Custom functions

[f-w]

The function expression grammar and built-in functions give me the impression that custom function is supported. However, there is no docs on how to create a custom function. Does it vary by language-specific library? Please clarify. I use jmespath.js.

This feature is important to me because built-in functions seem lacking some basic features, for example case sensitivity option for string matching functions such as contains.

[cs-christopher-carsey]

I second this. Recently noticed the lack of case sensitivity option as well and would like to add a lower() function to functional expressions (e.g. [?lower(foo) == 'bar']).

[f-w]

@carsey, if you use jmespath.js, I got custom function working successfully in my fork. I submitted a PR but author didn't respond.