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https://github.com/allaunthefox/SilverSight.git
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allaun
3504bca392
Implements the YaFF-inspired separation of schema, layout, and access pattern
in Core/SilverSight/Semantics/:
- Schema.lean: fixed-size Schema typeclass with byteSize and wellFormed.
- Layout.lean: Layout enum, AccessProfile cost model, and cost-based selector
with an ε-suboptimality theorem.
- WireFormat.lean: certified encode/decode/roundTrip/encode_size structure.
- View.lean: zero-copy View with address-arithmetic invariant.
- LayoutBridge.lean: certified layout-conversion structure and identity bridges.
- CanalLayout.lean: CanalRegime enum and regime-aware layout selection.
Also updates:
- lakefile.lean: adds SilverSight.Semantics.* roots to SilverSightCore.
- docs/ARCHITECTURE.md, RRC_REFACTOR_READINESS.md, PROJECT_MAP.{md,json},
build_logs/2026-06-21_session_build_baseline.md, and GLOSSARY.md.
- AGENTS.md: build baseline, blessed surfaces, and pending proof work.
Build: 2987 jobs, 0 errors (lake build)
Tests: Python 21/21, Lean/C 35/35
48 lines
1.4 KiB
Text
48 lines
1.4 KiB
Text
/-
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SilverSight.Semantics.View
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A View is a structured value read from a byte range without copying the
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underlying buffer. The Core defines the address-arithmetic contract; the
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zero-copy property is a theorem about offsets and schema sizes.
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Only fixed-size Core schemas have built-in accessors. Variable-length views
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are a library extension that must preserve the same address-arithmetic
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invariant.
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-/
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import SilverSight.Semantics.Schema
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namespace SilverSight.Semantics
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/-- A zero-copy view of a fixed-size schema value inside a byte buffer.
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`valid` is the address-arithmetic invariant: the schema's byte range
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fits entirely inside the buffer starting at `offset`. -/
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structure View (α : Type) [Schema α] where
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base : ByteArray
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offset : Nat
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valid : offset + byteSize α ≤ base.size
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namespace View
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/-- Read a UInt8 through a one-byte view. The result is the byte at the
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view's offset; no copy of the underlying buffer occurs. -/
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def readUInt8 (v : View UInt8) : UInt8 :=
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v.base.get v.offset (by
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have h : byteSize UInt8 = 1 := rfl
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have hv := v.valid
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omega
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)
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/-- Reading a UInt8 view returns exactly the byte at the stored offset. -/
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@[simp]
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theorem readUInt8_eq_get (v : View UInt8) :
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readUInt8 v = v.base.get v.offset (by
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have h : byteSize UInt8 = 1 := rfl
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have hv := v.valid
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omega
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) := rfl
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end View
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end SilverSight.Semantics
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