- Show 2 lines of context before and after errors (dimmed)
- Fix guessing_game.lux to be non-interactive for testing
- Use binary search simulation to demonstrate game logic
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 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 full support for user-defined generic types and functions:
- Add type_params field to TypeChecker to track type parameters in scope
- Update resolve_type() to resolve type parameters to their bound variables
- Update function_type() to bind type parameters and return polymorphic TypeScheme
- Update type declaration handling for generic ADTs (e.g., Pair<A, B>)
Generic functions and types now work:
fn identity<T>(x: T): T = x
type Pair<A, B> = | MkPair(A, B)
fn first<A, B>(p: Pair<A, B>): A = ...
Add examples/generics.lux demonstrating:
- Generic identity function
- Generic Pair type with first/second accessors
- Generic mapOption function
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>
