A review found the 0.1.0 companion lossy for documents that are valid today. Its
claim to preserve the manifest's canonical roots was false three ways:
A canonical blob had no representation at all. blob_roots referenced by
canonical operations or reduced state ARE canonical roots, and the document
structure had no blob line. An embedded image, font or recording would vanish
from a projection silently -- the operations referencing it still there,
pointing at a blob id the text no longer contained.
An ExtensionDeclaration lost its semantic version and its affected_object_kinds
outright, and left its preserved_chunk_roots undefined.
ProfileId::Custom(ProfileRegistryId) was unrepresentable: a symbol was required
where sixteen registry bytes are carried.
All three share one cause I had not named. A ChunkRef and a BlobRef are PHYSICAL
references -- offset, compressed length, compression -- which the projection may
not preserve; and they carry DERIVABLE identities -- ChunkId, ContentHash, BlobId
-- which it may not duplicate. Having no rule for either, I dropped the
references and took their contents with them.
req:textproj:derive-or-carry states it, and it is the same rule
req:textproj:reduced-state-derived already applied one level up: carry exactly
what the document does not determine, and nothing it does. Physical attributes
never appear; derivable identities never appear; content and semantic attributes
always do. The one non-derivable identity in schema major 0 is SnapshotId, which
the Binary Format companion pins as opaque and forbids readers to derive -- an
exception for a stated reason rather than an oversight. The grammar now visibly
contains no offset, no length, no compression, no chunk id, no hash, no blob id.
So: req:textproj:canonical-blobs (canonical blobs projected, non-canonical ones
not), req:textproj:profile-id ((custom #x...)), req:textproj:extension-declaration
(every field; chunks as kind + schema + payload, never as a ChunkRef -- the
projection has no file to point into), and req:textproj:base-snapshot-inline
extended to say what the inlined payload IS and that the root ChunkRef and the
SnapshotRef hash are re-derived from hash(Snapshot, schema, payload), never read.
The gap started upstream. core_spec's own list of what the projection preserves
omitted canonical blobs while classifying blob_roots as canonical roots -- an
inconsistency inside one document. Corrected there, along with withdrawing the
permission to reference a base snapshot "externally", which the inline
ratification had already made untenable.
Also: the generated PDF metadata and page header still said Operation Catalog,
inherited from the copied preamble.
The four 0.1.0 ratifications stand unchanged. Implementation stays deferred: a
gate that is lossy is not a gate.
Gate: clippy 0, 31 targets / 1031 passed / 0 failed, conformance 8/8, zero golden
churn; core_spec, binary_format, operation_catalog and text_projection all build
with no undefined references.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Levi Neuwirth
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