Derive tuple labels for rest elements from array binding patterns by rbuckton · Pull Request #59045 · microsoft/TypeScript

Ron Buckton (rbuckton) · 2024-06-26T22:35:57Z

While working on #58243, a community member asked if we could label the tuple we use to properly type arguments to the next() methods of iterators and generators. A brief experiment showed that directly labeling the tuple element resulted in the creation of thousands of new types in some tests since iterator/generator instantiations would produce new named tuple elements since named tuple elements are cached far less frequently.

An alternative to that approach would be to use an additional source for the label when the label comes from a rest parameter whose name is actually an ArrayBindingPattern:

declarefunctiona(...args: []|[number]): void;a(1);// quickinfo shows `(args_0: number)`declarefunctionb(...[value] : []|[number]): void;b(1);// quickinfo now shows `(value: number)`// quickinfo previously showed `(__0_0: number)`

Since this is merely treated as an additional labeling source, there is no need to synthesize additional types for named tuple elements.

This also improves label inference in other cases such as elision and object assignment pattern elements:

declarefunctiona(...[x,,z]: [number,number,number]): void;a(1,2,3);// quickinfo shows `(x: number, arg_1: number, z: number)`// previously showed `(__0_0: number, __0_1: number, __0_2: number)`

Related #58243 (comment)

Fixes#56289
Closes#57619

Daniel Rosenwasser (DanielRosenwasser) · 2024-06-27T01:11:52Z

TypeScript Bot (@typescript-bot) test it

TypeScript Bot (typescript-bot) · 2024-06-27T01:11:56Z

Starting jobs; this comment will be updated as builds start and complete.

Command	Status	Results
`test top400`	✅ Started	✅ Results
`user test this`	✅ Started	✅ Results
`run dt`	✅ Started	✅ Results
`perf test this faster`	✅ Started	👀 Results

TypeScript Bot (typescript-bot) · 2024-06-27T01:33:35Z

Hey Daniel Rosenwasser (@DanielRosenwasser), the results of running the DT tests are ready.

Everything looks the same!

You can check the log here.

TypeScript Bot (typescript-bot) · 2024-06-27T01:38:39Z

Daniel Rosenwasser (@DanielRosenwasser) Here are the results of running the user tests with tsc comparing main and refs/pull/59045/merge:

Everything looks good!

TypeScript Bot (typescript-bot) · 2024-06-27T01:47:33Z

Daniel Rosenwasser (@DanielRosenwasser)
The results of the perf run you requested are in!

Here they are:

