stache
Mustache templates for Haskell
https://github.com/stackbuilders/stache
| Version on this page: | 2.1.0@rev:2 |
| LTS Haskell 24.16: | 2.3.4@rev:5 |
| Stackage Nightly 2025-10-25: | 2.3.4@rev:5 |
| Latest on Hackage: | 2.3.4@rev:5 |
stache-2.1.0@sha256:f05a34d83da6bd0989e7ab199e280b0291b40ae05461f82239df5c8cb0f0eb6f,4957Module documentation for 2.1.0
Stache
This is a Haskell implementation of Mustache templates. The implementation conforms to the version 1.1.3 of the official Mustache specification. It is extremely simple and straightforward to use with minimal but complete API—three functions to compile templates (from directory, from file, and from lazy text) and one to render them.
The implementation uses the Megaparsec parsing library to parse the templates which results in superior quality of error messages.
For rendering you only need to create Aeson’s Value where you put the data
to interpolate. Since the library re-uses Aeson’s instances and most data
types in the Haskell ecosystem are instances of classes like
Data.Aeson.ToJSON, the whole process is very simple for the end user.
Template Haskell helpers for compilation of templates at compile time are
available in the Text.Mustache.Compile.TH module. The helpers currently
work only with GHC 8 and later.
One feature that is not currently supported is lambdas. The feature is marked as optional in the spec and can be emulated via processing of parsed template representation. The decision to drop lambdas is intentional, for the sake of simplicity and better integration with Aeson.
Quick start
Here is an example of basic usage:
{-# LANGUAGE OverloadedStrings #-}
module Main (main) where
import Data.Aeson
import Data.Text
import Text.Megaparsec
import Text.Mustache
import qualified Data.Text.Lazy.IO as TIO
main :: IO ()
main = do
let res = compileMustacheText "foo"
"Hi, {{name}}! You have:\n{{#things}}\n * {{.}}\n{{/things}}\n"
case res of
Left bundle -> putStrLn (errorBundlePretty bundle)
Right template -> TIO.putStr $ renderMustache template $ object
[ "name" .= ("John" :: Text)
, "things" .= ["pen" :: Text, "candle", "egg"]
]
If I run the program, it prints the following:
Hi, John! You have:
* pen
* candle
* egg
For more information about Mustache templates the following links may be helpful:
- The official Mustache site: https://mustache.github.io/
- The manual: https://mustache.github.io/mustache.5.html
- The specification: https://github.com/mustache/spec
- Stack Builders Stache tutorial: https://www.stackbuilders.com/tutorials/haskell/mustache-templates/
Contribution
Issues, bugs, and questions may be reported in the GitHub issue tracker for this project.
Pull requests are also welcome and will be reviewed quickly.
License
Copyright © 2016–present Stack Builders
Distributed under BSD 3 clause license.