v2.2.0

Added

• machines/sinq.shoddy
  — Shoddy INtegrated Query: the half of a query the rest of the library could
  not say, which is the word by. Ordering by a key and by several keys
  (OrderBy, OrderByDesc, OrderWith, ByKey, ThenBy, Descending),
  grouping (GroupBy), joining (JoinOn, GroupJoinOn), the set words
  (Distinct, DistinctBy, Union, Intersect, Except), walking a record
  type that holds itself (Descendants, Offspring, SelectMany), the
  extremes by a key (MinBy, MaxBy, and their Opt twins), and the total
  twins that answer an Option instead of aborting (FirstOpt, LastOpt,
  SingleOpt, FindOpt). It re-declares nothing: Map, Filter, Fold and
  Sort are still builtins and Sum is still stats'.
• Sorting by a key at last. Sort is a builtin, ascending-only, and takes
  no selector — handed records it stops the program with
  SORT expects all NUMBERs or all STRINGs. OrderByDesc(staff, Pay) is now
  an ordinary line. The sort is a stable merge sort, so equal keys keep source
  order and ThenBy means what it says.
• No adapter for arrays, vectors or matrices, because none is needed. A
  Matrix's Cells is already an array and an array is already a sequence, so
  a matrix is queried through the same words as a list.
• seed-sinq puts thirteen of them at the reckoner keyboard in halifax and
  sparky alike — SORTBY, SORTBYDESC, GROUPBY, MINBY, MAXBY,
  FINDFIRST, TAKEWHILE, SKIPWHILE, DISTINCT, UNION, INTERSECT,
  EXCEPT and CHUNK. The eight that take a selector take a quoted program:
  { 1 2 3 4 } [ 2 MOD ] SORTBY.
• A worked example that the gate runs. tst/sinq-demo.shoddy queries a
  customer/order graph, a catalogue, a self-holding org tree and a matrix in
  one program, and is reproduced line for line on the machine's page — so the
  page cannot show code that no longer compiles.

Changed

• Five machines dropped code they should never have had to write. alg's
  hand-rolled insertion sort is gone and its canonicalisation is n log n;
  json and xml both carried a written apology that Sort would not sort a
  list of pairs, and both are gone with the per-key re-lookups they forced;
  reckoner's WORDS is a GroupBy where it was three Defs; bool's
  Quine–McCluskey dedupes with Distinct and scores each implicant once
  instead of twice.
• seq's documented cost model was wrong, and is corrected everywhere. A
  Shoddy list is contiguous underneath, so Rest hands back a copy of the
  tail and a First/Rest walk is quadratic — 74 ms at 12,500 elements and
  3,585 ms at 50,000. Lists are not cons cells. The machine header, the
  seq page and both
  AI grounding pages said otherwise and now say this.
• Only self-tail-recursion becomes a loop, which is now written down
  where it can be found. Mutual recursion costs a frame per element like any
  other call, and the ceiling is about 20,000 frames — a hard process kill with
  no line number. sinq's own suite runs fifty thousand elements for exactly
  this reason; it is the only suite in the tree big enough to catch either
  fault.