hcl/ext/userfunc/README.md

zcl User Functions Extension

This zcl extension allows a calling application to support user-defined functions.

Functions are defined via a specific block type, like this:

function "add" {
  params = ["a", "b"]
  result = a + b
}

The extension is implemented as a pre-processor for cty.Body objects. Given a body that may contain functions, the DecodeUserFunctions function searches for blocks that define functions and returns a functions map suitable for inclusion in a hcl.EvalContext. It also returns a new cty.Body that contains the remainder of the content from the given body, allowing for further processing of remaining content.

For more information, see the godoc reference.