feat: only compute all free variables during a-conversion

cmd/lambda/lambda.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"os"
+	"runtime/pprof"
 	"time"
 
 	"git.maximhutz.com/max/lambda/internal/cli"
@@ -14,6 +15,14 @@ import (
 
 // Run main application.
 func main() {
+	f, err := os.Create("profile/cpu.prof")
+	cli.HandleError(err)
+	defer f.Close()
+
+	err = pprof.StartCPUProfile(f)
+	cli.HandleError(err)
+	defer pprof.StopCPUProfile()
+
 	options, err := config.FromArgs()
 	cli.HandleError(err)