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.
Remove the `;` case from the `nextToken` function in `wren_compiler.c` so that semicolons are no longer lexed as `TOKEN_LINE`. Update the documentation in `doc/site/syntax.markdown` to describe newlines as the sole statement separator, and adjust all test files (`test/limit/many_constants.wren`, `test/limit/many_globals.wren`, `test/limit/too_many_constants.wren`, `test/semicolon.wren`) to reflect that semicolons now produce an error instead of being treated as line breaks.
The anonymous union inside the Method struct was previously unnamed, which is not allowed in strict C99 mode. This change names the union `fn` and updates all references to its members (`.primitive`, `.foreign`, `.obj`) to use the qualified syntax (`.fn.primitive`, `.fn.foreign`, `.fn.obj`). The NATIVE macro parameter was also renamed from `fn` to `function` to avoid shadowing the new union field name.
Add .travis.yml with gcc and clang compilers running make && make test.
Modify script/test.py to call sys.exit(1) when any tests fail, ensuring
CI build correctly reports failure status.
- Introduce Wren as a small, clean, fast class-based scripting language
- Include code example demonstrating class syntax with adjectives list
- List key features: small codebase under 4000 semicolons, clean C99 implementation, fast single-pass compiler, class-based object model, embedding-focused design
- Provide links to source code, NaN tagging implementation, performance benchmarks, class documentation, and embedding API
The link target for the embedding API reference was pointing to the wrong
filename (`embedding.html` instead of `embedding-api.html`), causing a 404
error when users clicked the link. This commit updates the href to match the
actual generated documentation file.
Add a new `gh-pages` make target that depends on the `docs` target and copies the generated documentation from `build/docs/` into a local `gh-pages/` directory. Also update `.gitignore` to exclude the `gh-pages/` directory, which is intended to be a separate checkout of the repository for pushing to GitHub Pages.
- Inserted a TODO comment before the toString native binding in the
function class initialization to remind about implementing an arity
getter for Wren functions.
Implements a new `Fiber.abort()` static method that allows a fiber to terminate with a custom error message string. The method validates that the argument is a string, then returns a PRIM_ERROR to abort the current fiber. Includes three test cases: basic abort with error message retrieval via `fiber.try`, aborting the main fiber with a runtime error, and type checking that non-string arguments produce an appropriate error message.
Consolidate the two separate conditional branches for empty range on zero-length list into a single expression using ternary on range->isInclusive, removing the TODO comment and reducing code duplication.
Migrate fiber stack management from an integer `stackSize` counter to a direct `Value* stackTop` pointer, eliminating repeated `stack[stackSize - 1]` calculations. Update all stack slot accesses, iteration loops, and the `CallFrame::stackStart` field to use pointer arithmetic, simplifying the code and reducing index arithmetic overhead.
Store the start of the current frame's stack in a local `stackStart` variable
during LOAD_FRAME() macro execution, replacing repeated calculations of
`fiber->stack[frame->stackStart + offset]` with `stackStart[offset]` across
LOAD_LOCAL and LOAD_FIELD opcodes. Also remove unused `upvalues` register
variable and its assignments from closure handling paths.
The performance numbers in the documentation's benchmark chart have been refreshed to reflect the latest measurements. Method call results now show wren at 5100 (up from 4930), luajit at 4441 (up from 4266), ruby at 2868 (up from 2752), lua at 1742 (up from 1728), python3 at 884 (up from 865), and python at 779 (up from 764). DeltaBlue results show wren at 7006 (up from 6662) and python3 at 2333 (down from 2336).
Move the class pointer from ObjInstance into the base Obj struct and remove the separate metaclass field from ObjClass, allowing all heap objects to directly reference their class. Add an inlined wrenGetClassInline function in the header to eliminate function call overhead during method dispatch, yielding 10-43% performance gains across benchmarks.
Introduce nine new bytecode instructions (CODE_LOAD_LOCAL_0 through CODE_LOAD_LOCAL_8) that directly encode the local slot number in the opcode itself, eliminating the need to read and decode a separate argument byte for the most frequently accessed local variables. This optimization targets the hottest path in the interpreter, as LOAD_LOCAL is the most executed instruction across benchmarks (e.g., 3.75M times in delta_blue). The compiler's `loadLocal` helper emits the specialized opcode when the slot index is ≤8, falling back to the generic `CODE_LOAD_LOCAL` with an argument byte otherwise. The VM dispatch table and debug printer are updated accordingly. Benchmarks show consistent speedups: fib +7.3%, method_call +5.9%, binary_trees +1.9%, for +2.8%, delta_blue +1.0%.
