Semantic Diff

#8636 Developer playground: compare Lambda before and after optimization

3 commits, rendered from their records.

Summary

Range	Commits	Changelog	Areas	JS output changes	Formats	Failed checks
`58f1bd223b455d60990dbce94b77720644f98bf9..pr-8636`	3	🏠 Internal		0	none	5

Changelog draft

🏠 Internal

Add before/after optimization views and inline diffs to the developer playground's Lambda tab, with optimized Lambda output in playground API v9. #8636

Files changed by more than one commit

`CHANGELOG.md`	`f7d55d473`, `0dbdd015b`
`packages/dev-playground/package.json`	`f7d55d473`, `e33b9658b`
`packages/dev-playground/scripts/lambda-diff.test.mjs`	`f7d55d473`, `e33b9658b`
`packages/dev-playground/src/LambdaDiff.res`	`f7d55d473`, `e33b9658b`
`packages/dev-playground/src/LambdaInlineDiff.res`	`f7d55d473`, `e33b9658b`
`packages/dev-playground/src/LambdaView.res`	`f7d55d473`, `e33b9658b`
`packages/dev-playground/src/Main.res`	`f7d55d473`, `e33b9658b`

`58f1bd223b455d60990dbce94b77720644f98bf9..pr-8636`

f7d55d473 · Florian Hammerschmidt · Sep 09, 2026

Developer playground: Add lambda views before and after optimisation, including diffs

Edits CHANGELOG.md; a changes/ fragment carries the entry outside release PRs
No Tests trailer

15 files · +929 −19 · changelog 1 · lambda 2 · compiler 1 · playground 10 · other 1

M	`CHANGELOG.md`	+1	−0
M	`compiler/core/lam_compile_main.ml`	+5	−1
M	`compiler/core/lam_compile_main.mli`	+4	−0
M	`compiler/jsoo/jsoo_playground_main.ml`	+22	−3
M	`packages/dev-playground/package.json`	+1	−1
A	`packages/dev-playground/scripts/lambda-diff.test.mjs`	+241	−0
M	`packages/dev-playground/src/Bindings.res`	+1	−0
M	`packages/dev-playground/src/CompilerApi.res`	+13	−1
M	`packages/dev-playground/src/CompilerApi.resi`	+1	−0
A	`packages/dev-playground/src/LambdaDiff.res`	+161	−0
A	`packages/dev-playground/src/LambdaInlineDiff.res`	+220	−0
A	`packages/dev-playground/src/LambdaView.res`	+116	−0
M	`packages/dev-playground/src/Main.res`	+22	−13
M	`packages/dev-playground/src/styles.css`	+100	−0
M	`packages/playground/playground_test.cjs`	+21	−0

0dbdd015b · Florian Hammerschmidt · Sep 09, 2026

Changelog

🏠 Internal

🏠 InternalAdd before/after optimization views and inline diffs to the developer playground's Lambda tab, with optimized Lambda output in playground API v9. #8636

Changelog fragment changes/developer-playground-lambda-diff.internal.md
Edits CHANGELOG.md; a changes/ fragment carries the entry outside release PRs
No Tests trailer

2 files · +1 −1 · changelog 2

M	`CHANGELOG.md`	+0	−1
A	`changes/developer-playground-lambda-diff.internal.md`	+1	−0

e33b9658b · Florian Hammerschmidt · Oct 14, 2026

Cache playground Lambda diffs and bound token work by block

Keep the Lambda view mounted, cache its rendered comparison by input text, and render collapsed context only when expanded. Preserve expansion for unchanged regions across edits.

Count shared edges once in the line budget, prioritize atoms in token alignment, and admit whole changed blocks before charging the shared token budget. Cover the algorithm and rendering regressions, and document the API v9 capture boundary.

No Tests trailer

8 files · +296 −69 · docs 1 · playground 7

M	`CONTRIBUTING.md`	+12	−0
M	`packages/dev-playground/package.json`	+1	−1
M	`packages/dev-playground/scripts/lambda-diff.test.mjs`	+129	−1
A	`packages/dev-playground/scripts/runtime-loader.mjs`	+10	−0
M	`packages/dev-playground/src/LambdaDiff.res`	+11	−3
M	`packages/dev-playground/src/LambdaInlineDiff.res`	+20	−11
M	`packages/dev-playground/src/LambdaView.res`	+93	−36
M	`packages/dev-playground/src/Main.res`	+20	−17