Rename the IO.write method to IO.print, which now prints without a trailing newline, and add a new IO.print method that appends a newline after output. Update all benchmark, example, and test files to use IO.print instead of IO.write. Additionally, implement Unicode escape sequence parsing in the compiler's string tokenizer, supporting \uXXXX and \u{...} syntax with proper UTF-8 encoding for code points up to U+10FFFF.
Replace the global `io` singleton object with a static `IO` class, moving the `write` native from the instance to the metaclass. Update all benchmark, example, and test files to use `IO.write()` instead of `io.write()`.
Add closure objects that wrap functions with captured upvalues, enabling
first-class closures that close over local variables from enclosing scopes.
Introduce new bytecode instructions (CODE_CLOSURE, CODE_LOAD_UPVALUE,
CODE_STORE_UPVALUE, CODE_CLOSE_UPVALUE, CODE_RETURN) and a CompilerUpvalue
tracking system with a MAX_UPVALUES limit of 256. Refactor the grammar to
strictly separate statements from expressions, fixing a bug where block
expressions incorrectly popped locals while temporaries remained on the
stack. Rename internal functions (wrenCallFunction, wrenDebugDumpInstruction,
wrenDebugDumpStack) and add Upvalue allocation, closure creation, and
debug dump support for the new instructions.
Add TOKEN_PIPEPIPE token for '||' syntax, implement or() parsing function with CODE_OR bytecode, and add VM interpreter logic that short-circuits on truthy left operand. Update .gitignore to exclude *.xccheckout files, extend test coverage for falsy behavior in and.wren and if.wren, and add comprehensive or.wren test suite verifying short-circuit semantics and truthiness rules.
Introduce Scope struct and PUSH_SCOPE/POP_SCOPE macros to manage nested variable scopes during compilation. Update declareVariable to distinguish global declarations from local ones based on scope presence rather than parent compiler. Add truncateSymbolTable helper to clean up local symbols when exiting a scope. Include new test files verifying scoped variable isolation in if, while, and block constructs.
Add TOKEN_WHILE to the token enum and keyword lookup in the compiler, enabling the parser to recognize 'while' statements. Introduce the CODE_LOOP opcode in the VM for backward jumps, and implement the patchJump helper to resolve forward jump offsets during compilation. Include comprehensive test cases for while loops covering single-expression bodies, block bodies, newline handling, and null result semantics.
