domain-table-shard

Local, deterministic structural decomposition of GFM markdown tables: parses header/separator/data rows, infers a per-column type, and emits an opaque shard of structural facts (row count, column count, per-column type, null/distinct counts, numeric summary stats) -- the real cell values never appear in the emitted shard, only their shape. Column headers are treated as schema, not content, and pass through as-is. Same document-structural-decomposition gap as domain-transcript-shard (ADR 0035), applied to tabular data instead of speaker-turn dialogue. Pure logic, zero I/O beyond reading the input file, zero AI calls.

What it is for

Local, deterministic structural decomposition of GFM markdown tables: find table blocks, parse header/separator/data rows, and reduce each column to structural facts -- type, null/distinct counts, numeric summary stats -- without ever retaining a real cell value past build_shard. Column headers are schema, not content, and pass through as-is; cell values never appear in the emitted DocumentShard.

Same "document structural decomposition" gap as domain-transcript-shard (ADR 0035), applied to tabular data instead of speaker-turn dialogue. Nothing here calls an AI or makes a network request.

Table detection is delegated to pulldown-cmark's GFM-tables extension rather than hand-rolled line parsing -- a real, widely-used markdown parser handles escaped pipes, inline formatting inside cells, and malformed/short rows correctly; a hand-rolled split('|') scanner does not, and silently mis-parsing a legal fact-pattern table is a worse failure than a build dependency.

Capabilities

crate root

Local, deterministic structural decomposition of GFM markdown tables:

ColumnShard

Local, deterministic structural decomposition of GFM markdown tables:

ColumnType

Local, deterministic structural decomposition of GFM markdown tables:

DocumentShard

Local, deterministic structural decomposition of GFM markdown tables:

NumericSummary

Local, deterministic structural decomposition of GFM markdown tables:

Table

Local, deterministic structural decomposition of GFM markdown tables:

TableShard

Local, deterministic structural decomposition of GFM markdown tables:

How to use it

No examples/ target and no doctest in this crate's rustdoc. The tests listed under Verification are the closest executable usage.

Module structure

No public modules: the crate root is its whole surface.

Public surface

`crate root`

No pub use re-exports: every item above is declared in this crate.

Boundary

Depends on no other workspace tier.

Shares tier domain with 41 other crates: domain-agreements, domain-ai-report, domain-billing, domain-catalog, domain-classify, domain-comments, domain-competitive-intel, domain-contact, … (41 total).

_What this crate deliberately does NOT own is a judgment. No committed registry records one for it, so none is stated here._

Where it sits

Dependencies

Runtime, from outside the workspace.

Development, in this workspace.

Build. None.

Depended on by. 3 workspace crates.

Signal flow — what reaches this crate, and what it reaches.

flowchart LR
  n_tools_doc_ask["tools-doc-ask"] -->|uses| SELF
  n_tools_doc_shape["tools-doc-shape"] -->|uses| SELF
  n_tools_knowitall["tools-knowitall"] -->|uses| SELF
  SELF["domain-table-shard"]
  SELF -->|development| n_tools_cli_conformance["tools-cli-conformance"]
  classDef self fill:#1f883d,stroke:#1f883d,color:#fff;
  class SELF self;

Feature flags

No Cargo features are defined: every capability is unconditional, so no consumer can receive a half-wired crate.

Targets

Error model

No public error type was detected: no public item declares a type named *Error, and no public signature returns one.

Operational characteristics

No unsafe block, unsafe fn, unsafe impl or unsafe trait was found by the parser anywhere in this crate's source.

Configuration

No environment variable is read with a literal name anywhere in this crate. A variable whose key is computed at run time cannot be listed here, and is not claimed to be absent.

Related capabilities

3 workspace crates depend on this one: tools-doc-ask, tools-doc-shape, tools-knowitall.

Verification

Evidence by module. How often each public module is named by something executable.

What the tests establish, by name:

• build_shard_never_leaks_a_real_text_cell_value — src/lib.rs
• build_shard_reports_correct_shape_for_both_tables — src/lib.rs
• classify_column_detects_numeric_with_correct_summary — src/lib.rs
• classify_column_detects_text_and_counts_nulls_and_distinct — src/lib.rs
• classify_column_does_not_panic_on_the_literal_string_nan — src/lib.rs
• classify_column_even_count_median_averages_the_two_middle_values — src/lib.rs
• classify_column_treats_a_mixed_column_as_text_not_numeric — src/lib.rs
• parse_tables_finds_both_blocks_and_ignores_surrounding_prose — src/lib.rs
• parse_tables_handles_aligned_separator_rows — src/lib.rs
• parse_tables_handles_an_escaped_pipe_inside_a_cell — src/lib.rs
• parse_tables_pads_a_short_row_with_empty_cells_per_gfm_spec — src/lib.rs
• cli_definition_conforms — src/main.rs

Documentation coverage

pie showData
    title Public items with rustdoc
    "Documented" : 9
    "No rustdoc detected" : 0

Metrics

pie showData
    title Public API by kind
    "enum" : 1
    "function" : 3
    "struct" : 5

pie showData
    title Rust source composition
    "Code" : 336
    "Blank or comment" : 132

Generation

Rendered by tools-corpus corpus readme from repository evidence alone, renderer schema 2, lexicon current. No model, network service or database was consulted. Regenerate with tools-corpus corpus readme --write; verify with --check.