Add a public `arity` getter to the Fn class that returns the number of required arguments for a function. Internally rename the `numParams` field to `arity` across the codebase for consistency, update the C API parameter name from `numParams` to `arity` in `wrenDefineMethod` and `wrenDefineStaticMethod`, and adjust the error message in `callFunction` to use the new field name. Also update documentation to clarify that extra arguments are ignored rather than causing an error, and add a new test file `test/function/arity.wren` verifying arity values from 0 to 4.
Add Visual Studio 2013 solution and project files under project/msvc2013/ directory, enabling native Windows builds without MinGW. Include Marco Lizza in AUTHORS for the contribution. Fix C89 compatibility issues for MSVC: disable computed goto via _MSC_VER check, define inline as _inline for non-C++ mode, change flexible array members from empty brackets to [0] syntax, and fix char to int type for readHexDigit return value. Refactor single-line if/while/for bodies in wren_compiler.c to use braces to satisfy MSVC stricter parsing.
Add String as a subclass of Sequence in core.wren and implement the iterator protocol for strings in wren_core.c. The string_iterate native advances through UTF-8 code point boundaries, while string_iteratorValue extracts the full code point at a given byte index. Includes comprehensive test coverage for iteration, edge cases (empty strings, mid-sequence positions), and error handling for invalid iterator types and out-of-bounds indices. Also updates documentation for String, List, and Sequence classes with iterator protocol details and usage examples.
Add runtime type validation to wrenGetArgumentBool, wrenGetArgumentDouble, and
wrenGetArgumentString in src/wren_vm.c, replacing TODO comments with actual
checks that return safe defaults (false, 0.0, NULL) on type mismatch.
Remove the unused wrenReturnNull function entirely from the VM implementation.
Update include/wren.h documentation for argument accessor functions to clarify
indexing semantics (including receiver at index 0) and document the new
type-checking behavior.
The diff reorders the `children` array of the `src` group in the Xcode project file,
moving `.c` files after their corresponding `.h` headers to match a consistent
header-before-source convention.
The modulo operator was incorrectly assigned PREC_TERM precedence, causing it to
bind less tightly than multiplication and division. This change promotes it to
PREC_FACTOR, matching the standard mathematical precedence where `%` has the
same binding strength as `*` and `/`.
A test case `IO.print(13 + 1 % 7)` is added to verify the fix, expecting `14`
(equivalent to `13 + (1 % 7)`) rather than the incorrect `(13 + 1) % 7 = 0`.
Rename all instances of "pinned" objects to "temporary roots" in wren_vm.c, wren_vm.h, and wren_common.h to better describe their stack-based lifecycle. Update the WREN_MAX_PINNED constant to WREN_MAX_TEMP_ROOTS, rename the vm->pinned array to vm->tempRoots, and rename vm->numPinned to vm->numTempRoots. Adjust all related comments and assertions to reflect the new terminology, including the GC stress test comment in wren_common.h.
Refactor parameter list parsing to support bracket-delimited parameters for
subscript operators. Extract finishParameterList from parameterList to handle
the common closing logic, and add TOKEN_RIGHT_BRACKET case for error messages.
Add comprehensive test suite for subscript getters and setters with 1-3
parameters in test/method/subscript_operators.wren.
- Insert "Getting acquainted" section in contributing guide with mailing list invitation
- Add proposal link for significant changes discussion before coding
- Promote mailing list as primary contact method in getting-started page
- Add link references for list, twitter, issue, and repo in getting-started
- Relocate wren.xcodeproj into project/xcode/ subdirectory
- Remove build_xcode/ from .gitignore as it is no longer at root level
- Update all internal PBXBuildFile references to use new file paths
The AS_OBJ macro on NaN-tagged architectures was performing a direct cast from
uint64_t to Obj* which triggers a pointer-to-integer cast warning on 32-bit
MinGW where sizeof(Obj*) is 4 bytes. Adding an intermediate cast to uintptr_t
ensures the value is properly truncated before conversion to the pointer type.
Also replaces IS_SINGLETON macro usage with direct NULL_VAL/UNDEFINED_VAL
comparisons and removes the now-unused IS_SINGLETON definition.
The CalculatedRange struct is removed from the header and calculateRange now returns the start index directly while using pointer parameters for length and step, simplifying the API and reducing struct overhead.
