tests/language/flowcontrol/generators_loop_condition.bas

10 REM A WHILE or UNTIL on the LOOP composes with DO EACH: it is checked
20 REM after each trip through the body, with the loop variable still
30 REM holding that trip's value. Stopping abandons the generator cleanly.
40 GEN COUNTUP(N#)
50     FOR I# = 1 TO N#
60         EMIT I#
70     NEXT I#
80 END GEN
90 DO EACH V# IN COUNTUP(10)
100     PRINT V#
110 LOOP UNTIL V# = 3
120 DO EACH W# IN COUNTUP(4)
130     PRINT W# * 10
140 LOOP WHILE W# < 3
150 PRINT "DONE"
Fix generator teardown leaks, add RETURN-in-GEN and LOOP conditions on DO EACH Review findings and follow-ups from PR #61 review: - runtime_generator.c: akbasic_runtime_release_generator() now releases the forGeneratorEnv of every scope it walks through. Abandoning a generator that was itself suspended inside a FOR EACH over another generator stranded the inner generator's pool slot; a loop doing so exhausted the twelve-slot pool and died far from the cause. - runtime.c/runtime.h: new akbasic_runtime_unwind_to_environment(), the shared teardown for the error unwinds in pump_generator() and call_function() -- both previously bare prev_environment() loops with the same suspended-generator blindness. - runtime_commands.c: bare RETURN standing in a GEN's own frame ends the generator exactly as END GEN does -- a GEN is a function at heart. RETURN with a value there is refused (values leave a GEN only through EMIT). The no-frame error message now says "GOSUB, DEF, or GEN". - runtime_structure.c: LOOP WHILE/UNTIL composes with DO EACH -- checked after each trip with the loop variable still holding that trip's value; a condition that stops the loop abandons the generator exactly as EXIT does. Previously the condition was silently ignored, while the verb reference documented it as working. - parser_commands.c: trailing tokens after the generator call on a FOR EACH/DO EACH line are refused at parse. Previously they sat unparsed and blew up only after the loop completed, when the parent scope resumed the line mid-statement -- an error at the loop's end pointing at its start. - tests/generators.c: pool-exhaustion tests for the nested-abandonment and LOOP-condition paths, RETURN semantics tests, and a direct test of the unwind primitive. Three new golden pairs cover RETURN, LOOP conditions and the misplaced-condition parse error. - docs: RETURN and LOOP-condition semantics in 04-control-flow.md and 11-verb-reference.md; corrected the self-recursion analogy (functions are re-entrant here). TODO.md 1.10 records the generator design decisions the code comments were already citing, plus the zero-arg parameter-list limitation. MAINTENANCE.md gains the abandoned-generators invariant those comments also cited. Co-Authored-By: Andrew Kesterson <andrew@aklabs.net> Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> 2026-08-06 11:29:17 -04:00			`10 REM A WHILE or UNTIL on the LOOP composes with DO EACH: it is checked`
			`20 REM after each trip through the body, with the loop variable still`
			`30 REM holding that trip's value. Stopping abandons the generator cleanly.`
			`40 GEN COUNTUP(N#)`
			`50 FOR I# = 1 TO N#`
			`60 EMIT I#`
			`70 NEXT I#`
			`80 END GEN`
			`90 DO EACH V# IN COUNTUP(10)`
			`100 PRINT V#`
			`110 LOOP UNTIL V# = 3`
			`120 DO EACH W# IN COUNTUP(4)`
			`130 PRINT W# * 10`
			`140 LOOP WHILE W# < 3`
			`150 PRINT "DONE"`