shoney.arickathil
8817fdec2a
- `backlink C.f` field type: parsed, typed as `multi C`, and VIRTUAL — filtered out of the stored row layout (no column, omittable in ctor/insert), collected in clsrec.cr_backlinks - reading a backlink (`d.staff`) lowers to DB_PROBE on the source class's index for the backing column (backlink_target resolves the (source class, index number); a backlink with no backing index has no efficient read) - `ref C` navigation (`e.dept.name`) chains: a ref value is the target row's id, so a `Ref C` base navigates into C's fields exactly like a table-class value, routing to DB_GET_FIELD both in typecheck and emit - query navigation source `from s in d.staff`: emit_query evaluates the nav expr to get its id-list instead of DB_SCAN; QNav typechecks with the range var bound to the navigation's element class - fixture run/db-query-relations proves both directions; oop-e2e 75/0, woc-test 566/0, log-watcher 7/0 - still ahead for employee: order/take, group-by aggregates, projection records, delete + update-through-row Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
30 lines
875 B
Text
30 lines
875 B
Text
-- iteration 9b: ref + backlink navigation. `e.dept.name` chains a ref to
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-- its target row (a point read); `d.staff` reads a backlink by probing the
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-- source class's index — both execute in the engine, no join written.
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@table(name: "dept", index: [name])
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class Dept {
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name: Text
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staff: backlink Emp.dept
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}
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@table(name: "emp", index: [dept])
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class Emp {
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name: Text
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dept: ref Dept
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}
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fn main() {
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let eng = insert Dept { name: "eng" }
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let ops = insert Dept { name: "ops" }
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insert Emp { name: "asha", dept: eng }
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insert Emp { name: "bram", dept: eng }
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insert Emp { name: "dora", dept: ops }
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print("-- forward (e.dept.name):")
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for e in from x in Emp select x {
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print(e.dept.name)
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}
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print("-- backward (d.staff):")
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for d in from x in Dept where x.name == "eng" select x {
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for s in from y in d.staff select y {
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print(s.name)
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}
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}
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}
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