abdk-highlightjs-huff

A Highlight.js language plugin that adds rich syntax highlighting for Huff — the low-level EVM assembly language for writing highly optimised Ethereum smart contracts.

Features

• All #define variants highlighted: macro, fn, test, function, event, error, constant, jumptable, jumptable__packed, table
• Definition names highlighted as title.function
• takes / returns stack-annotation keywords
• Function modifiers: view, pure, payable, nonpayable, indexed
• FREE_STORAGE_POINTER keyword
• Complete EVM opcode set (including Cancun: tload, tstore, mcopy, blobhash, blobbasefee)
• Compiler built-in functions: __FUNC_SIG, __EVENT_HASH, __ERROR, __RIGHTPAD, __codesize, __tablestart, __tablesize
• Constant references [NAME] highlighted as variable
• Macro argument invocations <name> highlighted as variable
• Label definitions (label:) highlighted as symbol
• Test decorators (#[calldata(...), value(...)])
• #include paths highlighted as strings
• Decimal and hexadecimal numeric literals
• Line and block comments
• Reliable auto-detection via highlightAuto

Installation

npm install abdk-highlightjs-huff

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 huff = require("abdk-highlightjs-huff");

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

const code = `
#define macro MAIN() = takes (0) returns (0) {
    0x00 calldataload
    0xE0 shr
    __FUNC_SIG(transfer) eq transfer jumpi
    0x00 0x00 revert
    transfer:
        0x01 0x00 mstore
        0x20 0x00 return
}
`.trim();

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

ES Modules

import hljs from "highlight.js";
import huff from "abdk-highlightjs-huff";

hljs.registerLanguage("huff", huff);

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

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>
<!-- abdk-highlightjs-huff -->
<script src="https://unpkg.com/abdk-highlightjs-huff/dist/index.js"></script>
<script>
  hljs.registerLanguage("huff", window.hljsHuff?.default ?? window.hljsHuff);
  hljs.highlightAll();
</script>

Then mark up your code blocks:

<pre><code class="language-huff">
#define macro MAIN() = takes (0) returns (0) {
    0x00 calldataload 0xE0 shr
    __FUNC_SIG(transfer) eq transfer jumpi
    0x00 0x00 revert
    transfer:
        0x04 calldataload
        0x24 calldataload
        TRANSFER()
        0x20 0x00 return
}
</code></pre>

Auto-detection

The plugin registers Huff with high relevance scores on #define directives and built-in functions so highlightAuto correctly identifies Huff source files:

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

Supported syntax elements

| Element | Highlight class | |---------|----------------| | #define, #include, #[…] decorator | hljs-meta | | Definition types (macro, fn, test, …) | hljs-keyword | | takes, returns, modifiers | hljs-keyword | | FREE_STORAGE_POINTER | hljs-keyword | | Definition names | hljs-title function_ | | EVM opcodes | hljs-built_in | | Compiler built-ins (__FUNC_SIG, …) | hljs-built_in | | Constant references [NAME] | hljs-variable | | Macro argument invocations <name> | hljs-variable | | Label definitions (label:) | hljs-symbol | | Numeric literals | hljs-number | | String literals | hljs-string | | Comments | hljs-comment |

Example

#include "huffmate/auth/Owned.huff"

#define function transfer(address, uint256) nonpayable returns (bool)
#define event Transfer(address indexed, address indexed, uint256)
#define error InsufficientBalance(uint256, uint256)

#define constant BALANCE_SLOT = FREE_STORAGE_POINTER()

#define macro TRANSFER() = takes (2) returns (0) {
    // Input stack: [to, amount]
    caller                    // [from, to, amount]
    dup3                      // [amount, from, to, amount]
    [BALANCE_SLOT] sload      // [balance, amount, from, to, amount]
    dup2 dup2 lt              // [balance < amount, balance, amount, from, to, amount]
    insufficient jumpi        // [balance, amount, from, to, amount]

    sub                       // [new_balance, from, to, amount]
    caller [BALANCE_SLOT] sstore   // [from, to, amount]

    // emit Transfer(from, to, amount)
    __EVENT_HASH(Transfer)
    0x00 0x00 log3

    stop

    insufficient:
        __ERROR(InsufficientBalance)
        0x00 mstore
        0x24 0x00 revert
}

License

MIT © ABDK Consulting