tsc

Comparison Report - baseline..pr

_Metric	_baseline	_pr	_Delta	_Best	_Worst	_p-value
_{Compiler-Unions - node (v18.15.0, x64)}
_Errors	₃₀	₃₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_62,153	_62,153	_~	_~	_~	_{p=1.000 n=6}
_Types	_50,242	_50,242	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{192,789k (± 0.75%)}	_{192,789k (± 0.73%)}	_~	_192,133k	_195,637k	_{p=0.575 n=6}
_{Parse Time}	_{1.31s (± 0.57%)}	_{1.30s (± 1.05%)}	_~	_1.28s	_1.32s	_{p=0.273 n=6}
_{Bind Time}	_0.71s	_0.71s	_~	_~	_~	_{p=1.000 n=6}
_{Check Time}	_{9.44s (± 0.38%)}	_{9.44s (± 0.69%)}	_~	_9.38s	_9.55s	_{p=0.936 n=6}
_{Emit Time}	_{2.75s (± 0.83%)}	_{2.74s (± 1.37%)}	_~	_2.67s	_2.78s	_{p=1.000 n=6}
_{Total Time}	_{14.21s (± 0.30%)}	_{14.20s (± 0.24%)}	_~	_14.17s	_14.25s	_{p=0.744 n=6}
_{angular-1 - node (v18.15.0, x64)}
_Errors	₅	₅	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_944,114	_944,114	_~	_~	_~	_{p=1.000 n=6}
_Types	_407,050	_407,050	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{1,218,382k (± 0.00%)}	_{1,218,347k (± 0.00%)}	_~	_1,218,275k	_1,218,373k	_{p=0.335 n=6}
_{Parse Time}	_{6.67s (± 0.74%)}	_{6.66s (± 0.92%)}	_~	_6.59s	_6.76s	_{p=0.809 n=6}
_{Bind Time}	_{1.87s (± 0.55%)}	_{1.87s (± 0.56%)}	_~	_1.85s	_1.88s	_{p=0.801 n=6}
_{Check Time}	_{30.64s (± 0.19%)}	_{30.72s (± 0.29%)}	_~	_30.59s	_30.81s	_{p=0.148 n=6}
_{Emit Time}	_{13.54s (± 0.68%)}	_{13.57s (± 0.31%)}	_~	_13.52s	_13.62s	_{p=1.000 n=6}
_{Total Time}	_{52.72s (± 0.16%)}	_{52.81s (± 0.23%)}	_~	_52.65s	_52.97s	_{p=0.229 n=6}
_{mui-docs - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_2,132,386	_2,132,386	_~	_~	_~	_{p=1.000 n=6}
_Types	_926,170	_926,170	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{2,114,738k (± 0.01%)}	_{2,114,843k (± 0.01%)}	_~	_2,114,648k	_2,115,034k	_{p=0.173 n=6}
_{Parse Time}	_{9.72s (± 0.25%)}	_{9.73s (± 0.31%)}	_~	_9.70s	_9.78s	_{p=0.685 n=6}
_{Bind Time}	_{3.40s (± 0.69%)}	_{3.39s (± 0.94%)}	_~	_3.34s	_3.43s	_{p=0.683 n=6}
_{Check Time}	_{103.00s (± 0.57%)}	_{102.02s (± 1.35%)}	_~	_99.52s	_103.17s	_{p=0.173 n=6}
_{Emit Time}	_{0.19s (± 2.13%)}	_{0.19s (± 2.67%)}	_~	_0.19s	_0.20s	_{p=0.595 n=6}
_{Total Time}	_{116.31s (± 0.50%)}	_{115.33s (± 1.18%)}	_~	_112.87s	_116.46s	_{p=0.173 n=6}
_{self-build-src - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,231,640	_1,231,657	_{+17 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_261,187	_261,211	_{+24 (+ 0.01%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{2,347,576k (± 0.04%)}	_{2,347,596k (± 0.03%)}	_~	_2,346,508k	_2,348,766k	_{p=1.000 n=6}
_{Parse Time}	_{5.06s (± 0.44%)}	_{5.05s (± 0.45%)}	_~	_5.03s	_5.09s	_{p=0.810 n=6}
_{Bind Time}	_{1.93s (± 0.79%)}	_{1.93s (± 0.42%)}	_~	_1.93s	_1.95s	_{p=0.209 n=6}
_{Check Time}	_{34.05s (± 0.22%)}	_{34.16s (± 0.49%)}	_~	_33.94s	_34.38s	_{p=0.230 n=6}
_{Emit Time}	_{2.76s (± 2.56%)}	_{2.73s (± 1.95%)}	_~	_2.67s	_2.81s	_{p=0.471 n=6}
_{Total Time}	_{43.82s (± 0.30%)}	_{43.90s (± 0.41%)}	_~	_43.72s	_44.16s	_{p=0.689 n=6}
_{self-build-src-public-api - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,231,640	_1,231,657	_{+17 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_261,187	_261,211	_{+24 (+ 0.01%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{2,424,424k (± 0.06%)}	_{2,423,830k (± 0.02%)}	_~	_2,423,060k	_2,424,766k	_{p=0.936 n=6}
_{Parse Time}	_{6.25s (± 0.61%)}	_{6.24s (± 1.16%)}	_~	_6.15s	_6.36s	_{p=0.630 n=6}
_{Bind Time}	_{2.05s (± 0.67%)}	_{2.04s (± 0.74%)}	_~	_2.01s	_2.05s	_{p=0.324 n=6}
_{Check Time}	_{40.40s (± 0.26%)}	_{40.51s (± 0.19%)}	_~	_40.40s	_40.61s	_{p=0.128 n=6}
