Parameters

Parameters are defined with a function header like syntax. Let's take a look at the "Hello World" example from here.

hello-world(location l: arg) {
    action <% echo Hello World from $(location) %>
}

As you can see, our root toolchain supports a parameter, location that you can then reference in your action templates and even constants.

We also defined a shorthand, l for our parameter.

Declare more than one parameter by separating them with a comma (,)

Types

Currently, 2 types are supported:

arg - a normal string value
flag - a boolean value that is set to true if passed and set to false if omitted

Scope

The params that you define for a toolchain can be referenced in any descendant toolchain.

scope.cli
hello-world(location l: arg) {
    action <% echo Hello World from $(location) %>

    sub child {
        action <% echo Hello Child from $(location) %>
    }
}

$ hello-world Cluj-Napoca
Hello World from Cluj-Napoca

$ hello-world Cluj-Napoca child
Hello Child from Cluj-Napoca

Optionals

Optional arguments will not be mandatory when the toolchain is executed.

If a value is not passed for an optional, it will default to empty string in case of an arg Flags are optional by default and their default value is false

They are marked with the question mark (?) character at the end of their name. When a parameter is optional, it is no longer passed in as a positional argument. You will need to specify its name before the value.

optionals.cli
hello-world(location l: arg?) {
    action <% echo Hello World from $(location) %>
}

$ hello-world 
Hello World from

$ hello-world --location Cluj-Napoca
Hello World from Cluj-Napoca

Defaults

Defaults are only supported for optional params.

defaults.cli
hello-world(location l: arg? = "the other side") {
    action <% echo Hello World from $(location) %>
}

$ hello-world 
Hello World from the other side

$ hello-world -l Cluj-Napoca
Hello World from Cluj-Napoca