A bytecode VM interpreter for Lox

Usage

Interpret a lox file. A lox file must have .lox extension. Some sample programs are provided in the programs folder.

loxz <OPTIONS> <file.lox>

Run in REPL mode

loxz <OPTIONS>

Flags:

Flag	Description
-h, --help	Show help message
-t, --stack-tracing	Enable VM stack tracing
-d, --debug	Enable debug output, set debug level

Additional features in loxz over the standard implementation:

• Flexible constant pool upto 16_777_216 (u24) constants enabled by OP_CONSTANT_LONG. This instruction is emitted only after 8-bit space for constants have been exhausted. pool have been exhausted.
• 65536 Global variables supported over 256 in clox, with a global cache to speed up lookups.
• Expanded Local variables limit to 65536 (u16), no 256 local variable limit, this means we use (u16::max + 1024)*sizeof(Value) [16 bytes] for stack
• String interning for strings are performed at comptime so zero cost runtime ObjString comparisons. They are only a pointer comparison. It's as fast as it gets.
• Supports % modulo operation.
• Add support for switch/case. Check out switch-case.lox example. Supports upto 64 nested switch blocks. No break keyword required, only one switch case executes.

Native Functions

The interpreter includes several built-in native functions with runtime error reporting:

• clock() - Returns the current timestamp in seconds since epoch
• sqrt(number) - Returns the square root of a number (requires non-negative input)
• abs(number) - Returns the absolute value of a number
• pow(base, exponent) - Returns base raised to the power of exponent

All native functions perform argument validation and provide descriptive error messages for invalid inputs. See test_native.lox for usage examples.