_{Emit Time}	_{3.24s (± 2.66%)}	_{3.25s (± 2.35%)}	_~	_3.17s	_3.36s	_{p=0.873 n=6}
_{Total Time}	_{51.95s (± 0.34%)}	_{52.04s (± 0.31%)}	_~	_51.87s	_52.29s	_{p=0.422 n=6}
_{self-compiler - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_258,818	_258,835	_{+17 (+ 0.01%)}	_~	_~	_{p=0.001 n=6}
_Types	_104,842	_104,866	_{+24 (+ 0.02%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{428,204k (± 0.01%)}	_{428,303k (± 0.01%)}	_{+100k (+ 0.02%)}	_428,252k	_428,362k	_{p=0.008 n=6}
_{Parse Time}	_{3.31s (± 1.17%)}	_{3.33s (± 1.18%)}	_~	_3.30s	_3.41s	_{p=0.455 n=6}
_{Bind Time}	_{1.31s (± 1.64%)}	_{1.31s (± 1.31%)}	_~	_1.29s	_1.34s	_{p=1.000 n=6}
_{Check Time}	_{17.80s (± 0.26%)}	_{17.80s (± 0.37%)}	_~	_17.70s	_17.86s	_{p=0.872 n=6}
_{Emit Time}	_{1.36s (± 1.59%)}	_{1.38s (± 0.92%)}	_~	_1.36s	_1.39s	_{p=0.217 n=6}
_{Total Time}	_{23.79s (± 0.34%)}	_{23.82s (± 0.41%)}	_~	_23.68s	_23.95s	_{p=0.574 n=6}
_{ts-pre-modules - node (v18.15.0, x64)}
_Errors	₃₅	₃₅	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_224,565	_224,565	_~	_~	_~	_{p=1.000 n=6}
_Types	_93,734	_93,734	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{369,518k (± 0.03%)}	_{369,412k (± 0.02%)}	_~	_369,312k	_369,477k	_{p=0.093 n=6}
_{Parse Time}	_{2.78s (± 1.87%)}	_{2.77s (± 0.96%)}	_~	_2.72s	_2.80s	_{p=0.126 n=6}
_{Bind Time}	_{1.58s (± 1.03%)}	_{1.58s (± 0.67%)}	_~	_1.56s	_1.59s	_{p=0.451 n=6}
_{Check Time}	_{15.47s (± 0.32%)}	_{15.45s (± 0.39%)}	_~	_15.36s	_15.51s	_{p=0.688 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{19.84s (± 0.27%)}	_{19.79s (± 0.42%)}	_~	_19.65s	_19.87s	_{p=0.261 n=6}
_{vscode - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_2,878,579	_2,878,579	_~	_~	_~	_{p=1.000 n=6}
_Types	_975,166	_975,166	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{3,042,078k (± 0.00%)}	_{3,042,073k (± 0.00%)}	_~	_3,042,019k	_3,042,125k	_{p=0.936 n=6}
_{Parse Time}	_{13.54s (± 0.32%)}	_{13.59s (± 0.23%)}	_~	_13.54s	_13.63s	_{p=0.056 n=6}
_{Bind Time}	_{4.22s (± 2.03%)}	_{4.18s (± 0.21%)}	_~	_4.17s	_4.19s	_{p=0.459 n=6}
_{Check Time}	_{73.36s (± 0.39%)}	_{73.21s (± 0.27%)}	_~	_73.00s	_73.48s	_{p=0.230 n=6}
_{Emit Time}	_{23.98s (± 0.38%)}	_{23.98s (± 0.24%)}	_~	_23.91s	_24.05s	_{p=0.936 n=6}
_{Total Time}	_{115.09s (± 0.30%)}	_{114.96s (± 0.17%)}	_~	_114.79s	_115.31s	_{p=0.378 n=6}
_{webpack - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_267,117	_267,117	_~	_~	_~	_{p=1.000 n=6}
_Types	_108,775	_108,775	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{411,543k (± 0.01%)}	_{411,524k (± 0.02%)}	_~	_411,431k	_411,593k	_{p=0.810 n=6}
_{Parse Time}	_{3.19s (± 0.54%)}	_{3.19s (± 0.55%)}	_~	_3.17s	_3.22s	_{p=0.870 n=6}
_{Bind Time}	_{1.42s (± 0.59%)}	_{1.41s (± 0.37%)}	_~	_1.41s	_1.42s	_{p=0.533 n=6}
_{Check Time}	_{14.20s (± 0.37%)}	_{14.22s (± 0.51%)}	_~	_14.13s	_14.30s	_{p=0.520 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{18.80s (± 0.21%)}	_{18.83s (± 0.36%)}	_~	_18.76s	_18.91s	_{p=0.521 n=6}
_{xstate-main - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_525,251	_525,251	_~	_~	_~	_{p=1.000 n=6}
_Types	_178,574	_178,574	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{462,859k (± 0.09%)}	_{462,680k (± 0.08%)}	_~	_462,336k	_463,129k	_{p=0.471 n=6}
_{Parse Time}	_{3.17s (± 0.68%)}	_{3.16s (± 0.99%)}	_~	_3.13s	_3.21s	_{p=0.418 n=6}
_{Bind Time}	_{1.17s (± 1.14%)}	_1.17s	_~	_~	_~	_{p=0.599 n=6}
_{Check Time}	_{17.99s (± 0.24%)}	_{17.95s (± 0.33%)}	_~	_17.89s	_18.03s	_{p=0.296 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{22.34s (± 0.16%)}	_{22.28s (± 0.33%)}	_~	_22.20s	_22.38s	_{p=0.228 n=6}

