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Gleam Cheatsheet

Quick reference guide for Gleam — Web backends, CLI tools, BEAM/JS targets

CategoryLanguages
ParadigmFunctional
TypingStatic
Created2016 by Louis Pilfold
File Extension.gleam
Sections10 topics

Types & Type Aliases in Gleam provides essential functionality for building robust applications. Understanding these concepts helps you write cleaner, more maintainable code and follow Gleam best practices.

Key Concepts

  • Understanding types & type aliases is essential for effective Gleam development. Master the fundamentals before moving to advanced patterns.
  • Best practices include writing clean, readable code with proper naming conventions and consistent formatting.
  • Refer to the official Gleam documentation for the latest syntax and API changes.

Pattern matching provides concise syntax for branching logic based on data structure. It replaces verbose if-else chains with declarative, exhaustive matching expressions.

Key Concepts

  • Understanding pattern matching is essential for effective Gleam development. Master the fundamentals before moving to advanced patterns.
  • Best practices include writing clean, readable code with proper naming conventions and consistent formatting.
  • Refer to the official Gleam documentation for the latest syntax and API changes.

Pipes in Gleam provides essential functionality for building robust applications. Understanding these concepts helps you write cleaner, more maintainable code and follow Gleam best practices.

Key Concepts

  • Understanding pipes is essential for effective Gleam development. Master the fundamentals before moving to advanced patterns.
  • Best practices include writing clean, readable code with proper naming conventions and consistent formatting.
  • Refer to the official Gleam documentation for the latest syntax and API changes.

About Gleam

Gleam is a functional programming language created by Louis Pilfold in 2016. It is primarily used for web backends, cli tools, beam/js targets. Gleam uses static typing, which catches type errors at compile time, improving code reliability and IDE support.

Why Use This Gleam Cheatsheet?

  • Quick Reference — Find syntax and patterns instantly without searching through documentation.
  • Organized by Topic10 sections covering all major Gleam concepts, from basics to advanced.
  • Always Updated — Covers the latest Gleam features and best practices for 2026.
  • Searchable — Use the search bar to jump to exactly the concept you need.

Getting Started with Gleam

Whether you're new to Gleam or an experienced developer looking for a quick reference, this cheatsheet covers the essential concepts you need. Start with the fundamentals like types & type aliases and pattern matching, then progress to more advanced topics like external functions and otp interop.

Gleam has been widely adopted since its creation in 2016, with a strong community and ecosystem. Files typically use the .gleam extension. For the most comprehensive and up-to-date information, always refer to the official Gleam documentation alongside this cheatsheet.

Methodology & Sources for Gleam

How we compile Gleam cheatsheet content: Each entry is sourced from official Gleam documentation, language specifications (where applicable), and community-validated patterns from Stack Overflow Developer Survey data. Examples are tested against current language/framework versions and updated quarterly.

  1. Primary source: official Gleam documentation and language specification.
  2. Examples: validated against current stable release (latest LTS where applicable).
  3. Use cases: derived from Stack Overflow Developer Survey patterns and GitHub trending repositories.
  4. Common pitfalls: cataloged from real-world bug reports, GitHub issues, and Stack Overflow Q&A.

Authoritative sources:

Disclaimer: Cheatsheet content reflects standard usage patterns. Always verify with official documentation for your specific version. Code examples may need adaptation for your environment, dependencies, or framework version.

Reviewed by Brazora Monk · Last updated 2026

Standards, Specs & Security References for Gleam

For production code in Gleam, always verify against canonical specifications and security guidance — not just tutorials. Common runtime / language-version compatibility issues are addressed by:

📜 Canonical Specs

Always cite the spec, not paraphrases:

🛡️ Security Standards

Avoid common vulnerabilities:

📦 Package Registries

Verify dependencies + audit:

🏗️ Build & Deploy

Modern toolchain references:

ReDoS warning: Regex patterns with nested quantifiers can cause catastrophic backtracking. Test patterns with regex101.com and check OWASP ReDoS guidance before deploying user-input regex.

Frequently Asked Questions

What is Gleam used for?

Gleam is primarily used for web backends, cli tools, beam/js targets. It was created by Louis Pilfold in 2016. It follows the functional paradigm.

Is Gleam hard to learn?

Gleam has a moderate learning curve. Start with the basics covered in sections like Types & Type Aliases and Pattern Matching, then gradually work through more advanced topics. This cheatsheet helps by providing quick references for each concept.

How do I use this cheatsheet?

Use the search bar to find specific topics, click section headers to expand/collapse content, and use the table of contents for quick navigation. You can also expand or collapse all sections at once.