Struct NovaStr 

#[repr(C)]
pub struct NovaStr {
    pub len: u64,
    pub ptr: *const u8,
}

A Nova string value: immutable UTF-8, { len, ptr }.

A runtime-made String or Bytes value is one leaf GC object: this header at offset 0, and its bytes inline at offset 16, where ptr points ([alloc_str_object]). A string literal’s header from nova_rt_str_new is a 16-byte leaf whose ptr targets static data.

Invariant: ptr never points into another GC object. Every header is a leaf, so the collector never traces ptr. A header that pointed into a different GC object would not keep it alive. A future zero-copy slice or view must not reuse this type with a leaf header. Only [alloc_str_object] and nova_rt_str_new write a ptr, and nothing in this crate’s production code calls nova_rt_str_new. The test only_the_two_builders_write_a_novastr_ptr checks both by scanning the source text; its doc names some of what such a scan cannot see. What the code generators pass to nova_rt_str_new rests on its # Safety contract.

A convention, not an invariant: [gc_str_filled]’s fill does not allocate GC memory. Memory safety does not depend on it, since the new object stays reachable from gc_str_filled’s own frame across fill. It keeps fill cheap, and its liveness argument to the one allocation before it. Every current writer only calls [Fill::put].

Fields

len: u64

ptr: *const u8