Extract range validation logic into a reusable `calculateRange` function that handles inclusive/exclusive bounds, negative indices, and direction stepping. Add `CalculatedRange` struct to `wren_core.h` and implement string subscript tests covering forward, backward, negative, and half-negative ranges along with comprehensive error cases for out-of-bounds and non-integer range endpoints.
Replace signed `int` with unsigned `uint8_t` for field indices in LOAD_FIELD_THIS, STORE_FIELD_THIS, LOAD_FIELD, and STORE_FIELD opcodes, and with `uint16_t` for jump offsets in JUMP, LOOP, and JUMP_IF opcodes. This eliminates sign-extension overhead and enables better code generation, yielding 1-7% performance gains across binary_trees, delta_blue, fib, for, and method_call benchmarks.
The consume() function previously returned a pointer to the consumed token,
and consumeLine() returned a boolean indicating success. Both return values
were never used by any callers. This change converts both functions to void,
eliminating dead code and simplifying the interface.
Add a new public API function `wrenGetArgumentBool` to the Wren VM that
allows foreign method implementations to retrieve boolean arguments from
the foreign call slot. The implementation includes assertions for null
slot, non-negative index, and bounds checking against the number of
arguments, and uses the existing AS_BOOL macro to extract the boolean
value from the slot.
Add a new public API function `wrenReturnBool` to the Wren C API, enabling
foreign method implementations to return boolean values. The implementation
stores the boolean as a Wren BOOL_VAL in the foreign call slot and clears
the slot pointer, following the same pattern as existing `wrenReturnString`.
Also add the missing `prep` target to the .PHONY list in the Makefile and
include `<stdbool.h>` in the public header to support the `bool` type used
in the new function signature.
The `is` operator was placed at `PREC_IS` which had lower precedence than `PREC_EQUALITY`, causing expressions like `true == 10 is Num` to parse incorrectly. Moved `PREC_IS` above `PREC_EQUALITY` in the precedence enum to give `is` higher binding power than `==` and `!=`. Added precedence tests in new `test/precedence.wren` file and removed TODO comments about precedence from `test/is/is.wren`.
The prep target was missing from the .PHONY declaration, causing Make to skip
its execution when a file named 'prep' existed in the working directory. This
change ensures prep is always treated as a phony target and executed regardless
of file system state.
Add a new public API function `wrenReturnBool` to the Wren C API, allowing
foreign method implementations to return boolean values. The function
includes the necessary `stdbool.h` include in the public header and
implements the return logic by storing a BOOL_VAL in the foreign call slot,
following the same pattern as existing return functions like
`wrenReturnNull` and `wrenReturnString`.
Remove the Linux-specific `_GNU_SOURCE` macro and `getline()` usage in the REPL loop, replacing them with a fixed-size `fgets()` buffer of 1024 bytes. Also switch `snprintf` to `sprintf` in `wren_vm.c` for the field limit error message, eliminating the need for `_GNU_SOURCE` entirely.
The benchmark HTML output previously displayed abstract "score" values and scaled bars by the highest score. This change replaces scores with the actual minimum execution time in seconds (e.g., "0.15s") and scales bar widths proportionally to the highest time, making the charts directly interpretable as performance comparisons. The `run_bench` script now computes `time` from `min(result["times"])` instead of `get_score()`, and the static performance documentation is updated to reflect the new time-based values.
Update the Method Call and DeltaBlue benchmark tables with new Wren performance results (6748 and 7564 respectively), adjusting all other language scores and corresponding chart-bar width percentages to reflect the latest measurements.
Replace the C99 designated initializer syntax for `WrenConfiguration config` with explicit field assignments to avoid potential compiler compatibility issues. The change preserves the same configuration values: `reallocateFn` set to NULL, `heapGrowthPercent` and `minHeapSize` set to 0, and `initialHeapSize` set to 100 MB.
Add native `!` methods to Null, Object, Num, String, and List classes so that `!` works reliably on any value. Null returns `true`, all other types return `false` since they are considered truthy. Update documentation to describe the operator as returning the logical complement and add comprehensive tests for each type. Also fix the `all` method test to use a truthy string instead of expecting a runtime error.
Add C++98 compatibility by introducing explicit casts, replacing C99-specific constructs with macros, and updating the build system to produce C++ object files. Refactor the Value union to a plain uint64_t when WREN_NAN_TAGGING is enabled, adding helper functions for num-to-value and value-to-num conversions. Update the compiler to split emit into emit and emitShort for cleaner bytecode emission, and rename emitByte/emitShort to emitByteArg/emitShortArg.
