Struct FnChunk 

pub struct FnChunk {
    pub name: String,
    pub arity: u8,
    pub local_count: u16,
    pub code: Vec<u8>,
    pub constants: Vec<NanValue>,
    pub effects: Vec<u32>,
    pub thin: bool,
    pub parent_thin: bool,
    pub leaf: bool,
    pub no_alloc: bool,
    pub source_file: String,
    pub line_table: Vec<(u16, u16)>,
}

A compiled function chunk — bytecode + metadata.

Fields

name: String

arity: u8

local_count: u16

code: Vec<u8>

constants: Vec<NanValue>

effects: Vec<u32>

Declared effects (e.g. ! [Console.print, Http]). Empty for pure functions.

thin: bool

Conservatively classified “thin” function: likely to return without creating any frame-local heap survivors or dirtying globals.

parent_thin: bool

Narrow wrapper-like helper that borrows the caller young region and skips ordinary-return handoff as long as it stays out of yard/handoff.

leaf: bool

Leaf function: no CALL_KNOWN or CALL_VALUE in bytecode (only builtins and opcodes). When also thin and args-only (local_count == arity), can be called without pushing a CallFrame.

no_alloc: bool

Pure no-alloc function (per shared ir::compute_alloc_info under VmAllocPolicy): the body never produces a heap object. Disjoint from thin because mutual-TCO peers can be no-alloc but not bytecode-thin. TAIL_CALL_KNOWN skips finalize_frame_locals_for_tail_call when the target chunk has this flag set — the runtime guard is guaranteed to be a no-op for pure no-alloc bodies.

source_file: String

Source file path for this function (empty for synthetic/unknown).

line_table: Vec<(u16, u16)>

Run-length encoded line table: (bytecode_offset, source_line). Sorted by offset. Lookup: find last entry where offset <= target ip.

Trait Implementations

impl Clone for FnChunk

fn clone(&self) -> FnChunk

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for FnChunk

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.