Elamur Groupantsonto-zip-entry-read
The groupant beside onto/src/zip.rs in the Mova repository: what the code computes, what it never does, how to go back from its outputs, its invariants, cost and checks.
Facts
Implementation material. A Mova code model describes this code at one source revision: partial models, finite checks and their stated scope. It is not a reviewed general exposition, and its labels are shown as written, never raised.
Components
| component | label | where |
|---|---|---|
| approximant | partial | approximant |
| ast | partial | ../syntax.json |
| composition | partial | composition |
| cost | partial | Cost |
| descriptant | present | descriptant |
| invariant | partial | model.md |
| tests | executed bounded checks | tests |
Obernants
The typed relations around the forward model: the behaviour complement (what the code never does), the reverse reconstruction (every input compatible with an output) and specialised views.
| id | type | label | where |
|---|---|---|---|
behavior_complement | behavior_complement | partial source derived model | behavior_complement |
reverse_reconstruction | reverse_reconstruction | partial source derived model | reverse_reconstruction |
lookup_priority | lookup_priority | partial source derived model | lookup_priority |
byte_offsets | byte_offsets | partial source derived model | byte_offsets |
decode_order | decode_order | partial source derived model | decode_order |
allocation | allocation | partial source derived model | allocation |
Model text
descriptant
onto-zip-entry-read
e=first entry name; start=e.off+30+local_namelen+local_extralen; raw=data[start..start+csize]. Require local magic; method0 copy or8 inflate else error; require |out|=size.
Epoch 2026-10-31: source byte range [2524,3551) with source and range hashes, sharing parent lexical AST. Partial source-derived scope, no semantic proof.
approximant
Scoped forward relation
e=first entry name; start=e.off+30+local_namelen+local_extralen; raw=data[start..start+csize]. Require local magic; method0 copy or8 inflate else error; require |out|=size.
Scope bytes [2524,3551) only. Preconditions and exceptions in this scope's catalog; no claims for parent orchestration.
Executable approximant gap: no useful percentage metric established for these categorical/effectful observations. No surrogate or production substitution. Future caps 1/2/5/10% require a metric/domain and evidence; no numerical error bound follows here.
invariant
Scoped observations
On in-bounds headers unknown method/size mismatch cannot succeed. CRC/header disagreement and panic before method gate remain allowed observations.
Cost
O(entries) name search plus compressed/decompressed bytes; stored copy or size-based deflate reservation, no decompressed-size cap before final equality check.
composition
Scope contribution
e=first entry name; start=e.off+30+local_namelen+local_extralen; raw=data[start..start+csize]. Require local magic; method0 copy or8 inflate else error; require |out|=size.
This fragment contributes only entry-read. Parent owns input acquisition, surrounding dispatch and downstream joins. Complement and compatible antecedents are scoped in models.md rather than copied parent statements.
models
behavior_complement
On in-bounds headers unknown method/size mismatch cannot succeed. CRC/header disagreement and panic before method gate remain allowed observations.
reverse_reconstruction
Returned bytes admit any stored payload or deflate stream yielding them with central size=len; ignored CRC/header/suffix free. Missing-name error fiber=all lists without equal lossy name.
lookup_priority
First duplicate error never falls through to next.
byte_offsets
u16 local lengths,u32 central offsets/sizes castusize, unchecked arithmetic.
decode_order
Raw slice before method; unknown method cannot protect bad ranges.
allocation
Stored copies, deflate reserves size and can grow before final size rejection.
tests
Evidence boundary
Tiny stored archive open/name/read, absent, method99 and encryption tested. Deflate/size mismatch/malformed offsets/FrameNet file unexecuted.
Parent tests.md names actual selected tests; this scope does not claim all its branches executed. The compiled control listed in parent receipt applies only to the named mutated boundary.
This page in Markdown → https://md.groupants.elamur.ai/free/en/mova/onto/src/zip.rs.groupant/entry-read.groupant/