml
#define cmark_node_render_man  cmark_render_man

static SV*
S_create_or_incref_node_sv(pTHX_ cmark_node *node) {
    SV *new_obj = NULL;

    while (node) {
        SV *obj;
        HV *stash;

        /* Look for existing object. */
        obj = (SV*)cmark_node_get_user_data(node);

        if (obj) {
            /* Incref if found. */
            SvREFCNT_inc_simple_void_NN(obj);
            if (!new_obj) {
                new_obj = obj;
            }
            break;
        }

        /* Create a new SV. */
        o

Language features

Feature	Supported	Example	Token
Comments	✓	/* A comment */
MultiLine Comments	✓	/* A comment */	/* */
Semantic Indentation	X