System info unknown

Hosts

node (v18.15.0, x64)

Scenarios

Compiler-Unions - node (v18.15.0, x64)
angular-1 - node (v18.15.0, x64)
mui-docs - node (v18.15.0, x64)
self-build-src - node (v18.15.0, x64)
self-build-src-public-api - node (v18.15.0, x64)
self-compiler - node (v18.15.0, x64)
ts-pre-modules - node (v18.15.0, x64)
vscode - node (v18.15.0, x64)
webpack - node (v18.15.0, x64)
xstate-main - node (v18.15.0, x64)

_Benchmark	_Name	_Iterations
_Current	_pr	₆
_Baseline	_baseline	₆

Developer Information:

Download Benchmarks

TypeScript Bot (typescript-bot) · 2024-06-27T03:03:51Z

Daniel Rosenwasser (@DanielRosenwasser) Here are the results of running the top 400 repos with tsc comparing main and refs/pull/59045/merge:

Everything looks good!

Mateusz Burzyński (Andarist) · 2024-06-27T09:13:50Z

I already have a very related change to this open here. Both PRs touch the same area of the code and solve very overlapping problems, I think it would make sense to merge both

Jake Bailey (jakebailey) · 2024-07-16T19:52:16Z

Seems fine to me, but does need a sync from main and baseline update.

