Add wrenNewStringFromRange function to wren_value.c that decodes UTF-8 code points from source string and re-encodes them into result, enabling correct range subscripts on multi-byte characters. Rename wrenUtf8NumBytes to wrenUtf8EncodeNumBytes and make wrenUtf8Encode return written byte count for use in range construction. Add wrenUtf8DecodeNumBytes utility to skip continuation bytes when iterating by byte index. Remove all skip directives from test files and add UTF-8 specific test cases verifying correct slicing across code point boundaries.
The compiler no longer auto-generates a default `new()` constructor for classes. All classes must now explicitly define `construct new() {}` to be instantiable. This change removes the `createDefaultConstructor` function from the compiler, eliminates the `return_this` primitive used by Object's default initializer, and adds explicit constructors to all test and example classes. Core metaclasses (Bool, Class, Null, Num, Object, Range, Sequence) now correctly reject `new()` calls with runtime errors.
Add finalizer invocation for foreign objects during garbage collection by calling wrenFinalizeForeign in wrenFreeObj. Expose wrenCollectGarbage as a public API function and update internal calls accordingly. Ensure the "<finalize>" symbol is always registered in the symbol table even when no finalizer is provided. Add test fixtures for Resource class with finalizer and Api.gc/Api.finalized methods to verify finalization behavior across multiple GC cycles.
The ignoreNewlines() call following list instantiation via callMethod(compiler, 0, "new()", 5) was redundant because the subsequent do-while loop for compiling list elements already handles newline skipping internally. Removing this duplicate call eliminates unnecessary parser state manipulation without affecting list compilation behavior.
- Convert list() and map() compiler functions from if/do-while to do-while loops
- Remove redundant empty literal handling by breaking on right bracket/brace
- Add new test files for duplicate comma, duplicate trailing comma, and empty list/map with comma
- Expand newlines test to cover trailing comma and empty list/map cases
- Simplify trailing_comma tests by removing inline syntax error checks
- Update Test.fail() to handle variable arguments without kwargs
Add support for trailing commas in list literals by checking for TOKEN_RIGHT_BRACKET
after parsing the last element in the list() function. When a trailing comma is
followed by the closing bracket, the loop breaks immediately instead of attempting
to parse another element.
Include a test case verifying that lists with trailing commas parse correctly and
elements are accessible by index.
Add a check in the map parsing function to break when encountering a closing brace after a comma, enabling trailing commas in map literals. Include a test case verifying that maps with trailing commas parse and execute correctly.
Remove the run() method from fibers and introduce transfer() for non-stack-based fiber switching, along with suspend() to pause the interpreter and return control to the host application. Update Timer.sleep() to use runNextScheduled_() instead of Fiber.yield(), and add Timer.schedule() for creating independently scheduled fibers. Refactor the core fiber runtime to support transfer semantics, including proper error handling for aborted fibers and self-transfer edge cases. Fix a missing quote in test.py's runtime error validation string.
- Add Alexander Roper to AUTHORS file with newline fix for Starbeamrainbowlabs entry
- Replace placeholder embedding API docs with full guide covering static/dynamic linking and source inclusion
- Update codebase line count from 5,000 to 7,000 lines in README and index
- Fix relative documentation links to absolute URLs in README
- Add CSS styling for preprocessor directive syntax highlighting
- Update Xcode project file references and CopyFiles build phase UUID
- Adjust delta_blue benchmark expected value from 7032700 to 14065400
- Improve markdown header detection regex in generate_docs.py to avoid matching #include
- Refactor metrics.py to exclude curly brace lines from code line counting
- Add TEST_HEADERS dependency to test object compilation in wren.mk
- Remove NULL parameter from runFile call in main.c
- Refactor vm.c to support WrenBindForeignClassFn callback and rename externalBindForeign to bindMethodFn
- Update vm.h to remove bindForeign parameter documentation and adjust runFile signature
Replace the separate `string` ByteBuffer and `number` double fields in the Parser struct with a single `value` field of type Value. This unifies literal storage, simplifies the parser's state, and eliminates the need for separate buffers and conversion logic for different literal types.
The change modifies `makeNumber` to store parsed numbers as `NUM_VAL` directly into `parser->value`, and adds a guard in `addConstant` to return -1 early if the parser has encountered an error.