Add a new test file `test/limit/too_many_constants.wren` containing a single function with 8195 integer literal constants to verify the compiler correctly rejects functions that exceed the maximum constant count limit.
In `getNumArguments`, add a `return 0` after the `UNREACHABLE()` default case to prevent
undefined behavior when assertions are disabled. In `wrenGetClass`, reorder the
`UNREACHABLE()` macro before the `return NULL` so the unreachable annotation is
always emitted. In `runInterpreter`, replace the `ASSERT(0, ...)` with an explicit
`UNREACHABLE()` and `return false` to guarantee a return value on all control paths
when the interpreter exits unexpectedly.
Add -lm flag to both debug and release linker commands in Makefile to resolve
undefined math library references. Define _GNU_SOURCE in main.c to make getline()
available under GCC. Add default cases to switch statements in runFile and
getNumArguments to suppress -Wswitch warnings. Fix u_int8_t to uint8_t type in
wrenNewFunction declaration and definition for POSIX compliance.
Implement a new `Fiber.try()` method that allows a calling fiber to catch runtime errors from a called fiber. When a fiber is invoked with `try()` instead of `call()`, any runtime error that occurs in the called fiber is returned as a string to the caller rather than terminating the program with a stack trace. The `callerIsTrying` flag on `ObjFiber` tracks this state, and the `runtimeError` function now checks this flag to redirect the error to the caller's stack. Also adds `Fiber.error` getter to retrieve the error string from a failed fiber, changes `Fiber.isDone` to return `true` for errored fibers, and migrates the fiber error field from a raw `char*` to an `ObjString*` for proper memory management. Includes comprehensive test cases for try behavior, re-entry prevention, and error state queries.
Replace the empty `core-libraries.markdown` placeholder with a comprehensive `core-library.markdown` documenting Object, Class, Bool, and Fiber classes. Update site template to link to the new page. Tweak SCSS styles: reduce body font to 16px/25px, darken header background with text-shadow, adjust code font size and borders, add left margin to main content paragraphs and pre blocks, and refine link colors. Fix prose in functions.markdown to use "arguments" instead of "parameters" and clarify dynamic dispatch wording.
The crash occurred in captureUpvalue() when an upvalue for an earlier local
variable was captured after a later one. The function walked to the end of the
open upvalue list but then dereferenced a NULL pointer when comparing
upvalue->value against the target local slot.
Added a NULL guard before the equality check so that if no existing upvalue
is found, the function correctly proceeds to create a new one instead of
dereferencing a null pointer.
Also fixed a typo in the comment ("existsing" -> "existing").
Added regression test close_over_later_variable.wren that exercises the
scenario of capturing upvalues for locals in reverse declaration order.
Add a 64-character maximum identifier length with compile-time error reporting, and enhance the runtime field overflow error to include the class name and remove the TODO comment. Update test expectations for both limit scenarios.
Refactor benchmark runner to store results in a nested dict keyed by language name, enabling per-benchmark result aggregation. Add bar chart HTML tables to doc/site/performance.markdown displaying method call, DeltaBlue, and binary trees benchmarks across languages. Include SCSS styles for chart layout, bar coloring, and main content padding.
Add a new test case `shadow_closure_with_local.wren` that verifies a closed-over
variable can be shadowed by a local variable in an inner scope within the same
closure. The test ensures that the outer closure variable retains its value
outside the inner scope after the shadowing local goes out of scope.
Also remove an incomplete TODO comment from `reuse_closure_slot.wren` and add
a detailed TODO comment in `wren_compiler.c` discussing the design trade-off
between treating capitalized names as globals versus implicit `this` calls
when walking the scope chain.
Add test cases for super calls with different argument arities to verify correct method dispatch to the superclass. Also add a test for runtime error when calling a non-existent superclass method, and remove the TODO comment for that case.
