highlightjs-daml

A Highlight.js language plugin that adds rich syntax highlighting for DAML — the smart contract language developed by Digital Asset for building multi-party workflows on distributed ledgers.

Features

• Full keyword coverage: template, choice, interface, signatory, observer, controller, with, where, do, and all standard Haskell-style keywords
• Template, interface, and exception declarations with class name highlighting
• Choice declarations highlighted as function titles
• Module and import directives highlighted as meta
• DAML/Haskell pragmas ({-# OPTIONS_GHC … #-})
• Built-in types and functions: Party, ContractId, Text, Decimal, create, exercise, fetch, archive, and more
• Literals: True, False, None, Some
• Haskell-style line (--) and block ({- … -}) comments
• Numeric literals with underscore separators (1_000_000)
• Haskell-style character literals ('a', '\n')
• Type names highlighted as type
• Infix operators in backticks (`elem`)
• Standard and Haskell-specific operators (->, <-, =>, ::, \, …)
• Correct auto-detection: DAML templates reliably identified via highlightAuto

Installation

npm install highlightjs-daml

highlight.js ≥ 11 is a peer dependency — install it separately if you haven't already:

npm install highlight.js

Usage

CommonJS / Node.js

const hljs = require("highlight.js");
const daml = require("highlightjs-daml");

hljs.registerLanguage("daml", daml.default ?? daml);

const code = `
template Iou
  with
    issuer : Party
    owner  : Party
    amount : Decimal
  where
    signatory issuer
    observer owner

    choice Transfer : ContractId Iou
      with newOwner : Party
      controller owner
      do
        create this with owner = newOwner
`.trim();

const html = hljs.highlight(code, { language: "daml" }).value;
console.log(html);

ES Modules

import hljs from "highlight.js";
import daml from "highlightjs-daml";

hljs.registerLanguage("daml", daml);

const result = hljs.highlight(code, { language: "daml" });

Browser (CDN)

Load Highlight.js first, then load this plugin:

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.10.0/styles/github-dark.min.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.10.0/highlight.min.js"></script>
<!-- highlightjs-daml -->
<script src="https://unpkg.com/highlightjs-daml/dist/index.js"></script>
<script>
  hljs.registerLanguage("daml", window.hljsDaml?.default ?? window.hljsDaml);
  hljs.highlightAll();
</script>

Then mark up your code blocks:

<pre><code class="language-daml">
template Asset
  with
    issuer : Party
    owner  : Party
    name   : Text
  where
    signatory issuer
    observer owner

    choice Give : ContractId Asset
      with newOwner : Party
      controller owner
      do create this with owner = newOwner
</code></pre>

Auto-detection

The plugin registers DAML with high-relevance rules on template/choice/signatory constructs so highlightAuto correctly identifies DAML source files:

const result = hljs.highlightAuto(unknownCode);
console.log(result.language); // "daml"

Supported syntax elements

| Element | Highlight class | |---------|----------------| | module, import | hljs-meta | | Pragmas {-# … #-} | hljs-meta | | Keywords (template, choice, signatory, …) | hljs-keyword | | Template / exception / data names | hljs-title class_ | | Choice names | hljs-title function_ | | Built-in types and functions | hljs-built_in | | Type names (uppercase identifiers) | hljs-type | | Literals (True, False, None, Some) | hljs-literal | | String literals | hljs-string | | Character literals | hljs-string | | Numeric literals | hljs-number | | Operators (->, <-, ::, =>, …) | hljs-operator | | Infix in backticks | hljs-operator | | Comments (--, {- … -}) | hljs-comment |

Example

module Finance where

import DA.List (sortOn)

template Iou
  with
    issuer : Party
    owner  : Party
    amount : Decimal
    currency : Text
  where
    signatory issuer
    observer owner

    ensure amount > 0.0

    choice Transfer : ContractId Iou
      with newOwner : Party
      controller owner
      do
        create this with owner = newOwner

    choice Settle : ()
      controller owner
      do
        archive self

interface Token where
  viewtype TokenView
  getOwner : Party
  getAmount : Decimal

Compatibility

| highlight.js | highlightjs-daml | |--------------|-----------------| | ≥ 11.0.0 | ✓ |

License

MIT © ABDK Consulting