- Replace Value union with plain uint64_t typedef under WREN_NAN_TAGGING, removing num/bits field access
- Add wrenValueToNum and wrenNumToValue helper functions for double conversion
- Remove wrenValuesEqual function from wren_value.c as bitwise comparison is now direct
- Update Makefile with CPPFLAGS for C++98 compilation and add release-cpp build target
- Add wren-cpp and libwren-cpp.a to .gitignore for C++ build artifacts
Remove the single-purpose `allocate` helper and introduce three type-safe allocation macros (`ALLOCATE`, `ALLOCATE_FLEX`, `ALLOCATE_ARRAY`) that directly invoke `wrenReallocate`. Update all call sites in `wren_value.c` — including `wrenNewSingleClass`, `wrenNewClosure`, `wrenNewFiber`, and `wrenNewFunction` — to use the appropriate macro, eliminating the need for manual sizeof calculations and improving compile-time type checking when compiling as C++.
Add explicit casts to `(Code)` in `debugPrintInstruction` for bytecode indexing, to `(char*)` in `wrenSymbolTableAdd` for heap string allocation, and to `(type*)` in the `DEFINE_BUFFER` macro's reallocation call to ensure C++ compilation compatibility without implicit conversion errors.
- Cast malloc return to char* in src/main.c to avoid C++ implicit void* conversion
- Rename emit to emitByteArg and emitShort to emitShortArg in src/wren_compiler.c to avoid conflict with new emit and emitShort helpers
- Add new emit function taking uint8_t byte and emitShort helper for 16-bit big-endian emission
- Remove stray semicolon in script/test.py
Implement `all(f)` method on Sequence class that returns true if all elements pass the predicate function. Add corresponding documentation entry for `forall(predicate)` in core-library.markdown. Include three test files covering basic functionality, non-boolean return handling, and non-function argument error cases.
Add a new singleton value `VAL_UNDEFINED` to represent globals that have been implicitly declared via forward reference but not yet explicitly defined. Introduce `wrenDeclareGlobal()` to create such entries in the global table, and modify `wrenDefineGlobal()` to check for and resolve undefined slots. Update the compiler's `findUpvalue()` to stop closure capture at method boundaries, preventing methods from closing over local variables. Refactor `wrenSymbolTableAdd()` to always add symbols without duplicate checking, moving that logic to callers. Adjust error messages in the compiler to handle EOF tokens and improve newline formatting. Fix the delta_blue benchmark by renaming the global `planner` variable to `ThePlanner` to avoid shadowing the forward-declared function.
Add support for forward references to top-level variables by implicitly
declaring unresolved capitalized names as globals during compilation.
If a real definition is not found later, a compile-time error is raised.
This enables mutual recursion at the top level and fixes issues #101 and #106.
Introduce an `UNDEFINED` singleton value to mark implicitly declared globals
that have not yet been explicitly defined. Update `wrenDeclareGlobal` to add
such entries, and modify `wrenDefineGlobal` to check for and replace undefined
placeholders. Adjust the symbol table API to allow duplicate additions for
implicit declarations. Add test cases for mutual recursion, forward references
in functions and methods, and undefined variable errors.
Replace the forward-declared `planner` variable with a capitalized `ThePlanner` name across all constraint methods and test functions, removing the TODO comment about forward declarations.
Replace sequential `if` statements with `else if` chains in `readName` so that once a keyword matches (e.g. "break"), the remaining keyword checks are skipped, fixing issue #110 where later keywords could incorrectly override an already-matched token type.
Modify `findUpvalue` in the compiler to return -1 when the enclosing function is a method, preventing closures from capturing outer local variables. Add a new `nonlocal` variable resolution path that treats capitalized identifiers as global variables rather than method receivers. Update existing test files to use capitalized global names and add new test cases for nonlocal assignment, duplicate nonlocal declarations, block scoping, and method-local variable shadowing.
Fix three typos across documentation files: 'unvalid' to 'invalid' in
doc/error-handling.txt, and 'bretheren' to 'brethren' in both
doc/site/expressions.markdown and doc/site/getting-started.markdown
Add the -g compiler flag to DEBUG_CFLAGS in the Makefile to enable
generation of debugging symbols during debug builds, allowing better
debugging with tools like GDB.
