- Add String.fromChar function to convert Char to String
- Create four stress test projects demonstrating Lux features:
- json-parser: recursive descent parsing with Char handling
- markdown-converter: string manipulation and ADTs
- todo-app: list operations and pattern matching
- mini-interpreter: AST evaluation and environments
- Add comprehensive testing documentation (docs/testing.md)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add readLine and readInt operations to the Console effect for interactive
input. Create a number guessing game project demonstrating ADTs, pattern
matching, effects, and game state management.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add Http effect for making HTTP requests:
- Http.get(url) - GET request
- Http.post(url, body) - POST with string body
- Http.postJson(url, json) - POST with JSON body
- Http.put(url, body) - PUT request
- Http.delete(url) - DELETE request
Returns Result<HttpResponse, String> where HttpResponse contains
status code, body, and headers.
Includes reqwest dependency with blocking client, OpenSSL support
in flake.nix, and example at examples/http.lux demonstrating
API requests with JSON parsing.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add comprehensive JSON support via the Json module:
- Parse JSON strings with Json.parse() returning Result<Json, String>
- Stringify with Json.stringify() and Json.prettyPrint()
- Extract values with Json.get(), getIndex(), asString(), asInt(), etc.
- Build JSON with constructors: Json.null(), bool(), int(), string(), array(), object()
- Query with Json.isNull() and Json.keys()
Includes example at examples/json.lux demonstrating building, parsing,
and extracting JSON data with file I/O integration.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Adds two essential effects that enable Lux to interact with the system:
File effect:
- read(path) - Read file contents as string
- write(path, content) - Write string to file
- append(path, content) - Append to file
- exists(path) - Check if file/directory exists
- delete(path) - Delete a file
- readDir(path) - List directory contents
- isDir(path) - Check if path is directory
- mkdir(path) - Create directory (including parents)
Process effect:
- exec(cmd) - Run shell command, return stdout
- execStatus(cmd) - Run command, return exit code
- env(name) - Get environment variable (returns Option)
- args() - Get command line arguments
- exit(code) - Exit program with code
- cwd() - Get current working directory
- setCwd(path) - Change working directory
Also fixes formatter bug with empty handler blocks in `run ... with {}`.
These effects make Lux capable of writing real CLI tools and scripts.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Add Math module: abs, min, max, sqrt, pow, floor, ceil, round
- Add List functions: isEmpty, find, any, all, take, drop
- Add String functions: startsWith, endsWith, toUpper, toLower, substring
- Add 12 tests for new standard library functions
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add Schema module with functions for creating and migrating versioned
values. This provides the runtime foundation for schema evolution.
Schema module functions:
- Schema.versioned(typeName, version, value) - create versioned value
- Schema.migrate(value, targetVersion) - migrate to new version
- Schema.getVersion(value) - get version number
Changes:
- Add Versioned, Migrate, GetVersion builtins to interpreter
- Add Schema module to global environment
- Add Schema module type to type environment
- Add 4 tests for schema operations
- Add examples/versioning.lux demonstrating usage
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add support for the `resume(value)` expression in effect handler
bodies. When resume is called, the value becomes the return value
of the effect operation, allowing handlers to provide values back
to the calling code.
Implementation:
- Add Resume(Value) variant to EvalResult
- Add in_handler_depth tracking to Interpreter
- Update Expr::Resume evaluation to return Resume when in handler
- Handle Resume results in handle_effect to use as return value
- Add 2 tests for resumable handlers
Example usage:
```lux
handler prettyLogger: Logger {
fn log(level, msg) = {
Console.print("[" + level + "] " + msg)
resume(()) // Return Unit to the call site
}
}
```
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add Random and Time effects for random number generation and
time-based operations. These effects can be used in any
effectful code block.
Random effect operations:
- Random.int(min, max) - random integer in range [min, max]
- Random.float() - random float in range [0.0, 1.0)
- Random.bool() - random boolean
Time effect operations:
- Time.now() - current Unix timestamp in milliseconds
- Time.sleep(ms) - sleep for specified milliseconds
Changes:
- Add rand crate dependency
- Add Random and Time effect definitions to types.rs
- Add effects to built-in effects list in typechecker
- Implement effect handlers in interpreter
- Add 4 new tests for Random and Time effects
- Add examples/random.lux demonstrating usage
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add runtime support for the State, Reader, and Fail effects that
were already defined in the type system. These effects can now be
used in effectful code blocks.
Changes:
- Add builtin_state and builtin_reader fields to Interpreter
- Implement State.get and State.put in handle_builtin_effect
- Implement Reader.ask in handle_builtin_effect
- Add Reader effect definition to types.rs
- Add Reader to built-in effects list in typechecker
- Add set_state/get_state/set_reader/get_reader methods
- Add 6 new tests for built-in effects
- Add examples/builtin_effects.lux demonstrating usage
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Add string concatenation support to + operator in typechecker
- Register ADT constructors in both type environment and interpreter
- Bind handlers as values so they can be referenced in run...with
- Fix effect checking to use subset instead of exact match
- Add built-in effects (Console, Fail, State) to run block contexts
- Suppress dead code warnings in diagnostics, modules, parser
Update all example programs with:
- Expected output documented in comments
- Proper run...with statements to execute code
Add new example programs:
- behavioral.lux: pure, idempotent, deterministic, commutative functions
- pipelines.lux: pipe operator demonstrations
- statemachine.lux: ADT-based state machines
- tailcall.lux: tail call optimization examples
- traits.lux: type classes and pattern matching
Add documentation:
- docs/IMPLEMENTATION_PLAN.md: feature roadmap and status
- docs/PERFORMANCE_AND_TRADEOFFS.md: performance analysis
Add benchmarks for performance testing.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add support for type classes (traits) with full parsing, type checking, and
validation. The implementation includes:
- Trait declarations: trait Show { fn show(x: T): String }
- Trait implementations: impl Show for Int { fn show(x: Int) = ... }
- Super traits: trait Ord: Eq { ... }
- Trait constraints in where clauses: where T: Show + Eq
- Type parameters on traits: trait Functor<F> { ... }
- Default method implementations
- Validation of required method implementations
This provides a foundation for ad-hoc polymorphism and enables
more expressive type-safe abstractions.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add trampoline-based tail call optimization to prevent stack overflow
on deeply recursive tail-recursive functions. The implementation:
- Extends EvalResult with TailCall variant for deferred evaluation
- Adds trampoline loop in eval_expr() to handle tail calls iteratively
- Propagates tail position through If, Let, Match, and Block expressions
- Updates all builtin callbacks to handle tail calls via eval_call_to_value
- Includes tests for deep recursion (10000+ calls) and accumulator patterns
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Implement beautiful, informative error messages inspired by Elm:
- Rich diagnostic rendering with source code snippets
- Colored output with proper underlines showing error locations
- Categorized error titles (Type Mismatch, Unknown Name, etc.)
- Contextual hints and suggestions for common errors
- Support for type errors, runtime errors, and parse errors
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
