Variables

Defining a variable in Werk is a let-statement. Values are either strings or lists (no numbers). Lists may contain other lists. All strings are valid UTF-8.

Syntax: let identifier = expression. The left-hand side of the = must be a valid identifier (Unicode is supported), and the right-hand side is any expression. All expressions produce a value.

let my-string = "value"

let my-list = ["a", "b", "c"]

All variables are immutable, but variable names may shadow local or global variables with the same name.

let foo = "a"
let foo = "b"   # valid

let bar = foo   # == "b"

Config variables are public

Variables defined with the config keyword instead of let at the global scope (i.e., outside of any recipe) are public, and will appear in the output of werk --list. They can be overridden by passing -Dkey=value on the command-line. Comments immediately preceding a global variable will appear in the output as documentation for that variable.

# Set the build profile.
config profile = "debug"

$ werk --list
Config variables:
    profile = "debug" # Set the build profile.

Local variables

Variables defined within a recipe are local to that recipe. Recipes cannot change global variables, but they may shadow global variables in their local scope by defining a variable with the same name as a global variable.