Naked variable markup

[tmedwards]

Improve the naked variable markup's ability to match variable property chains.

[Uzume]

That would work better if the variables were denoted with more than just a leading sigil. For example in Bourne shells they use similar prefixes but also allow optional curly brace quoting to denote the begin and end allowing such variables to be abutted with other text without parsing issues.

Much like in #18 I would like to have a way to turn naked variables "off" (<<=>>, <<->> and <<print>> work just fine as does writing to output in <<script>>, etc.). Or even better yet have them default to "off" and have a config option to turn them "on". Regardless, when they are "on", improvements to the markup is welcome.

Might I recommend a syntax inspired by the newer Python and .NET (C#) string formatting work?

• https://docs.python.org/3/library/string.html#formatstrings
• https://docs.microsoft.com/en-us/dotnet/api/system.string.format#Starting