…ions

Ron Buckton (rbuckton) requested review from Anders Hejlsberg (ahejlsberg) and Wesley Wigham (weswigham)June 26, 2024 22:35

TypeScript Bot (typescript-bot) assigned Ron Buckton (rbuckton)Jun 26, 2024

TypeScript Bot (typescript-bot) added Author: Team For Uncommitted Bug PR for untriaged, rejected, closed or missing bug labels Jun 26, 2024

Ron Buckton (rbuckton) mentioned this pull request Jul 16, 2024
Use destructured names as fallback labels when expanding parameters #57619
Closed

TypeScript Bot (typescript-bot) added For Backlog Bug PRs that fix a backlog bug and removed For Uncommitted Bug PR for untriaged, rejected, closed or missing bug labels Jul 16, 2024

Ron Buckton (rbuckton) requested review from Daniel Rosenwasser (DanielRosenwasser) and Jake Bailey (jakebailey)July 16, 2024 19:32

Ron Buckton (rbuckton) added 3 commits July 16, 2024 15:57

Get tuple labels for rest elements from array binding patterns
9b5a768

Additional test cases and better nameing for object patterns and elis…
14d82b8
…ions

More reliable name disambiguation, update baselines
ae645c3

Ron Buckton (rbuckton)force-pushed the tuple-name-from-binding-element branch from a497918 to ae645c3Compare July 17, 2024 01:05

Fix formatting
f2640f3

Jake Bailey (jakebailey) approved these changes Jul 17, 2024
View reviewed changes

Ron Buckton (rbuckton) merged commit 369f2b0 into mainJul 17, 2024

Ron Buckton (rbuckton) deleted the tuple-name-from-binding-element branch July 17, 2024 19:13

Jake Bailey (jakebailey) mentioned this pull request Jul 18, 2024
Add TReturn/TNext to Iterable et al #58243
Merged

Ron Buckton (rbuckton) mentioned this pull request Jul 19, 2024
Use tuple name inference for Iterator.next et al #59360
Merged

Nathan Shively-Sanders (sandersn) removed this from PR Backlog Apr 22, 2025

Microsoft (microsoft) locked as resolved and limited conversation to collaborators Oct 16, 2025

Navigation Menu

Uh oh!

Derive tuple labels for rest elements from array binding patterns - #59045

Derive tuple labels for rest elements from array binding patterns#59045
Ron Buckton (rbuckton) merged 4 commits into
mainfrom
tuple-name-from-binding-element

Ron Buckton (rbuckton) commented Jun 26, 2024•
edited by jakebailey
Loading

Uh oh!

Daniel Rosenwasser (DanielRosenwasser) commented Jun 27, 2024

Uh oh!

TypeScript Bot (typescript-bot) commented Jun 27, 2024•
edited
Loading

Uh oh!

TypeScript Bot (typescript-bot) commented Jun 27, 2024

Uh oh!

TypeScript Bot (typescript-bot) commented Jun 27, 2024

Uh oh!

TypeScript Bot (typescript-bot) commented Jun 27, 2024

tsc

Uh oh!

TypeScript Bot (typescript-bot) commented Jun 27, 2024

Uh oh!

Mateusz Burzyński (Andarist) commented Jun 27, 2024

Uh oh!

Jake Bailey (jakebailey) commented Jul 16, 2024

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

6 participants

Uh oh!

Conversation

Ron Buckton (rbuckton) commented Jun 26, 2024• edited by jakebailey Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Daniel Rosenwasser (DanielRosenwasser) commented Jun 27, 2024

Uh oh!

TypeScript Bot (typescript-bot) commented Jun 27, 2024• edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

TypeScript Bot (typescript-bot) commented Jun 27, 2024

Uh oh!

TypeScript Bot (typescript-bot) commented Jun 27, 2024

Uh oh!

TypeScript Bot (typescript-bot) commented Jun 27, 2024

tsc

Uh oh!

TypeScript Bot (typescript-bot) commented Jun 27, 2024

Uh oh!

Mateusz Burzyński (Andarist) commented Jun 27, 2024

Uh oh!

Jake Bailey (jakebailey) commented Jul 16, 2024

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

6 participants

Ron Buckton (rbuckton) commented Jun 26, 2024•
edited by jakebailey
Loading

TypeScript Bot (typescript-bot) commented Jun 27, 2024•
edited
Loading