• From: "Liam R. E. Quin" <liam@f...>
• To: Roger L Costello <costello@m...>, "xml-dev@l..." <xml-dev@l...>
• Date: Sat, 05 Mar 2022 23:44:22 -0500

On Sat, 2022-03-05 at 23:02 +0000, Roger L Costello wrote:
> Hi Folks,
> 
> Consider the C language. It is one language. It doesn't use (host)
> other languages. 

Well, this is rather debatable.

Firs,t there's the C pre-processor, which is a different language.

#ifdef SOMETHING
#  ifdef SOMETHING_ELSE
. . .
#  endif SOMETHING_ELSE
#else SOMETHING
. . . .
#endif SOMETHING

(the tokens on else and endif were originally ignored and written like
that by convention; i once suggested something similar for XML, e.g.
  </div id="percy">
where the id attribute has to match the one in the start tag, for the
same reason - extra error checking.

C also has regular expressions in the standard library; originally
these were system-dependent extensions, and POSIX standardized them.

If you search for domain specific language (DSL), you'll find a ton of
them for different applications; it's quite common.  Often, i refer to
XPath as a DSL for tree-structured data such as one might interchange
with XML.

Liam


-- 
Liam Quin, https://www.delightfulcomputing.com/
Available for XML/Document/Information Architecture/XSLT/
XSL/XQuery/Web/Text Processing/A11Y training, work & consulting.
Barefoot Web-slave, antique illustrations:  http://www.fromoldbooks.org

• Follow-Ups:
  • Re: Are multi-language languages unique to the XML familyof languages?
    • From: Michael Kay <mike@s...>

• References:
  • Are multi-language languages unique to the XML family of languages?
    • From: Roger L Costello <costello@m...>