Rename the constructor initializer signature prefix from "this " to "init " in
wren_common.h's MAX_METHOD_SIGNATURE calculation, wren_compiler.c's
signatureToString and createDefaultConstructor functions, and wren_core.c's
default Object constructor primitive registration. This changes the syntactic
keyword used to define initializer methods in the Wren language.
- Changed error message in `constructorSignature` from "Expect constructor name after 'this'." to "Expect constructor name after 'construct'."
- Updated comment in `createDefaultConstructor` from "It just invokes 'this new()' on the instance" to "It just invokes 'construct new()' on the instance"
Implement the initial infrastructure for foreign classes in the Wren VM, including new opcodes (FOREIGN_CONSTRUCT, FOREIGN_CLASS), a WrenBindForeignClassFn callback type in the public API, and updated CLI vm.c to store and forward foreign binding callbacks via setForeignCallbacks(). The compiler now tracks whether a class is foreign via a new isForeign flag in ClassCompiler, emits CODE_FOREIGN_CONSTRUCT instead of CODE_CONSTRUCT for foreign class constructors, and errors on field definitions inside foreign classes. The debug dump and opcode header gain entries for the new opcodes, and wrenBindSuperclass handles the -1 numFields sentinel for foreign classes to prevent field inheritance from superclasses.
The timerGetSource function allocates a buffer and copies the source string using strncpy, which does not guarantee null termination when the source length equals the buffer size. This change explicitly sets the final character to '\0' to prevent potential buffer over-reads or undefined behavior when the returned string is used by callers.
Add type and range checks to Timer.sleep() in both C source and Wren
implementation, aborting with descriptive errors for non-numeric or
negative arguments. Introduce six new test files covering sleep with
fibers, float durations, main fiber, zero milliseconds, negative
values, and non-numeric input. Fix stack trace parsing in test runner
to skip builtin library frames by iterating through error lines until
a main-line match is found.
Add a vertical slice of real libuv integration by introducing a "timer" CLI module with a Timer class and static sleep() method. This required significant infrastructure changes: setting up libuv event loop in the CLI, creating a new src/module directory for CLI modules, updating all build scripts (Makefile, wren.mk, Xcode project) to handle the new module compilation, and reorganizing CLI code by moving REPL logic from main.c to vm.c. The generate_builtins.py script was also updated to support copying Wren sources into the module directory.
Extend the wrenCall variadic argument handling to accept a new 'v' type specifier,
which allows callers to pass a previously acquired WrenValue* directly without
implicitly releasing it. This enables reusing existing Wren values across multiple
calls without unnecessary string or number conversions.
The implementation reads a WrenValue* from the variadic arguments and extracts
its internal Value for the call. Additionally, fix the parameter counting logic
in makeCallStub to correctly count underscore parameters only within the
parenthesized signature portion, preventing off-by-one errors for methods with
trailing parentheses in their signature strings.
Introduce WrenValue type and wrenGetArgumentValue/wrenReleaseValue functions to allow C code to hold GC-safe references to Wren objects across foreign calls. Implement doubly-linked list management in VM struct, mark value handles during garbage collection, and add assertion in wrenFreeVM to detect unreleased values. Update test infrastructure with new get_value test case and rename existing test binding functions to camelCase convention.
Refactor wrenFindVariable to accept an explicit ObjModule* parameter instead of
implicitly using the main module. Promote the internal getCoreModule helper to
a public wrenGetCoreModule function declared in wren_vm.h. Update all call sites
in wren_core.c and wren_meta.c to pass the core module when looking up core
variables, and replace inline getCoreModule calls in wren_vm.c with the new
public function. Remove the NULL-module fallback documentation from
wrenDeclareVariable and wrenDefineVariable.
The addEntry function was incorrectly skipping tombstone entries when inserting new keys, causing the map to fill up with tombstones and eventually deadlock on insert. The fix removes the tombstone check that prevented overwriting tombstone slots with new entries, allowing proper reuse of removed entries.
A regression test (test/core/map/churn.wren) was added to verify that inserting and removing entries in a loop correctly maintains the map count without deadlocking.
