# Baseline

> Baseline is a strongly typed, effect-tracked functional programming language. Extension: `.bl`, compiler: `blc`. "The type is the spec" -- refinements encode correctness. "Effects are data" -- side effects are explicit capabilities. Experimental, not production-ready.

Important -- LLMs commonly get these wrong:
- `!` means EFFECTS, not negation. Use `not` for boolean negation.
- NO method syntax. Write `String.to_upper(name)`, never `name.to_upper()`.
- NO `+` for strings. Write `"Hello, ${name}!"`, never `"Hello, " + name`.
- NO semicolons. Statements are separated by newlines.
- NO `return` keyword. The last expression is the return value.
- Bindings are immutable by default. Use `let mut` for mutable locals.

## Docs

- [Quick syntax reference and common patterns (small context)](https://baseline-lang.com/llms-small.txt): Rosetta Stone, syntax rules, common mistakes, stdlib summary, patterns. Best for quick code generation.
- [Full language and API reference (large context)](https://baseline-lang.com/llms-full.txt): Everything in the small reference plus complete stdlib API with signatures and examples.

## Getting Started

- [Guide](https://baseline-lang.com/guide): Quick start tutorial
- [Learn](https://baseline-lang.com/learn): Interactive language tour

## Reference

- [API Reference](https://baseline-lang.com/api): Standard library documentation
- [Design](https://baseline-lang.com/design): Language design philosophy

## Optional

- [Changelog](https://baseline-lang.com/changelog): Version history
- [GitHub](https://github.com/baseline-lang/baseline): Source code and issues