Benchmark the input shapes callers actually supply

[twcclegg]

An allocation probe over Parse showed the seed data is the cheapest input the library can be handed:

input	B/op
+16502530000 (E164 — what the benchmark uses)	360
6502530000 national, no prefix	456
020 7031 3000 national with prefix	752
+1 650 253 0000 ext. 123 with extension	1472

PhoneNumberBenchmarkData formats everything to E164, where the national-prefix and extension regexes
both fail — and a failed match returns the shared Match.Empty for free. A successful one allocates
the Match, a GroupCollection and a Group per group. So the two things that dominate a real parse
never run in the benchmark, and any fix for them would measure as zero.

Adds ParseNationalFormat and ParseWithExtension, re-rendering the same numbers via Format.
Separate benchmarks rather than mixing them into ParseOnly: blending would give one number that
can't attribute anything, and ParseOnly stays comparable to the figure tracked across earlier PRs.

Costs two benchmark cases (~45s per tree). Lands before the optimisation so the base commit has a
counterpart to compare against.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.01%. Comparing base (ee09ac6) to head (ec5f50b).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #381   +/-   ##
=======================================
  Coverage   98.01%   98.01%           
=======================================
  Files          39       39           
  Lines       52818    52818           
  Branches     1105     1105           
=======================================
  Hits        51770    51770           
  Misses        795      795           
  Partials      253      253           

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[github-actions]

📊 Benchmark Results

Commit: ec5f50b · Full run · Linux ubuntu-24.04-arm

Both sides were measured on the same runner in the same job, so the numbers are
comparable. Treat sub-percent differences as noise.

PR branch

BenchmarkDotNet v0.15.8, Linux Ubuntu 24.04.4 LTS (Noble Numbat)
Neoverse-N2, 4 physical cores
.NET SDK 10.0.302
  [Host]    : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a
  .NET 10.0 : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a

Job=.NET 10.0  Runtime=.NET 10.0  

Method	PhoneNumberCount	Mean	Error	StdDev	Gen0	Allocated
InputDigitPerKeystroke	1000	4.411 ms	0.0103 ms	0.0096 ms	54.6875	3.87 MB

BenchmarkDotNet v0.15.8, Linux Ubuntu 24.04.4 LTS (Noble Numbat)
Neoverse-N2, 4 physical cores
.NET SDK 10.0.302
  [Host]     : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a
  Job-AMQORM : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a

Runtime=.NET 10.0  InvocationCount=1  IterationCount=20  
LaunchCount=1  RunStrategy=ColdStart  UnrollFactor=1  
WarmupCount=1  

Method	Mean	Error	StdDev	Allocated
CreateInstance	385.0 μs	112.9 μs	130.0 μs	119.48 KB
CreateInstanceAndLoadAllRegions	6,994.3 μs	373.0 μs	429.5 μs	1619.1 KB
FirstRegionLookup	433.9 μs	125.7 μs	144.8 μs	124.54 KB

BenchmarkDotNet v0.15.8, Linux Ubuntu 24.04.4 LTS (Noble Numbat)
Neoverse-N2, 4 physical cores
.NET SDK 10.0.302
  [Host]    : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a
  .NET 10.0 : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a

Job=.NET 10.0  Runtime=.NET 10.0  

Method	PhoneNumberCount	Mean	Error	StdDev	Gen0	Allocated
ExtractPossibleNumber_CleanInput	1000	21.59 μs	0.021 μs	0.019 μs	-	-
ExtractPossibleNumber_WithLeadingJunk	1000	38.41 μs	0.027 μs	0.022 μs	0.6714	48360 B

BenchmarkDotNet v0.15.8, Linux Ubuntu 24.04.4 LTS (Noble Numbat)
Neoverse-N2, 4 physical cores
.NET SDK 10.0.302
  [Host]    : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a
  .NET 10.0 : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a

Job=.NET 10.0  Runtime=.NET 10.0  

Method	PhoneNumberCount	Mean	Error	StdDev	Gen0	Allocated
FindNumbers_Valid	100	139.6 μs	0.32 μs	0.30 μs	0.9766	69.93 KB
FindNumbers_StrictGrouping	100	313.1 μs	0.73 μs	0.69 μs	1.4648	123.2 KB

BenchmarkDotNet v0.15.8, Linux Ubuntu 24.04.4 LTS (Noble Numbat)
Neoverse-N2, 4 physical cores
.NET SDK 10.0.302
  [Host]    : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a
  .NET 10.0 : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a

Job=.NET 10.0  Runtime=.NET 10.0  

Method	PhoneNumberCount	Mean	Error	StdDev	Gen0	Allocated
GetDescriptionForNumber	1000	1,414.87 μs	2.352 μs	1.964 μs	1.9531	196.63 KB
GetDisplayCountry	1000	35.26 μs	0.070 μs	0.062 μs	0.0610	7.56 KB

BenchmarkDotNet v0.15.8, Linux Ubuntu 24.04.4 LTS (Noble Numbat)
Neoverse-N2, 4 physical cores
.NET SDK 10.0.302
  [Host]    : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a
  .NET 10.0 : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a

