mustache-haskell

A Haskell implementation of mustache templates. Expects input data to be JSON.

Should be compatible with the the mustache specification. Except lambdas are not supported.

Supported syntax:

• basic variables
• sections
• inverted sections
• comments (are suppressed)
• partials
• set delimiter

This project currently only provides a command line interface. Later versions will provide a library API for templating ToJSON instances.

Install

You need the Haskell platform on your system.

cabal install mustache-haskell

Or alternatively

git clone git@github.com:danchoi/mustache-haskell.git
cd mustache-haskell
cabal sandbox init
cabal install
# Now copy .cabal-sandbox/bin/mus to your PATH

Usage

mus template.mustache < input.json

mus 
Usage: mus [-c] [-d TEMPLATE_DIRECTORY] TEMPLATE_FILE
  A Haskell implementation of Mustache templates. On STDIN provide the JSON to
  insert into the template.
Available options:
  -h,--help                Show this help text
  -c                       Just output parse tree of template file
  -d TEMPLATE_DIRECTORY    Template directory

List separator syntax

mustache-haskell adds one additional feature to the mustache specification. If you are outputing elements of a list, you can designate an optional list separator with the following syntax:

{{#hobbies, }}{{name}}{{/hobbies}}

This designates ", " as the list separator and will output

sewing, brewing, cooking

when the input is

{"hobbies":[{"name":"sewing"},{"name":"brewing"},{"name":"cooking"}]}

Performance

In a few informal tests,

mus template.mustache < input.json

is about 10x faster than the Ruby mustache gem command-line implementation,

mustache - template.mustache < input.json

Related projects

• whiskers Mustache templates with Template Haskell (reddit)
• hastache Haskell implementation of Mustache templates
• mustache2hs takes in Haskell records (single data constructor only) and a list of mustache template and record name pairs, and generates Haskell code for functions that take an escape function and one of the records
• mustache.go an implementation of the mustache template language in Go