steve-downey / compile-time-scheme / 30236977465

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github

Committed by steve-downey

Commit Message

Merge step L21: sender backend for the CL core (Track A)

The Common Lisp core evaluated over Beman Execution senders, making decision
D5's thesis structural rather than aspirational.

The closure backends multiplex four things onto one result<value> wire -- a
value, a diagnosed error, a return-from unwind and a throw unwind -- and tell
them apart with sentinel parse_error messages compared by pointer identity. A
sender has three channels natively, so the sentinels are deleted rather than
ported: value to set_value, diagnosed error to set_error, unwind in flight to
set_stopped. Nothing is multiplexed, so nothing needs discriminating.

unwind-protect becomes an ordinary sender adapter whose three completion
functions all funnel into one cleanup call, which is what makes "cleanup runs
on every exit path" a structural property here instead of a checklist item.

Parity covers L11-L16, one step past the L15 the plan asked for: all 68 runtime
cases transcribe cps_code.test.cpp / eval_direct.test.cpp sources verbatim, so
the claim is diffable. DIV-0015 records that the sender backend can only offer
runtime evidence, DIV-0016 the mendler_para bridge for foundation::fix, DIV-0017
the L20 gap that L20 itself will revisit.

754 tests pass; lint clean; frozen smdscheme tree untouched.

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1467 of 1540 new or added lines in 17 files covered. (95.26%)

3 existing lines in 1 file now uncovered.

10363 of 11278 relevant lines covered (91.89%)

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