Implement simple parsering

go.mod

@@ -1,3 +1,14 @@
 module datesorter
 
 go 1.23.3
+
+require git.site.quack-lab.dev/dave/cylogger v1.4.0
+
+require (
+	github.com/google/go-cmp v0.5.9 // indirect
+	github.com/hexops/valast v1.5.0 // indirect
+	golang.org/x/mod v0.7.0 // indirect
+	golang.org/x/sys v0.3.0 // indirect
+	golang.org/x/tools v0.4.0 // indirect
+	mvdan.cc/gofumpt v0.4.0 // indirect
+)

go.sum

@@ -0,0 +1,28 @@
+git.site.quack-lab.dev/dave/cylogger v1.4.0 h1:3Ca7V5JWvruARJd5S8xDFwW9LnZ9QInqkYLRdrEFvuY=
+git.site.quack-lab.dev/dave/cylogger v1.4.0/go.mod h1:wctgZplMvroA4X6p8f4B/LaCKtiBcT1Pp+L14kcS8jk=
+github.com/frankban/quicktest v1.14.3 h1:FJKSZTDHjyhriyC81FLQ0LY93eSai0ZyR/ZIkd3ZUKE=
+github.com/frankban/quicktest v1.14.3/go.mod h1:mgiwOwqx65TmIk1wJ6Q7wvnVMocbUorkibMOrVTHZps=
+github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
+github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/hexops/autogold v0.8.1 h1:wvyd/bAJ+Dy+DcE09BoLk6r4Fa5R5W+O+GUzmR985WM=
+github.com/hexops/autogold v0.8.1/go.mod h1:97HLDXyG23akzAoRYJh/2OBs3kd80eHyKPvZw0S5ZBY=
+github.com/hexops/gotextdiff v1.0.3 h1:gitA9+qJrrTCsiCl7+kh75nPqQt1cx4ZkudSTLoUqJM=
+github.com/hexops/gotextdiff v1.0.3/go.mod h1:pSWU5MAI3yDq+fZBTazCSJysOMbxWL1BSow5/V2vxeg=
+github.com/hexops/valast v1.5.0 h1:FBTuvVi0wjTngtXJRZXMbkN/Dn6DgsUsBwch2DUJU8Y=
+github.com/hexops/valast v1.5.0/go.mod h1:Jcy1pNH7LNraVaAZDLyv21hHg2WBv9Nf9FL6fGxU7o4=
+github.com/kr/pretty v0.3.0 h1:WgNl7dwNpEZ6jJ9k1snq4pZsg7DOEN8hP9Xw0Tsjwk0=
+github.com/kr/pretty v0.3.0/go.mod h1:640gp4NfQd8pI5XOwp5fnNeVWj67G7CFk/SaSQn7NBk=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
+github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
+golang.org/x/mod v0.7.0 h1:LapD9S96VoQRhi/GrNTqeBJFrUjs5UHCAtTlgwA5oZA=
+golang.org/x/mod v0.7.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o=
+golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.3.0 h1:w8ZOecv6NaNa/zC8944JTU3vz4u6Lagfk4RPQxv92NQ=
+golang.org/x/sys v0.3.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/tools v0.4.0 h1:7mTAgkunk3fr4GAloyyCasadO6h9zSsQZbwvcaIciV4=
+golang.org/x/tools v0.4.0/go.mod h1:UE5sM2OK9E/d67R0ANs2xJizIymRP5gJU295PvKXxjQ=
+mvdan.cc/gofumpt v0.4.0 h1:JVf4NN1mIpHogBj7ABpgOyZc65/UUOkKQFkoURsz4MM=
+mvdan.cc/gofumpt v0.4.0/go.mod h1:PljLOHDeZqgS8opHRKLzp2It2VBuSdteAgqUfzMTxlQ=

main.go

@@ -0,0 +1,75 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"regexp"
+	"time"
+
+	logger "git.site.quack-lab.dev/dave/cylogger"
+)
+
+type DateParser interface {
+	Parse(s string) (time.Time, error)
+}
+
+type DateParser8 struct {
+	re *regexp.Regexp
+}
+
+func (dp *DateParser8) Parse(s string) (time.Time, error) {
+	matches := dp.re.FindStringSubmatch(s)
+	if len(matches) == 0 {
+		return time.Time{}, fmt.Errorf("no match")
+	}
+	return time.Parse("20060102", matches[0])
+}
+
+type DateParserISO struct {
+	re *regexp.Regexp
+}
+
+func (dp *DateParserISO) Parse(s string) (time.Time, error) {
+	matches := dp.re.FindStringSubmatch(s)
+	if len(matches) == 0 {
+		return time.Time{}, fmt.Errorf("no match")
+	}
+	return time.Parse("2006-01-02", matches[0])
+}
+
+func main() {
+	flag.Parse()
+	logger.InitFlag()
+
+	if flag.NArg() == 0 {
+		logger.Error("no files provided")
+		return
+	}
+
+	parsers := []DateParser{
+		&DateParser8{re: regexp.MustCompile(`\d{8}`)},
+		&DateParserISO{re: regexp.MustCompile(`\d{4}-\d{2}-\d{2}`)},
+	}
+
+	files := flag.Args()
+
+	for _, file := range files {
+		logger.Info("processing file: %s", file)
+		date, err := parseDate(file, parsers)
+		if err != nil {
+			logger.Error("error parsing date: %s", err)
+			continue
+		}
+		logger.Info("date: %s", date)
+	}
+}
+
+func parseDate(file string, parsers []DateParser) (time.Time, error) {
+	for _, parser := range parsers {
+		date, err := parser.Parse(file)
+		if err == nil {
+			return date, nil
+		}
+	}
+	return time.Time{}, fmt.Errorf("no date found")
+}