Add a static `print` method with no arguments that writes only a newline, enabling blank-line output. Remove the `ignoreNewlines` calls before closing parentheses in parameter lists and method calls, tightening syntax rules. Add a `strlen` TODO comment in symbol table lookup for future optimization. Move the `Foo.toString` test from `test/io/write.wren` to `test/io/print.wren` and delete the old write test file.
The truth.wren test file is relocated from test/if/ to test/for/, and the test logic is rewritten to use a custom Iter class with for-in loops instead of if statements, while preserving the same truthiness assertions for false, null, true, 0, and empty string values.
Add `^category` front matter to branching, classes, error-handling, fibers, functions, lists, looping, maps, method-calls, performance, and qa markdown files. Create new placeholder pages for contributing, core-libraries, and embedding-api under reference category. Remove old embedding and getting-involved pages. Change all `:::wren` code block annotations to `:::dart` across multiple documentation files. Update index title from "Welcome" to "Welcome!" and fix a typo in the Wren class example string. Refine performance page wording for clarity.
Add `^category` front matter to all language, types, and reference doc pages for site navigation restructuring. Replace `:::wren` and `:::java` code block annotations with `:::dart` across multiple files. Create new stub pages for core-libraries, embedding-api, and contributing under the reference category. Remove the old embedding and getting-involved stub pages.
Add new `fiber.call` method that remembers the calling fiber for symmetric transfer, while `fiber.run` now performs tail-call style switching without preserving the caller. Introduce re-entrancy guards preventing a fiber from being called multiple times, update all test fixtures to use the new API, and add comprehensive test coverage for call semantics including direct/indirect re-entrancy, value passing, and finished fiber errors.
Replace fixed-width `.page` with `max-width`, add `padding` to body, and introduce two breakpoints (639px and 479px) that adjust nav gutter, header centering, and main margin. Convert `.header`, `.content`, `.nav` divs to `<header>`, `<main>`, `<nav>` tags, add viewport meta tag, and hide GitHub ribbon on small screens.
Add a comprehensive Getting Started guide covering Unix/Mac installation via git clone and make, interactive mode usage with code examples, and script execution with a Mandelbrot fractal demo. Also update the site navigation template to link the new page, add placeholder pages for Embedding, Error Handling, and Getting Involved, fix the index page link from "usage.html" to "embedding.html", and reorder the types section in the nav to list Fibers before Functions.
Add 15 static overloads of IO.print in builtin/io.wren and src/wren_io.c, each delegating to a new private printList_ method that iterates over a list of objects. Update all benchmark and test files to use the new multi-argument syntax, removing explicit .toString calls and string concatenation. Add a comprehensive test/io/print.wren verifying single-argument return value, multi-argument null return, and concatenation of up to 16 arguments.
Replace legacy setter syntax `property = value { ... }` with the modern
`property=(value) { ... }` form across all five property setters in the
Variable class (determinedBy, mark, walkStrength, stay, value).
- Replace silent null return with explicit string type check in string_plus native
- Remove outdated TODO comments about string coercion from both num_plus and string_plus
- Add test for basic string concatenation ("a" + "b")
- Add test verifying runtime error when concatenating string with non-string ("a" + 123)
Enforce syntactic requirement for parentheses in operator method signatures (e.g., `+(other)` instead of `+ other`) and setter definitions (e.g., `bar=(value)` instead of `bar = value`). Update the compiler's `infixSignature`, `mixedSignature`, and `namedSignature` functions to consume explicit `(` and `)` tokens around parameter names. Migrate all built-in core library operator definitions and test fixtures to the new parenthesized syntax.
Add `list_instantiate` native to create empty lists, bind it to List's metaclass for `new` support, and remove the related TODO. Also change three `inline` functions in `wren_value.h` to `static inline` to prevent linker errors. Include a new test `test/list/new.wren` verifying `new List` yields an empty list that supports `add`.
Move the wrenIsBool and wrenIsObjType function definitions from wren_value.c
into wren_value.h as inline functions, eliminating function call overhead.
Also relocate OBJ_VAL macro definition to appear before its first use in the
header and add inline for wrenObjectToValue. This yields 3-13% speedup across
benchmarks (binary_trees, delta_blue, fib, for, method_call).
