ArcScript Language Support

Syntax highlighting, code snippets, and language features for ArcScript (.arc files) — the visual novel scripting language for browser-based interactive stories.

Features

Syntax Highlighting

Full token-level highlighting for every ArcScript construct:

Code Snippets

Type a prefix and press Tab to expand:

Language Features

• Auto-closing pairs — {, [, (, " auto-close
• Auto-indentation — indent increases after ~if, ~define, ~func, etc.; decreases at ~end, ~elif, ~else
• Code folding — knots, ~define blocks, ~func blocks, and ~triggers blocks fold cleanly
• Comment toggling — Ctrl+/ toggles // line comments

Installation

Option A — Install the .vsix Directly (Recommended)

1. Build the package: npm run package (requires Node.js)
2. In VS Code: Extensions → … → Install from VSIX… → select arcscript-1.0.0.vsix
3. In Visual Studio 2022+: Extensions → Manage Extensions → … → Install from VSIX

Option B — Development / Sideload (VS Code)

1. Copy this folder into %USERPROFILE%\.vscode\extensions\arcscript-1.0.0\
2. Restart VS Code — .arc files will immediately use ArcScript syntax

Option C — Visual Studio 2022 (TextMate Grammar Only)

Visual Studio 2022 16.6+ natively supports TextMate grammars. To use without packaging:

1. Install the TextMate Bundles extension for Visual Studio
2. Copy syntaxes/arcscript.tmLanguage.json into your Visual Studio TextMate bundle directory
3. Associate .arc files with the source.arc scope in VS options

Color Theme Compatibility

The grammar uses standard TextMate scopes, so it works well with most popular themes:

File Structure

arcscript-vsx/
├── package.json                  ← Extension manifest
├── language-configuration.json   ← Bracket matching, folding, indentation
├── .vscodeignore
├── README.md
├── syntaxes/
│   └── arcscript.tmLanguage.json ← TextMate grammar (core syntax rules)
└── snippets/
    └── arcscript.code-snippets   ← ~45 code snippets

Quick ArcScript Reference

// Comments — ignored by compiler
## Also a comment (preferred for section headers)

=== knot_name ===        // Scene (knot) definition — compiler starts at the first knot
= stitch_name            // Sub-section within a knot

CONST MAX = 100          // Compile-time constant
VAR score: int = 0       // Runtime variable (optional type annotation)
~set score = score + 10  // Update a variable

-> other_knot            // Jump to a knot
-> knot.stitch           // Jump to a specific stitch
-> END                   // End the story
-> MENU                  // Enter sandbox exploration mode

* [Choice text] Story text   // Once-choice (disappears after selection)
+ [Always choice]            // Always-choice
* {condition} [Guarded]      // Conditional choice
-                            // Gather — convergence after choices

~if (expr)               // Conditional block
~elif (expr)
~unknown                 // Ternary Unknown branch
~else
~end

~when (expr) … ~end      // Single-branch if
~unless (expr) … ~end    // Runs when false

Speaker: Dialogue text   // Single speaker line
::speaker_id             // Open speaker block
All lines attributed.
::                       // Close speaker block

%background% path %transition% fade %duration% 1.5
%character% id %sprite% name %pos% left %enter% slide_in
%audio% path %channel% bgm %loop% %volume% 0.4
%effect% screen_shake %intensity% 0.5 %duration% 0.4
%video% path.mp4 %skip_after% 3
%popup% "Message" %duration% 3.0
%minigame% lockpick %difficulty% 2 %result_var% result_var

~define char "id" … ~end
~define place "id" … ~end
~define object "id" … ~end
~triggers … ~end
~recipes … ~end
~func verb_examine(target) -> _result … ~end

any(coll, it.field > 0)
all(coll, it.sealed == True)
count(coll, it.health > 0)
visits(knot_name)

~wait 1.5
~log "debug: {var}"
~assert (cond) "message"
INCLUDE "path/to/file.arc"