Job=.NET 10.0  Runtime=.NET 10.0  

Method	PhoneNumberCount	Mean	Error	StdDev	Gen0	Allocated
ParseValidateAndFormatPhoneNumbers	1000	2,583.5 μs	3.15 μs	2.46 μs	7.8125	580.51 KB
ParseOnly	1000	438.2 μs	0.60 μs	0.54 μs	4.8828	350.95 KB
ParseNationalFormat	1000	839.6 μs	1.43 μs	1.34 μs	8.7891	581.22 KB
ParseWithExtension	1000	1,212.3 μs	2.33 μs	2.18 μs	21.4844	1459.2 KB
ValidateOnly	1000	764.5 μs	1.72 μs	1.53 μs	-	41.11 KB
FormatOnly	1000	1,071.8 μs	2.45 μs	2.29 μs	1.9531	187.92 KB

PR base

BenchmarkDotNet v0.15.8, Linux Ubuntu 24.04.4 LTS (Noble Numbat)
Neoverse-N2, 4 physical cores
.NET SDK 10.0.302
  [Host]    : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a
  .NET 10.0 : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a

Job=.NET 10.0  Runtime=.NET 10.0  

Method	PhoneNumberCount	Mean	Error	StdDev	Gen0	Allocated
InputDigitPerKeystroke	1000	4.393 ms	0.0072 ms	0.0060 ms	54.6875	3.87 MB

BenchmarkDotNet v0.15.8, Linux Ubuntu 24.04.4 LTS (Noble Numbat)
Neoverse-N2, 4 physical cores
.NET SDK 10.0.302
  [Host]     : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a
  Job-AMQORM : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a

Runtime=.NET 10.0  InvocationCount=1  IterationCount=20  
LaunchCount=1  RunStrategy=ColdStart  UnrollFactor=1  
WarmupCount=1  

Method	Mean	Error	StdDev	Allocated
CreateInstance	416.4 μs	112.4 μs	129.5 μs	119.48 KB
CreateInstanceAndLoadAllRegions	7,040.6 μs	436.4 μs	502.6 μs	1619.1 KB
FirstRegionLookup	444.5 μs	144.4 μs	166.2 μs	124.54 KB

BenchmarkDotNet v0.15.8, Linux Ubuntu 24.04.4 LTS (Noble Numbat)
Neoverse-N2, 4 physical cores
.NET SDK 10.0.302
  [Host]    : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a
  .NET 10.0 : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a

Job=.NET 10.0  Runtime=.NET 10.0  

Method	PhoneNumberCount	Mean	Error	StdDev	Gen0	Allocated
ExtractPossibleNumber_CleanInput	1000	21.68 μs	0.023 μs	0.022 μs	-	-
ExtractPossibleNumber_WithLeadingJunk	1000	38.25 μs	0.058 μs	0.052 μs	0.6714	48360 B

BenchmarkDotNet v0.15.8, Linux Ubuntu 24.04.4 LTS (Noble Numbat)
Neoverse-N2, 4 physical cores
.NET SDK 10.0.302
  [Host]    : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a
  .NET 10.0 : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a

Job=.NET 10.0  Runtime=.NET 10.0  

Method	PhoneNumberCount	Mean	Error	StdDev	Gen0	Allocated
FindNumbers_Valid	100	140.5 μs	0.23 μs	0.19 μs	0.9766	69.93 KB
FindNumbers_StrictGrouping	100	302.7 μs	0.77 μs	0.69 μs	1.4648	123.2 KB

BenchmarkDotNet v0.15.8, Linux Ubuntu 24.04.4 LTS (Noble Numbat)
Neoverse-N2, 4 physical cores
.NET SDK 10.0.302
  [Host]    : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a
  .NET 10.0 : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a

Job=.NET 10.0  Runtime=.NET 10.0  

Method	PhoneNumberCount	Mean	Error	StdDev	Gen0	Allocated
GetDescriptionForNumber	1000	1,436.30 μs	2.704 μs	2.397 μs	1.9531	196.63 KB
GetDisplayCountry	1000	22.88 μs	0.023 μs	0.022 μs	0.0916	7.56 KB

BenchmarkDotNet v0.15.8, Linux Ubuntu 24.04.4 LTS (Noble Numbat)
Neoverse-N2, 4 physical cores
.NET SDK 10.0.302
  [Host]    : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a
  .NET 10.0 : .NET 10.0.10 (10.0.10, 10.0.1026.32716), Arm64 RyuJIT armv8.0-a

Job=.NET 10.0  Runtime=.NET 10.0  

Method	PhoneNumberCount	Mean	Error	StdDev	Gen0	Allocated
ParseValidateAndFormatPhoneNumbers	1000	2,572.1 μs	4.79 μs	4.48 μs	7.8125	580.51 KB
ParseOnly	1000	435.4 μs	0.59 μs	0.52 μs	4.8828	350.95 KB
ValidateOnly	1000	774.0 μs	1.43 μs	1.20 μs	-	41.11 KB
FormatOnly	1000	1,075.5 μs	3.99 μs	3.73 μs	1.9531	187.92 KB