bear/vm/types.v

// types.v — core types and constants for the VuurRaaf VM.
module vm

import obj

const stack_cap = 65536

// Field is one `name: value` entry of a struct value.
struct Field {
mut:
	name string
	val  i64
}

// StructVal is a struct (or map) value. `fields` keeps insertion order for
// rendering and JSON encoding; `by_name` is a hash index for O(1) field
// lookup by name, so map-style access on large records stays fast.
struct StructVal {
mut:
	fields  []Field
	by_name map[string]int // field name -> index into fields
}

// Handler records a try/catch handler pushed at runtime.
struct Closure {
	entry int // code IP of the function body
mut:
	captured []i64 // values of the enclosing locals this closure captures (by value)
}

struct Handler {
	ip int // catch_ip
	bp int // frame base at try point
	sp int // stack pointer right after the handler record
}

struct Vm {
mut:
	code       []u8
	strings    []string
	arrays     [][]i64
	structs    []StructVal
	floats     []f64
	closures   []Closure
	stack      []i64
	sp         int
	bp         int
	ip         int
	trace      bool
	halted     bool
	prog_args  []string
	exit_code  i64
	did_exit   bool
	handlers   []Handler
	lines      []obj.LineInfo // debug info: code offset -> source line
	fns        []obj.BinFn    // function table (for stack traces)
	const_strs int            // strings[0..const_strs] are bytecode constants, never collected
	last_heap  int            // heap size at the last GC check (allocation trigger)
	build_root string         // directory of the .vrmm build module (build_root() builtin)
}

fn bool_i64(b bool) i64 {
	return if b { i64(1) } else { i64(0) }
}