feat: BF16ThinkingEngine — distance table at source weight precision#125
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bf16_engine.rs (8 tests):
BF16 distance table (u16 bit patterns, NOT integers)
bf16_to_f32 lossless (bit shift), sign bit = gate decision
cycle(): F32x16 SIMD with BF16→f32 conversion per lane
cycle_with_temperature(): softmax/T after BF16 accumulation
from_codebook(): build from ClamCodebook pairwise StackedN cosine
from_f32_cosines(), from_f64_cosines(): build from raw cosines
load()/save(): 256×256 × 2 bytes = 128 KB files
Tests verify:
- Real negative values in BF16 table (not CDF rank relabeling)
- Inhibition from negative BF16 entries
- Temperature differentiates (low T = fewer active, high T = more)
- Different inputs produce different peaks
- BF16 roundtrip error < 0.01 (1 ULP)
builder.rs:
TableType::BF16 added
BuiltEngine::BF16(BF16ThinkingEngine) with all match arms
Temporary u8→BF16 conversion path until BF16 lenses are baked
252 tests pass (+8 new).
https://claude.ai/code/session_019RzHP8tpJu55ESTxhfUy1A
AdaWorldAPI
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Apr 17, 2026
…eam #150 ## Stale artifact removal (182 files, 3 MB) `AdaWorldAPI-lance-graph-d9df43b/` was a committed snapshot of an older upstream version (48 .rs files vs our 98). Full audit confirmed: - ZERO files exist only in the artifact (every file has a counterpart) - Every differing file: ours >= artifact in LOC (ours is strictly ahead) - All upstream features (#125 parameter_substitution, #140 lance_vector_search) are already in our src tree The directory created GitHub path confusion — duplicate navigation paths for datafusion_planner, spo, blasgraph, neighborhood, arigraph. Removing it eliminates that confusion with zero content loss. ## Cherry-pick: spark_dialect.rs from upstream PR #150 The ONE file upstream has that we didn't: - `crates/lance-graph/src/spark_dialect.rs` (107 LOC) Spark SQL dialect for DataFusion unparser: backtick quoting, STRING type casting, EXTRACT for dates, BIGINT/INT types, LENGTH(), derived table aliases. - `crates/lance-graph/tests/test_to_spark_sql.rs` (293 LOC) Full test suite for Spark SQL output. - `pub mod spark_dialect;` added to lib.rs Adapted from upstream's DF 50.3 to our DF 51 — same API surface, no changes needed. ## Upstream audit result (for the record) Upstream (lance-format/lance-graph) is at v0.5.4. Our fork is at v0.5.3 with newer deps (arrow 57 vs 56.2, datafusion 51 vs 50.3). Other than spark_dialect, every upstream feature and fix is already present in our source tree — parameter_substitution (#125), lance_vector_search (#140), complex RETURN clauses (#142), duplicate columns fix (#128) are all in `crates/lance-graph/src/`. Their deleted `simple_executor` was a prototype cold-path executor we never had. Our `ExecutionStrategy::DataFusion` path (6K LOC planner) + `ExecutionStrategy::BlasGraph` (semiring algebra) subsume it. The user has flagged adding a deliberate `ExecutionStrategy::Simple` cold path as a 4th strategy for trivial queries — that's a separate PR per the documented matrix of execution strategies. https://claude.ai/code/session_01NYGrxVopyszZYgLBxe4hgj
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bf16_engine.rs (8 tests):
BF16 distance table (u16 bit patterns, NOT integers)
bf16_to_f32 lossless (bit shift), sign bit = gate decision
cycle(): F32x16 SIMD with BF16→f32 conversion per lane
cycle_with_temperature(): softmax/T after BF16 accumulation
from_codebook(): build from ClamCodebook pairwise StackedN cosine
from_f32_cosines(), from_f64_cosines(): build from raw cosines
load()/save(): 256×256 × 2 bytes = 128 KB files
Tests verify:
- Real negative values in BF16 table (not CDF rank relabeling)
- Inhibition from negative BF16 entries
- Temperature differentiates (low T = fewer active, high T = more)
- Different inputs produce different peaks
- BF16 roundtrip error < 0.01 (1 ULP)
builder.rs:
TableType::BF16 added
BuiltEngine::BF16(BF16ThinkingEngine) with all match arms
Temporary u8→BF16 conversion path until BF16 lenses are baked
252 tests pass (+8 new).
https://claude.ai/code/session_019RzHP8tpJu55ESTxhfUy1A