The internal PinnedObj type was renamed to WrenPinnedObj across the codebase to make it publicly accessible, as the WREN_PIN macro expands to stack allocations of this type that must be visible to external consumers. Updated all typedefs, function signatures, and variable declarations in wren_vm.c and wren_vm.h to use the new prefixed name, and removed the TODO comment about moving the struct into wren_vm.c.
Rename boolean defines from `true`/`false` to `1`/`0` for consistency, prefix debug flags with `WREN_DEBUG_`, add `WREN_USE_LIB_IO` flag to guard IO library loading, and wrap IO module includes and function declarations in conditional compilation blocks.
Replace the nested `SymbolTable` struct (containing a `StringBuffer names` field) with a direct `typedef StringBuffer SymbolTable`, updating all internal accesses from `symbols->names.data` to `symbols->data` and `symbols->names.count` to `symbols->count`. Rename `vm->methods` to `vm->methodNames` and `vm->globalSymbols` to `vm->globalNames` across the codebase, including debug printing, compiler symbol resolution, core initialization, and VM interpreter error messages. Remove the stale TODO comment about error codes in `wren.h` and adjust the `instantiate` method name to include a leading space to prevent direct user invocation.
Fix missing space between 'false' and 'for' in the reserved words example
on the syntax documentation page. Also capitalize 'Method calls' to
'Method Calls' and 'Error handling' to 'Error Handling' in the template
navigation sidebar for consistent title casing.
Replace the static `Value globals[MAX_GLOBALS]` array in WrenVM with a dynamic `ValueBuffer` that grows on demand, removing the 256-global limit. Introduce `wrenDefineGlobal()` helper that adds a named global to the symbol table and stores its value in the buffer, returning -2 when the 65536 limit is reached. Update all global access sites (compiler emit, runtime interpreter, GC marking, debug disassembly, core class definition) to use the buffer's data pointer and short (16-bit) opcode arguments instead of byte-sized ones. Add a regression test `many_globals.wren` that defines 8200 globals to verify the new capacity.
Add `addAll(other)` method to the List class in both the Wren core library source and its embedded C string representation. The method iterates over the given `other` sequence, appends each element to the list using the existing `add()` method, and returns the original `other` argument to match the documented return behavior. Include a new test file `test/list/add_all.wren` covering basic appending, empty iterable, range input, and return value verification.
- Delete doc/site/style.css and add doc/site/style.scss with Sass variables, Dosis header font, box-sizing, absolute header positioning, and link hover effects
- Update template.html to reference Dosis font, lowercase nav headings, and change tagline to "a classy little scripting language"
- Add .sass-cache/ to .gitignore and rename Makefile phony target from docs to builtin
- Modify generate_docs.py to compile style.scss via sass subprocess instead of copying static CSS
- Tweak performance.markdown and qa.markdown for minor wording improvements
Replace the placeholder TODO stub with full documentation covering function creation, block arguments, parameters, closures, and usage patterns. The new content includes examples of block argument syntax, method definitions accepting functions, and passing existing function objects as arguments.
Refactor fiber creation from a static `Fiber.create` method to a constructor-based `new Fiber` pattern. This introduces a `fiber_instantiate` native that returns the Fiber class itself, allowing `new Fiber` to invoke `fiber_new` for validation and creation. A shared `validateFn` helper is added to centralize function argument checking, replacing inline validation in both `fiber_new` and `fn_new`. All test files are updated to use the new syntax, and the old `create_wrong_arg_type` test is replaced with `new_wrong_arg_type`.
Add type checking to the `fn_new` native function to ensure the argument
passed to `Fn.new` is either a function or closure. Previously, passing
an invalid type like an integer would silently succeed. Now it returns
a clear runtime error message: "Argument must be a function."
Also remove two stale TODO comments about newline handling in the
compiler that were no longer relevant to current parsing logic.
This change shifts newline tokenization from the lexer's readRawToken into the parser's nextToken, allowing the grammar to selectively ignore newlines in specific contexts (e.g., after operators like "|", "is", "for", "if", "while") while treating them as errors in others (e.g., after "var", "new", "class", "static", before commas in lists). The lexer now emits TOKEN_LINE for semicolons and newlines uniformly, and the parser decides which to elide. Test files are updated to reflect the new error expectations and to remove tests for newlines that are now grammatically allowed.
