Previously, the lexer greedily consumed a `-` followed by a digit as a single negative number token, causing "1 -1" to be lexed as two number tokens instead of a minus operator and a positive literal. This broke parsing of subtraction expressions without spaces.
Now `-` always emits a TOKEN_MINUS, and the parser handles unary negation. This is a breaking change: `-16.sqrt` is now parsed as `-(16.sqrt)` instead of `(-16).sqrt`, requiring parentheses for negative method receivers. All number method tests (abs, ceil, floor, sqrt, toString) are updated to use explicit parentheses for negative receivers.
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()`.
Remove "(bob)" author prefix from all TODO comments in benchmark/method_call.wren, include/wren.h, src/main.c, src/wren_common.h, src/wren_compiler.c, src/wren_core.c, src/wren_value.c, src/wren_value.h, and src/wren_vm.c. Update the TODO_PATTERN regex in metrics script to match the new format without author parentheses. Also refactor test file counting in metrics to use os.walk with fnmatch for recursive directory traversal instead of glob.iglob.
Implement unary negation for numbers and logical not for booleans, introduce PREC_ASSIGNMENT and PREC_UNARY precedence levels, refactor parse functions to accept allowAssignment parameter, add assignment tests for global/local/chained/error cases, and update if-syntax to support statement branches and assignment in conditions.
Implement equality and inequality operators across three primitive types in the compiler and runtime. Add `bool_eqeq`/`bool_bangeq`, `num_eqeq`/`num_bangeq`, and `string_eqeq`/`string_bangeq` primitives that return false/true respectively when comparing against incompatible types. Update the parse rule table with `INFIX_OPERATOR` macros for `TOKEN_EQEQ` and `TOKEN_BANGEQ` at `PREC_COMPARISON` precedence. Include test files `bool_equality.wren`, `number_equality.wren`, and `string_equality.wren` covering cross-type comparisons and edge cases.
Implement parenthesized expression parsing in the primary() function by matching TOKEN_LEFT_PAREN, recursively calling expression(), and consuming TOKEN_RIGHT_PAREN. Add grammar test cases in test/grammar.wren verifying correct operator precedence with parentheses, including nested grouping expressions.
