fourmi

🐜 A small taskrunner that harnesses the power of Lua's metamethods to easily express flow of tasks.

Note: Fourmi is in active development.

Installation

Requirements:

• Lua 5.3
• luarocks >= 3.0 (Note: hererocks -rlatest will install 2.4, you need to specify it with -r3.0)

luarocks install --server=http://luarocks.org/dev fourmi

Usage

Write a fourmi.plan.lua file in your project directory and then:

# If `plan` is not provided, will run plan named `all`
fourmi [--file <file>] [-h] <plan> [<arguments>] ...

Task

Task are relatively small jobs that you can combine using operators.

local mytask = task "mytask"
    :description "A short description of what it does"
    :file "output.o"
    :requires { "file1.x", "file2.x" }
    :property("propertykey", propertyvalue)
    :perform(function(self, ...)
        -- Do something with ...

        return output1, ..., ouputn
    end)

Operators

• task1 .. task2: returns a new task that does task1 then task2
• task1 & task2: returns a new task that does task2 has output, pipes it to task2
• task1 | task2: returns a new task that does task2 only if task1 returns falsy value
• task1 >> task2: returns a new task that pipes task1 into task2
• task1 * task2: returns a new task that does task2 for all output of task1
• task1 ^ (condition): returns a new task that does task1 if condition (expression or function to be evaluated) is true

Here's an commented excerpt of fourmi.plan.lua:

-- Define variables
-- Those can be overwritten with cli arguments of the form `key=value`
var {
    min  = "luamin",
    src  = "./fourmi",
    dest = "~/tmp-code",
}

-- ...

return {
    -- Default plan
    plan "all"
        -- Small description of what the plan does
        :description "Minify and gzip lua files"
        -- Define its task
        :task(
            -- List files in `./fourmi` ending with `.lua`
            ls("@{src}", "%.lua$")
                -- For each of them: if the gzipped file does not exist or is older than the original,
                -- minify then gzip then move to `~/tmp-code`
                * (outdated "@{dest}/#{original}.gz"
                    & minify >> gzip >> mv "@{dest}")
        ),

    -- Clean plan
    plan "clean"
        :description "Cleanup"
        :task(
            -- Remove all files from `~/tmp-code`
            empty "@{dest}"
        )
}

If you don't want to use operators, you can use their aliases:

• ..: after
• &: success
• |: failure
• >>: into
• *: each
• ^: meet

__ function

__(string, [context]) interpolates special special sequences in a string:

• ~: will be replaced with $HOME
• ${ENV}: will be replaced by the ENV environment variable
• #{variable}: fourmi will look for variable in context or _G if none provided
• @{fourmi_variable}: will be replaced by the fourmi_variable defined with var(name, value)