Module bigint 

BigInt, the schema’s 64-bit signed integer scalar (ADR 0019).

It is a Copy newtype over i64, not an arbitrary-precision integer; the name is the schema type’s (totalE8 BigInt) and is namespaced as cratestack::BigInt, so it does not collide with num_bigint::BigInt unless one file imports both.

Wire form

On every codec the value is a canonical decimal string: 0, or an optional -, a non-zero digit and at most 18 more digits, inside i64 (JSON Schema pattern ^(0|-?[1-9][0-9]{0,18})$). In JSON that is a JSON string; in CBOR it is a text string (major type 3), never an integer or a bignum tag. One form on every codec means a value that crosses serde_json::Value (the /rpc/batch frames) and then CBOR keeps the same bytes, and no JavaScript number ever holds it.

Serialize writes that string. Deserialize accepts nothing else: a JSON number, a CBOR integer, a CBOR tag 2 or 3, +5, 007, -0, " 1" and anything outside i64 are all refused, because a number above 2^53 may already have been rounded by the JavaScript that produced it and the server cannot tell.

Arithmetic

Checked methods only (BigInt::checked_add, BigInt::checked_sub, BigInt::checked_mul). There are no operator impls, because an operator on a 64-bit money value must panic, wrap or invent an error path, and no Deref, because with one a call site nobody updated would keep compiling against i64 methods. A missed call site is a compile error.

Database support

The sqlx-postgres and rusqlite Cargo features add the driver trait impls (Type, Encode, Decode, PgHasArrayType; ToSql, FromSql) so a BigInt primary or foreign key can be bound and read directly. Each delegates to i64 (INT8 / SQLite integer). Neither is on by default and cratestack-core takes no non-optional dependency on either driver; the backend runtimes enable the one they need.

Structs

BigInt

A signed 64-bit integer that travels as a canonical decimal string on every codec. See the module documentation for the wire form.

ParseBigIntError

Why a string is not a canonical BigInt.