Add benchmarks

benchmarks/run.ps1

@@ -0,0 +1,81 @@
+$ErrorActionPreference = 'Stop'
+Set-Location $PSScriptRoot
+
+$benchmarks = @(
+  @{ Name='arith_loop'; YesNt='arith_loop.ynt'; Py='arith_loop.py'; Js='arith_loop.js' },
+  @{ Name='func_call_loop'; YesNt='func_call_loop.ynt'; Py='func_call_loop.py'; Js='func_call_loop.js' },
+  @{ Name='list_ops'; YesNt='list_ops.ynt'; Py='list_ops.py'; Js='list_ops.js' }
+)
+
+$commands = @(
+  @{ Lang='YesNt'; Build={ param($b) "dotnet ../YesNt.Interpreter.App/bin/Release/net10.0/yesnt.dll $($b.YesNt)" } },
+  @{ Lang='Python'; Build={ param($b) "python $($b.Py)" } },
+  @{ Lang='Node'; Build={ param($b) "node $($b.Js)" } }
+)
+
+function Invoke-Timed([string]$command) {
+  $sw = [System.Diagnostics.Stopwatch]::StartNew()
+  cmd /c $command > $null
+  $sw.Stop()
+
+  if ($LASTEXITCODE -ne 0) {
+    throw "Command failed with exit code ${LASTEXITCODE}: $command"
+  }
+
+  return [double]$sw.Elapsed.TotalMilliseconds
+}
+
+$iterations = 8
+$results = @()
+
+foreach ($benchmark in $benchmarks) {
+  foreach ($command in $commands) {
+    $cmd = & $command.Build $benchmark
+
+    [void](Invoke-Timed $cmd) # warm-up run
+
+    $times = @()
+    for ($i = 0; $i -lt $iterations; $i++) {
+      $times += Invoke-Timed $cmd
+    }
+
+    $sorted = $times | Sort-Object
+    $mean = ($times | Measure-Object -Average).Average
+    $median = if ($iterations % 2 -eq 0) {
+      ($sorted[$iterations / 2 - 1] + $sorted[$iterations / 2]) / 2
+    } else {
+      $sorted[[int]($iterations / 2)]
+    }
+
+    $results += [pscustomobject]@{
+      Benchmark = $benchmark.Name
+      Language = $command.Lang
+      MeanMs = [math]::Round($mean, 2)
+      MedianMs = [math]::Round($median, 2)
+      MinMs = [math]::Round($sorted[0], 2)
+      MaxMs = [math]::Round($sorted[-1], 2)
+    }
+  }
+}
+
+$results = $results | Sort-Object Benchmark, Language
+$results | Format-Table -AutoSize
+
+Write-Host "`nRelative slowdown (lower baseline is better):"
+$slowdowns = foreach ($name in ($results.Benchmark | Select-Object -Unique)) {
+  $group = $results | Where-Object Benchmark -eq $name
+  $yesnt = ($group | Where-Object Language -eq 'YesNt').MeanMs
+  $python = ($group | Where-Object Language -eq 'Python').MeanMs
+  $node = ($group | Where-Object Language -eq 'Node').MeanMs
+
+  [pscustomobject]@{
+    Benchmark = $name
+    YesNt_vs_Python_x = [math]::Round($yesnt / $python, 1)
+    YesNt_vs_Node_x = [math]::Round($yesnt / $node, 1)
+  }
+}
+
+$slowdowns | Format-Table -AutoSize
+
+Write-Host "`nCSV:"
+$results | ConvertTo-Csv -NoTypeInformation