# EPL — English Programming Language

> EPL is a programming language with English syntax (v10.2.0). Write code in plain English — apps, web servers, APIs, desktop GUIs, and mobile apps. Install: `pip install eplang`. Run: `epl run file.epl`. By default `epl run` executes on a bytecode VM (real closures + full control-flow parity with the reference interpreter); `--interpret` selects the tree-walking interpreter. EPL also transpiles to Python/JS/Node/Kotlin/MicroPython, compiles native binaries (`epl build`, with type inference for untyped functions), and exports native mobile/desktop projects (`epl android`/`ios`/`desktop`, with `--webview` to ship the real web app unchanged).

## Documentation

- [Official Website](https://eplang.me/): Homepage with live playground and install guide
- [What is EPL?](https://eplang.me/what-is-epl.html): Overview, FAQ, and how EPL compares to Python
- [Syntax Reference](https://github.com/abneeshsingh21/EPL/blob/main/GRAMMAR.md): Formal grammar specification
- [Examples](https://github.com/abneeshsingh21/EPL/tree/main/examples): 50+ working programs (`examples/apps/` has full apps)
- [README](https://github.com/abneeshsingh21/EPL/blob/main/README.md): Getting started guide
- [Changelog](https://github.com/abneeshsingh21/EPL/blob/main/CHANGELOG.md): Version history
- [Full Reference for LLMs](https://eplang.me/llms-full.txt): Complete syntax + examples for AI consumption

## Key Syntax Rules

- Variables: `Create name = "Ada"`, `Set count to 5`, or bare `count = 5`
- Output: `Say "Hi"`, `Display "Hi"`, `Print "Hi"`, `Show "Hi"` (all equivalent)
- Input: `Ask "Name?" store in name`
- Interpolation: `Say "Hello $name"` and `Say "Sum ${1 + 2}"`
- Functions: `Function greet takes name ... End`; call `greet("Ada")`
- Conditionals: `If x > 5 Then ... Otherwise ... End` — use `Otherwise`, NOT `Else`
- Loops: `For i from 1 to 10 ... End`, `For each x in list ... End`, `While c ... End`, `Repeat 5 times ... End`
- Match: `Match x` / `When 1 or 2` (each alternative tested) / `Default` (or `Otherwise`) / `End`
- Classes: `Class Dog ... End` with bare fields (`name = "Rex"`); instantiate `new Dog()`; methods use fields directly
- Web: `Create WebApp called app` → `Route "/" shows ... End` (HTML) / `Route "/api" responds with ... End` (JSON) → `Start app on port 8080`
- Maps: `Create user = Map with name = "Ada" and role = "admin"` — access `user.name`
- Assign into collections: `Set list[i] to value`, `Set obj.prop to value`
- Errors: `Try ... Catch error ... End`
- Comments: `Note: this is a comment` — NOT `//` or `#`
- Every block (If/Function/Class/While/For/Match/Route/Try) ends with `End`

## Common Builtins (verified names)

- Strings: `length`, `upper`, `lower`, `trim`, `replace`, `split`, `join`, `substring`, `contains`, `index_of`, `reverse`, `starts_with`, `ends_with`
- Convert: `to_text`, `to_integer`, `to_number`, `to_boolean`
- Math: `absolute` (or `abs`), `round`, `floor`, `ceil`, `power`, `sqrt`, `min`, `max`, `random(a, b)`, `sum`
- Collections/maps: `keys`, `values`, `has_key`, `first`, `last`, `Add x to list`, `Sort list` (statement)
- Type: `type_of` → "integer"/"text"/"boolean"/"list"/"map"
- Auth: `auth_hash_password`, `auth_verify_password`, `auth_generate_token`
- Database: `db_open`, `db_execute`, `db_query`, `db_query_one`, `db_count`, `db_close` (+ `*_params` variants)
- Env/time: `env_get` (a `.env` beside the program is auto-loaded), `now`, `today`, `Wait N seconds`, `Exit`

## CLI

- `epl run file.epl` (bytecode VM) · `epl run --interpret file.epl` · `epl vm file.epl`
- `epl build file.epl [-o out] [--opt=N]` — native binary (infers types for untyped functions)
- `epl wasm file.epl` — WebAssembly
- `epl python|js|node|kotlin|micropython file.epl [-o out]` — transpile
- `epl android|ios|desktop|web file.epl [--webview] [--url URL]` — native/app export
- `epl new <name> --template web|api|auth|chatbot|cli|lib|frontend|android|ios|fullstack`
- `epl serve file.epl [--reload] [--port N]` · `epl repl` · `epl watch` · `epl doctor` · `epl check`
- `epl test` · `epl fmt` · `epl lint` · `epl docs`
- `epl use|install|uninstall|packages|search|update` (packages) · `epl deploy <target>`
- `epl gen "<desc>"` · `epl ai "<prompt>"` · `epl explain file.epl` · `epl copilot` · `epl playground` · `epl lsp`

## Optional

- [MCP Server](https://github.com/abneeshsingh21/EPL): `python -m epl.mcp_server` — tools `epl_syntax_reference`, `epl_validate`, `epl_run`, `epl_transpile`, `epl_examples`, `epl_error_lookup` for AI tools (Claude Desktop, Cursor, VS Code)
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