Refactor `finishBlock` in `wren_compiler.c` to detect single-expression bodies (no newline after `{`) and leave a value on the stack, enabling implicit returns for methods and functions. Add `finishBody` wrapper to handle constructor flag. Update all benchmark and test `.wren` files to remove explicit `return` keywords from getters and single-expression methods, relying on the new implicit return behavior. Remove old `return_null_if_brace.wren` test, add `newline_body.wren`, `newline_in_expression_block.wren`, and `no_newline_before_close.wren` tests for edge cases.
Remove the TOKEN_FN enum value, its keyword mapping in readName, and the
associated function syntax handling from the tokenizer. Also clean up
unnecessary operator tokens from the newline-skipping switch in nextToken
to simplify the token processing logic.
Replace all occurrences of the old `fn` function literal syntax with the new `new Fn {|params| body}` block syntax across benchmark, test, and source files. Update the Wren compiler to handle the pipe operator as a block argument delimiter by removing `TOKEN_PIPE` from the newline-swallowing token list and adding explicit newline matching in `infixOp`. Adjust test expectations in `conditional/precedence.wren` to remove `fn`-based expressions and update `test/assignment/local.wren` to use the new syntax.
Refactor the 'new' operator compilation to emit a method call to 'instantiate' on the class instead of using a dedicated bytecode instruction. This allows built-in types like Fn to override instantiation behavior, enabling `new Fn { ... }` to return the block argument directly. Remove the CODE_NEW opcode from the VM, compiler, and debug printer, and add native methods `class_instantiate`, `fn_instantiate`, `fn_new`, and `object_instantiate` to handle the new dispatch. Update test files to reflect the renamed `Function` class to `Fn`.
Update all fiber test files to replace `Fiber.create(fn { ... })` with `Fiber.create { ... }` block syntax, and add compiler support for parsing block bodies without requiring a newline after the opening brace. The compiler changes include removing `TOKEN_LEFT_BRACE` from the newline-discarding token list and adding `match(compiler, TOKEN_LINE)` calls in `finishBlock`, `methodCall`, `function`, and `block` to handle empty block bodies and inline expressions.
Replace two static error-reporting functions with a single RUNTIME_ERROR macro that stores the fiber frame before calling runtimeError and returning false. This consolidates error handling logic and prepares for catching runtime errors from other fibers by ensuring consistent frame preservation.
In the interpreter's NEW opcode handler, check if the top-of-stack value is a class before attempting construction. If not, raise a runtime error with a descriptive message instead of silently failing or crashing.
Also add a test case (test/new_on_nonclass.wren) that verifies the error is correctly triggered when calling new on a non-class value like an integer.
Implement num_bitwiseAnd and num_bitwiseOr native methods that cast operands to uint32_t before applying bitwise operations, matching the existing bitwiseNot pattern. Register both operators on the number class and add test files covering basic cases, max u32 boundary, overflow behavior, and non-numeric operand error handling.
Add ObjClass parameter to methodNotFound function to display the receiver's class name in runtime error messages, replacing the generic "Receiver" placeholder with specific class names like "Foo" or "Bar metaclass". Update all call sites in runInterpreter to pass classObj, and adjust existing test expectations plus add a new static_method_not_found.wren test for metaclass error messages.
Add two TODO comments to `doc/site/classes.markdown` noting the need to document static methods and to refactor the relationship between method-calls and classes documentation. Also add a matching TODO to `doc/site/method-calls.markdown` to coordinate the refactoring of both pages into using and creating classes.
Swap the order of the site name and page title in the HTML `<title>` tag from "Wren - {title}" to "{title} – Wren", ensuring the specific page title appears first when multiple tabs are open in the browser.
Register TOKEN_PIPE and TOKEN_AMP as infix operators with PREC_BITWISE precedence in the grammar rules table, replacing their previous UNUSED entries. Add corresponding method definitions and test expectations for the `&` and `|` operators in the operator overloading test suite.
Update all lowercase `io` references to uppercase `IO` in doc files including
implicit fields, receiver-less calls, branching, method-calls, syntax, and
variables documentation to match the Wren language's actual API casing.
Bob Nystrom