Elm Extensions

A type-safe string formatting library. Fulfils the need for string-interpolation or a printf function, without sacrificing Elm's runtime guarantees.

Installation

From your top-level directory - the one with elm-package.json in - call:

$ elm package install krisajenkins/formatting

Usage

We want to display something like "Hello <name>!". It consist of:

A boilerplate string, "Hello "
A "hole" for a String
Another boilerplate string, "!"

To create that, we'll build up a formatter using s for boilerplate strings, string for the hole, and <> to join them together:

import Formatting exposing (..)

greeting =
    s "Hello " <> string <> s "!"

Now we print with that formatter, and its arguments:

print greeting "Kris"

--> "Hello Kris!"

Now let's try to call that formatter with bad arguments:

print greeting 5

-- TYPE MISMATCH ---------------------------------------------
The 2nd argument to function `print` is causing a mismatch.

4|   print greeting 5
                    ^
Function `print` is expecting the 2nd argument to be:

    String

But it is:

    number

Woo - it's like printf, but it can't blow up at runtime.

Documentation

See the Elm package for full usage docs.

Status

In active development. The hard part is done, but we need more utility functions.

API subject to change.

Building & Testing

make

...will run the whole build and test suite.

License

Distributed under the MIT license.

krisajenkins/formatting/1.0.0