TeLML

A Tex-Like Markup Language—which is a bit of a misnomer, because as presented, it's more of a structured data language optimized for text documents than an actual markup language. A markup-oriented use of this library can be found in the telml-markup package.

A TeLML Document is a sequence of textual fragments interspersed with "tags", which have the format

\tagname{ document | document | ... }

Whitespace is not allowed between the backslash and the tag name, but is allowed between the tag name and the following block. This means that the following is allowed:

\tag
  { element_1
  | element_2
  | ...
  | element_n
  }

In contrast to TeX, the block is obligatory, i.e. the following is not a valid document:

\p{this \br and that}

Whereas this is:

\p{this \br{} and that}

(This restriction might at some point be lifted based on experience with the format.)

The intended use for TeLML is as a building-block for specific markup formats in which you might want to have arbitrary new tags, but don't want to use an XML-based solution.

Formal Grammar

<document> ::= <fragment>*
<fragment> ::= <tag> | <text> | "{" <document> "}"

<text>     ::= /([^\]|[\][\{}|])*/

<tag>      ::= "\" <tagname> <spaces> "{" <arglist> "}"
<tagname>  ::= /[A-Za-z][A-Za-z0-9_-]*/
<arglist>  ::= <document> ("|" <document>)*
<spaces>   ::= /[ \t\r\n]*/

Possible Future Modifications

Variations on this theme that might be possible:

• It might (as stated above) be worthwhile to attempt to lift the restriction that every tag has an argument block, if nullary tags are commonly used.
• It might be nice to optionally allow \begin{...} and \end{...} tags to be parsed as a special case of certain delimiters.
• Maybe a special case for named arguments of the form \tag{arg=stuff|arg=stuff}, although this could be handled at present by using nested tags as in \tag{\arg{stuff}|\arg{stuff}}.