GALA Playground

A web-based playground for the GALA programming language, inspired by Go Playground. Write and run GALA code directly in your browser.

Try it live: gala-playground.fly.dev

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Features

• Browser-based code editor with line numbers, tab support, and resizable split panels
• Instant execution -- compile and run GALA code with one click or Ctrl+Enter
• 15 built-in examples covering all major GALA features
• Error display -- compile errors and runtime panics shown inline
• Share -- copy code to clipboard with one click
• Dark theme -- developer-friendly IDE-like interface

Built-in Examples

Example	Features Showcased
Hello	Basic syntax, Println, func main()
Sealed Types	ADTs, exhaustive pattern matching, expression functions
Pattern Matching	Guards, custom extractors (Unapply), type matching
Collections	Array, Filter, Map, FoldLeft, functional pipelines
Option & Either	Some/None, Left/Right, safe null handling, validation
Try Monad	Panic recovery, Map chaining, Recover, GetOrElse
HashMap	Immutable maps, FoldLeft word counter, Sorted, MapValues
Generics	Type parameters, generic structs, generic methods
Roman to Int	String processing, FoldLeft, match on characters
Streams	Lazy evaluation, infinite sequences, Take, Filter, Map
Named Arguments	Default params, named args in any order, Copy overrides
JSON	JsonStringify, JsonParse, Json[T] extractor, Collect
Regex	Capture groups via Unapply + Array destructuring, FindAll
IO Effects	IO[T] monad, Suspend, Map/FlatMap, Recover, AndThen
Tour	Full 10-section showcase with formatted output

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Quick Start

Local

Requires Go 1.25+ and GALA 0.61.1+.

# Install GALA
curl -fsSL -o ~/.local/bin/gala \
  https://github.com/martianoff/gala/releases/latest/download/gala-linux-amd64
chmod +x ~/.local/bin/gala

# Clone and run
git clone https://github.com/martianoff/gala-playground.git
cd gala-playground
gala run .

Opens automatically at http://localhost:3000.

Docker (pre-built)

docker run -p 3000:3000 maxmtmn/gala-playground

Open http://localhost:3000.

Docker (build from source)

docker build -t gala-playground .
docker run -p 3000:3000 gala-playground

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Architecture

gala-playground/
  main.gala          # GALA server (uses gala-server module)
  gala.mod           # GALA module file with dependencies
  static/
    index.html       # Single-page frontend (editor + output)
  examples/
    hello.gala       # 15 pre-loaded GALA examples
    sealed_types.gala
    ...
  Dockerfile         # Multi-stage build (GALA build + runtime)

The server is written entirely in GALA using the gala-server HTTP framework. Static files and examples are embedded at compile time using GALA's embed val directives.

How It Works

1. User writes GALA code in the browser editor
2. Clicking Run (or Ctrl+Enter) sends the code to /api/run
3. The server writes the code to a temp directory with a gala.mod
4. gala run transpiles the GALA code to Go and executes it
5. Output (or errors) are returned and displayed in the output panel

API

Endpoint	Method	Description
/api/run	POST	Execute GALA code. Body: {"code": "..."}. Returns: {"output", "error", "time"}
/api/examples	GET	List all built-in examples. Returns: [{"name", "code"}]
/api/version	GET	Returns the GALA version. Returns: {"version": "0.61.1"}
/	GET	Serves the playground UI

Limits

• Code size: 50 KB max
• Execution timeout: 30 seconds
• Single file: each run is a single main.gala with package main

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Docker Details

The Dockerfile uses a multi-stage build:

Stage	Base Image	Purpose
builder	golang:1.25.5-alpine	Downloads GALA and compiles main.gala via gala build
Runtime	golang:1.25.5-alpine	Runs both the server and gala run

The runtime image includes Go because gala run invokes go build internally. The GALA stdlib and Go module cache are pre-warmed during the Docker build so the first user request is fast.

Configuration

Environment Variable	Default	Description
BIND_ALL	1 (in Docker)	Bind to 0.0.0.0 instead of 127.0.0.1
PORT	3000	Server port

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License

Apache License 2.0. See LICENSE for details.