Add string type check for IO.read() prompt argument with Fiber.abort on non-string input. Implement stdin piping in test runner via // stdin: comments, allowing tests to provide input lines. Update stack trace filtering to omit built-in library frames with empty source paths. Add io/read.wren and io/read_arg_not_string.wren test cases.
Implement a new static `IO.read(prompt)` method in the IO class that writes a prompt string to stdout and reads a line from stdin into a fixed 1024-byte buffer. The C implementation adds a `MAX_READ_LEN` constant, an `ioRead` function using `fgets`, and registers the method via `wrenDefineStaticMethod`. The builtin source string is updated to include the new Wren method definition.
The nextToken function in wren_compiler.c previously only skipped spaces and carriage returns when advancing past whitespace, causing tab characters to be treated as non-whitespace tokens. This change adds '\t' to the whitespace check in both the initial case statement and the peekChar loop, ensuring tabs are properly skipped like other whitespace characters. A new test file test/whitespace.wren is added to verify correct handling of tabs in various indentation patterns and inline code positions.
Add a new test file `test/ignore_carriage_returns.wren` that sprinkles carriage
return characters (`\r`) in various positions within source code to confirm the
parser correctly ignores them as whitespace. The test includes a deliberate
compile error to validate that line numbering remains accurate despite the
presence of carriage returns.
Add a `contains(element)` method to the built-in `List` class in `builtin/core.wren` and its embedded source in `src/wren_core.c`, enabling linear search for an element. Introduce a new `Set` class example in `example/set.wren` implementing set operations (union, intersection, difference) using the new `contains` method. Update `doc/site/classes.markdown` with a warning against inheriting from built-in types due to internal bit representation constraints.
Change `fopen` mode from `"r"` to `"rb"` in `readFile()` to prevent CRLF-to-LF conversion on Windows, and add `'\r'` as a skipped whitespace character in `nextToken()` to handle carriage returns embedded in source files. This fixes parsing errors when Wren source files use Windows-style line endings.
Add a note to the classes documentation page explaining that inheriting from built-in types (Bool, Num, String, Range, List) is not supported due to internal bit representation conflicts that cause errors when invoking inherited methods on derived types.
Add a complete Set class implementation in example/set.wren with union, intersection, and set minus operations. Implement List.contains method in builtin/core.wren and its C source to support element existence checks via iteration.
When `super` is invoked at the top level without an explicit method name, the compiler previously dereferenced a NULL `enclosingClass` pointer while trying to copy the enclosing method's signature. This change adds a NULL check for `enclosingClass` in the `super_` function, setting an empty method name and zero length when the pointer is NULL, preventing the segmentation fault. Also extends the test file `super_at_top_level.wren` with additional cases for bare `super`, `super.foo("bar")`, and `super("foo")` to verify error handling for these top-level super invocations.
Rename indexOf.wren and startsWith.wren test files to index_of.wren and
starts_with.wren respectively, fix missing trailing newlines, update
string class documentation to clarify UTF-8 storage and move the
note about incorrect UTF-8 handling in the index operator, and
remove unnecessary parentheses in string_indexOf native return.
The font stylesheet link in doc/site/template.html used an explicit http:// scheme,
causing Firefox to block the request on HTTPS pages due to Mixed Content warnings.
Changed to a protocol-relative URL (//fonts.googleapis.com/...) so the browser
automatically uses the same protocol as the parent page.
The `string_subscript` native was allocating a 2-byte buffer for single-character
results, causing a one-byte over-allocation. Changed to allocate exactly 1 byte
for the character plus the null terminator handled by `wrenNewUninitializedString`.
Also fixed `wrenNewUninitializedString` to properly cast the `length` parameter
to `int` when assigning to `ObjString->length`, resolving a potential
truncation warning on 64-bit systems.
Added a test case to verify that subscript access returns a properly formed
string that compares equal to the expected character.
The lexer previously treated a leading minus sign followed by a digit as a single negative number token, which caused incorrect parsing of expressions like `1-1` and broke method calls on negative numbers. This change removes that special case, making the minus sign always a separate token, and updates all test expectations to use explicit parentheses for negative number method calls.
Introduce a `methodNotFound` helper in `wren_vm.c` that parses the symbol name to determine the number of arguments and generates a detailed error message including the argument count. Update all runtime error calls and test expectations across fiber, inheritance, method, and super test files to reflect the new format, and add new test cases for method-not-found with 1, 2, and 11 arguments.
