stack-encrypt: ordering operators Lt, Lte, Gt, Gte and Between, and remove QueryUsing::index #1186

Background

ADR-0009 decisions 1 and 7 add the ordering operators Lt, Lte, Gt, Gte and Between. Between is one query term carrying both ORE left ciphertexts, inclusive at both ends, bound in SQL as col BETWEEN $1 AND $2.

Problem

stack-encrypt queries ORE and OPE only by naming the index (.index(Ore)), and an ORE query term today is the whole CLLW ciphertext rather than the left half. EQL v4 stores block ORE terms, which the engine does not derive yet (#1140).

Proposal

• The operator types Lt, Lte, Gt, Gte and Between, with Supports on the ORE and OPE indexes for the integer types they order.
• Between as one term exposing its two bounds, refusing lo > hi.
• Remove QueryUsing::index(..), now that every index a plan can declare is reachable through an operator.
• ADR-0009's code matches what this ships.

Blocked by

• stack-encrypt: delete dynamic::Value and Scalar, derive terms through vitaminc, add block ORE, drop Bool order terms #1140: block ORE through vitaminc, which gives the left-ciphertext query term.

Related

• stack-encrypt: name the operator, not the index, in a query (Eq and Matches) #1182: the operator-typed query.
• Tracking: implement ADR-0009, operator-typed query terms for Stack Encrypt #1178: tracks ADR-0009.