Add TOKEN_CONSTRUCT as a new reserved word in the Wren compiler lexer and parser, and update the grammar rule table so that 'construct' triggers a constructor signature instead of 'this'. Modify all built-in class definitions in core.wren, wren_core.c, benchmark files, and test fixtures to use 'construct new(...)' and 'construct named(...)' syntax. Update documentation in classes.markdown and syntax.markdown to reflect the new keyword, and remove the deprecated test files for 'new' and infix class expressions.
- Switch Travis CI from sudo-based apt-get to addons.apt.packages for gcc-multilib
- Enable container-based builds with `sudo: false`
- Update README.md call-to-action links to point to getting-started and browser playground
- Replace `printList_` with `printAll` in IO class and remove redundant `IO.` prefixes
- Add IO.read() method documentation and update IO.print docs for up to 16 arguments
- Reorganize community page with Libraries, Language bindings, and Tools sections
- Add wrenjs JavaScript binding and Sublime Text syntax highlighting
- Fix typo "no where" to "nowhere" in fibers documentation
- Add indentation to preprocessor defines in wren_common.h for consistency
- Remove unreachable `return 0` after UNREACHABLE() in wren_compiler.c
- Fix Windows color output by wrapping text in str() in test script
Replace three duplicated switch-on-type patterns (in wrenDebugPrintStackTrace, wrenAppendCallFrame, and runInterpreter) with a single static inline wrenGetFrameFunction that handles OBJ_FN and OBJ_CLOSURE cases with an UNREACHABLE default.
Rename private `printList_` to public `printAll` across all overloaded `IO.print` methods in both Wren source and embedded C string. Update `IO.read` to require explicit `()` call syntax in test and documentation. Revise IO documentation to clarify `print`, `printAll`, `write`, and `read` semantics with updated examples.
Replace all uses of the `new` reserved word with explicit `this new()` constructor definitions and `ClassName.new()` instantiation calls in builtin/core.wren. Update all documentation files (classes.markdown, fiber.markdown, fn.markdown, sequence.markdown, error-handling.markdown, expressions.markdown, fibers.markdown, functions.markdown) to reflect the new constructor syntax, removing `new` keyword examples and replacing them with `ClassName.new()` patterns and `this new()` definitions.
Add support for parsing scientific notation (e.g., 2.55e2, -2.55e-2) in the
readNumber function of wren_compiler.c. The implementation handles optional
negative exponents, validates that exponent digits follow 'e'/'E', and emits
a lex error for unterminated scientific notation. Also adds comprehensive
test cases covering valid scientific literals, missing exponents, floating
exponents, missing fractional parts, and multiple exponents.
Replace the statically-sized CallFrame array in ObjFiber with a dynamically
allocated array that starts at INITIAL_CALL_FRAMES (4) and doubles when
capacity is exceeded. This reduces memory for new fibers and improves
fiber creation benchmark performance by ~45%.
Extract the common pattern of returning the receiver argument into a single
DEF_PRIMITIVE(return_this) function, and refactor fiber_instantiate,
fn_instantiate, and the default Object constructor to use it instead of
inline RETURN_VAL(args[0]) calls. Also fix trailing whitespace on isEmpty
and class_toString lines in the core library source string.
Extract class name retrieval from object_toString into a new class_toString primitive, registered on the Class metaclass. This removes the IS_CLASS branch from object_toString, which now only handles instances and falls back to "<object>". The change ensures Class objects return their own name directly via toString rather than relying on the generic object handler.
Eliminate the performance penalty of an if-test inside the call instruction loop by using explicit goto to share the common tail-end call-handling code between normal and superclass calls. This improves interpreter throughput across multiple benchmarks, with gains of up to 23% on the 'for' benchmark and 14% on 'fib'.
When a block is passed as an argument to a method call, the generated
function's debug name now includes the method's signature followed by
" block argument" instead of the generic "(fn)" placeholder. This
improves debugging by showing which method the block belongs to.
Add test cases for single-byte incomplete two-octet and three-octet UTF-8 sequences
in code_point_at_incomplete.wren, and remove the resolved TODO comment about testing
truncated UTF-8 buffer reads in wrenUtf8Decode.
Bob Nystrom
Lukas Werling
minirop
Rohan Singh