Function compile_vector_search 

pub fn compile_vector_search(
    ast: &QueryAst,
) -> Result<CompiledVectorSearch, CompileError>

Compile a QueryAst into a CompiledVectorSearch describing a vector-only retrieval execution.

Mirrors compile_search structurally. The AST must contain exactly one QueryStep::VectorSearch step; filters following the search step are partitioned by partition_search_filters into fusable and residual sets. Unlike compile_search this path does not produce a TextQuery; the caller’s raw query string is preserved verbatim for the coordinator to bind to embedding MATCH ?.

Errors

Returns CompileError::MissingVectorSearchStep if the AST contains no QueryStep::VectorSearch step.