ADR-132: A named path pattern may render a page of its matches

Context

ADR-129 gave patterns one consumer, a chain, which needs a pattern from its own scheme back to it and shows matches only as steps. Most of what a record asks has no such shape: a thesis nothing objects to (one node with WHERE NOT), an argument an Active claim undercuts (across schemes), a step the record calls unfinished. A view template (ADR-130) can already list them with match(name), and report: true (ADR-131) makes them findings. The question is who writes the list’s template.

Decision

A pattern table may take output: and title:, and the page is a view luria supplies.

patterns:
  unopposed:
    match: >-
      (c:CLAIM {role: 'thesis'}) WHERE NOT (c)<-[:objects_to]-(:CLAIM)
    blurb: Theses nothing in the record has objected to yet.
    output: docs/unopposed.md

• One template, shipped. At load, a pattern with an output adds a view on luria:pattern.md.j2 (luria/view_templates/), with the pattern’s name, source, blurb, title and named nodes as its values. The view loader tries the luria: prefix in the package before the project root, inside the same sandbox. The template writes codes bare, and the link fixer links them in the page’s frame.
• The page. A heading (the title, else the name), the blurb, the pattern in a code span with its count, and a table: one column per named node, headed var (LABEL) in pattern order; one row per match, sorted by its codes; each cell the code and ” — ” title, | escaped by a cell filter. “No matches.” replaces an empty table. An anonymous node is not a column, so two matches differing only in one are a single row; match now collapses them for every template. A pattern that names no node, or a title without an output, is refused at load.
• Being a view, it is written by luria index, held fresh by --check, kept out of the reference scan, and located on error as patterns.<name> with the template line, which its stamp names too.
• A list, never a finding. No lint class reads the page; whether a match matters is a judgement (ADR-035). report: true is the consumer that makes matches findings, and a pattern may have both. A pattern-ok: acknowledgement silences the finding and leaves the row: the page lists what matches, not what is outstanding.
• One collision check for every renderer. At load, every path luria renders is gathered: scheme outputs and indexes, the status reports (reports.NAMES, which the renderer reads too), the record description, the configuration reference, chains, views and pattern pages. Two that coincide are refused, naming both. Before, no pair was checked, and whichever view wins looks correct.

Alternatives considered

• A renderer of its own, with a pattern_match/2 predicate, a tuple reader in the logic core and a module writing the table. This was the first version of this decision. It duplicated match and needed its own freshness, exclusion and error locating, which a view already has.
• Close #373 as served by views, each record writing its own template. Nothing new in luria, but every record rewrites the same twenty-line table and the copies drift: one escapes |, another forgets the empty case.
• A reports: family that names patterns: another family for what one key does, where output: already means “renders a page here” on a chain.
• Fixed placement under docs/reports/, which holds luria’s own reports; a record’s questions belong in its own docs.
• Grouping rows under their first column. Deferred until needed.

Consequences

• View gains a context and an origin; luria views lists a pattern page as patterns.<name>. A page must be listed in docs/README.md like any other page there (check_docs_index).
• Tried on nucleation (scratch copy of cf318d525, network off). With no output, luria index writes the same files and luria lint prints the same lines as luria main, its report: true and chain patterns included. With unopposed and undercut: (g:ARG)<-[:undercuts]-(c:CLAIM {status: 'Active'}) added, 286 of 361 theses are unopposed and 8 rows cover 6 undercut arguments, the same sets a script reading the frontmatter found. The status reports did not change, and the lint added only the docs-index entries for the two pages.
• examples/argument-map declares unfinished; its one row is INF-004.