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A try that is the last statement of a function now emits as a statement whose branches return their values, instead of an arrow IIFE created and called on every invocation. The value form keeps its wrapper for true expression positions such as `x = try ...`, where there is no function to return from. Values are identical: the wrapper only turned each branch's last expression into a return, and the statement form does the same in place. `this` and `arguments` were already preserved by the arrow. An async tail try loses the async wrapper and its extra await; a generator may now yield inside a tail try, which the wrapper rejected. Of 130 tail-position tries across packages and src, every one now emits in place; the 28 wrappers that remain are assignments. Corpus: lowerings.js changes one site, three lines, from the wrapper to the statement; 184 artifacts unchanged. The parser is untouched. The browser bundle is regenerated under the pinned Bun. Battery: twelve rows in errors.rip pin the body and handler values, the handler-less form, finally ordering, an explicit inner return, a catch pattern, a try after other statements, yield and await inside, and the emitted code for the tail, async and value forms. Two sweep rows that pinned the wrapper shape now pin the statement.
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Summary
A
trythat is the last statement of a function now emits as a statement whose branchesreturntheir values. It used to be wrapped in an arrow IIFE, created and called on every invocation:The value form keeps its wrapper in true expression positions such as
x = try ..., where there is no function to return from.Same values. The wrapper only turned each branch's last expression into a
return; the statement form does that in place.thisandargumentswere already preserved by the arrow.finallyruns after the return either way.Two things improve. An async tail
trydrops the async wrapper and the extraawaitaround it. A generator may nowyieldinside a tailtry, which the wrapper rejected.Reach. 130 tail-position tries across
packagesandsrcnow emit in place, 27 of them in the sites manager. The 28 wrappers that remain are all assignments.Artifacts.
lowerings.jschanges one site, three lines; 184 corpus artifacts unchanged; parser untouched; browser bundle regenerated under Bun 1.4.0.Test
Twelve new rows in
errors.rip; twosweep.riprows that pinned the wrapper now pin the statement. Language battery 3270 passing, toolchain gates 661 passing, fulltest:allsuite green across all 26 lanes.