Add a new FAQ entry explaining why Wren uses a stack-based bytecode VM
instead of a register-based one. The entry covers the trade-offs between
the two approaches, references Lua's switch to register-based VM, and
explains that Wren's operator-overloading design makes register-based
optimizations less beneficial.
Add writeObject_ helper that checks if obj.toString returns a String before
writing it, falling back to "[invalid toString]" otherwise. Update print,
write, and printList_ to use the new helper instead of calling toString
directly. Include test cases for both IO.print and IO.write with a class
whose toString returns an integer.
Use the integer length returned by sprintf directly instead of calling strlen on the buffer, eliminating redundant string length calculations in two native functions for number and range string conversion.
The length field in ObjString struct now uses int instead of size_t, saving memory
and aligning with other string length storage conventions throughout the VM.
This eliminates signed/unsigned conversion warnings and matches the type used
elsewhere for string lengths.
Replace strlen(buffer) calls with the length returned directly by sprintf in the
num_toString and range_toString native functions, eliminating unnecessary string
length calculations after formatting.
Replace all uses of `strlen()` and `strcmp()` on string values with the precomputed `length` field and `memcmp()` for equality checks. This eliminates repeated O(n) length calculations in `string_count`, `string_contains`, `string_eqeq`, `string_bangeq`, and `string_subscript`. Also fixes memory accounting in `markString` to use the stored length instead of recalculating it.
Extend the metrics script to walk the benchmark directory, counting benchmark files, TODOs, non-empty lines, and empty lines, and print these new benchmark statistics alongside existing source and test metrics.
Add Travis CI build status badge to README for continuous integration visibility.
Remove trailing semicolons from three assignment statements in delta_blue.wren
benchmark to maintain consistent coding style across the codebase.
Remove unnecessary semicolons from three assignment expressions in the
delta_blue.wren benchmark file to conform to Wren language style conventions,
where semicolons are optional and typically omitted.
Remove separate heap allocation for string text by converting ObjString.value from a char pointer to a C99 flexible array member. This eliminates the extra allocation in wrenNewUninitializedString and the corresponding free in wrenFreeObj, reducing memory fragmentation and pointer indirection for all string objects.
Insert a Markdown image link pointing to the Travis CI build status SVG for the munificent/wren repository, placed between the contribution call-to-action paragraph and the syntax reference link. Also fix the missing trailing newline on the contributing URL line.
The previous implementation relied on sprintf's "%.14g" format for NaN values,
which produces platform-dependent results (some libc versions add a sign prefix).
This change adds an explicit NaN check using the self-comparison idiom (value != value)
and returns a lowercase "nan" string directly, ensuring consistent behavior across
all platforms. The buffer size comment is also updated to remove the now-inaccurate
reference to NaN handling.
Append Paul Woolcock's name and email (paul@woolcock.us) to the list of contributors in the AUTHORS file, following the existing entry for Robert Nystrom.
- Create AUTHORS file listing Robert Nystrom as initial contributor
- Rewrite README to emphasize Wren as concurrent scripting language with fiber examples
- Expand contributing.markdown with structured sections for finding tasks and making changes
- Update index.markdown with call-to-action links for trying and contributing
The `error()` function in the compiler now returns early when the offending token
is of type `TOKEN_ERROR`, preventing the lexer's already-reported error from
being emitted a second time to stderr. This eliminates redundant error messages
for malformed tokens.
Add special handling in the lexer's nextToken function to detect a '#' character followed by '!' on the first line (currentLine == 1) and skip the entire line as a comment. If the shebang appears on any other line, or if a '#' is not followed by '!', emit a lex error for invalid character. Include test cases for valid shebang execution, shebang at EOF, shebang on a non-first line (expected error), and an invalid shebang pattern (expected error).
Remove the empty-line check in runRepl that skipped interpretation for blank input, and refactor the main compilation loop in wrenCompile to use a while loop with TOKEN_EOF matching instead of a for loop with redundant EOF break. This allows the compiler to process files containing only comments or whitespace without prematurely terminating, fixing issue #57. Add test fixtures for comment-only source files.
Add libwren.a and libwrend.a to .gitignore to prevent tracking of static library build outputs, and update the Makefile comment to explain that main.c is excluded from shared library object lists.
Add `libwren.a` and `libwrend.a` static library build targets using `ar rcu`, compile all object files with `-fPIC` for position-independent code, and exclude `main.o` from the shared library object lists via `subst` to allow linking the interpreter separately against the static archive.
Bob Nystrom