build: remove awk

.gitignore

@@ -9,4 +9,5 @@
 *.txt
 
 vendor/
-/removecomments
+/removecomments
+/snake2camel

makefile

@@ -15,18 +15,24 @@ clean:
 .PHONY: images
 images: docs/urn.png
 
+.PHONY: snake2camel
+snake2camel:
+	@cd ./tools/snake2camel; go build -o ../../snake2camel .
+
 .PHONY: removecomments
 removecomments:
 	@cd ./tools/removecomments; go build -o ../../removecomments .
 
 machine.go: machine.go.rl
 
+machine.go: snake2camel
+
 machine.go: removecomments
 
 machine.go:
 	$(RAGEL) -Z -G2 -e -o $@ $<
 	@./removecomments $@
-	$(MAKE) -s file=$@ snake2camel
+	@./snake2camel $@
 	$(GOFMT) $@
 
 docs/urn.dot: machine.go.rl
@@ -41,13 +47,5 @@ bench: *_test.go machine.go
 	go test -bench=. -benchmem -benchtime=5s ./...
 
 .PHONY: tests
-tests: *_test.go 
+tests: *_test.go
 	$(GO_TEST) ./...
-
-.PHONY: snake2camel
-snake2camel:
-	@awk -i inplace '{ \
-	while ( match($$0, /(.*)([a-z]+[0-9]*)_([a-zA-Z0-9])(.*)/, cap) ) \
-	$$0 = cap[1] cap[2] toupper(cap[3]) cap[4]; \
-	print \
-	}' $(file)

tools/snake2camel/go.mod

@@ -0,0 +1,3 @@
+module github.com/leodido/go-urn/tools/snake2camel
+
+go 1.21.6

tools/snake2camel/snake2camel.go

@@ -0,0 +1,69 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"regexp"
+	"strings"
+)
+
+func exitWithError(msg string) {
+	err := fmt.Sprintf("error: %s\n", msg)
+	fmt.Fprintln(os.Stderr, err)
+	os.Exit(1)
+}
+
+func replaceAllStringSubmatchFunc(re *regexp.Regexp, str string, repl func([]string) string) (string, int) {
+	result := ""
+	lastIndex := 0
+
+	for _, v := range re.FindAllSubmatchIndex([]byte(str), -1) {
+		groups := []string{}
+		for i := 0; i < len(v); i += 2 {
+			if v[i] == -1 || v[i+1] == -1 {
+				groups = append(groups, "")
+			} else {
+				groups = append(groups, str[v[i]:v[i+1]])
+			}
+		}
+
+		result += str[lastIndex:v[0]] + repl(groups)
+		lastIndex = v[1]
+	}
+
+	return result + str[lastIndex:], lastIndex
+}
+
+func snake2camel(content []byte) []byte {
+	re := regexp.MustCompile(`(.*)([a-z]+[0-9]*)_([a-zA-Z0-9])(.*)`)
+	res := string(content)
+	last := -1
+
+	for last != 0 {
+		res, last = replaceAllStringSubmatchFunc(re, res, func(groups []string) string {
+			return groups[1] + groups[2] + strings.ToUpper(groups[3]) + groups[4]
+		})
+	}
+
+	return []byte(res)
+}
+
+func snake2camelFile(path string) error {
+	content, err := os.ReadFile(path)
+	if err != nil {
+		return err
+	}
+	updated := snake2camel(content)
+
+	return os.WriteFile(path, updated, 0)
+}
+
+func main() {
+	if len(os.Args) != 2 {
+		exitWithError("must be called with the file path as the only argument")
+	}
+	path := os.Args[1]
+	if err := snake2camelFile(path); err != nil {
+		exitWithError(err.Error())
+	}
+}

tools/snake2camel/snake2camel_test.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestSnake2CamelNoReplace(t *testing.T) {
+	txt := `const start int = 1`
+
+	exp := `const start int = 1`
+
+	got := snake2camel([]byte(txt))
+	if string(got) != exp {
+		fmt.Printf("expected length: %d, got %d\n", len(exp), len(got))
+		t.Fatalf("expected:\n%s\ngot:\n%s", exp, got)
+	}
+}
+
+func TestSnake2CamelOneUnderscore(t *testing.T) {
+	txt := `const en_urn int = 5
+	const en_scim int = 44
+	const en_fail int = 81
+	const en_main int = 1`
+
+	exp := `const enUrn int = 5
+	const enScim int = 44
+	const enFail int = 81
+	const enMain int = 1`
+
+	got := snake2camel([]byte(txt))
+	if string(got) != exp {
+		fmt.Printf("expected length: %d, got %d\n", len(exp), len(got))
+		t.Fatalf("expected:\n%s\ngot:\n%s", exp, got)
+	}
+}
+
+func TestSnake2CamelMoreUnderscores(t *testing.T) {
+	txt := `if (m.p) == (m.pe) {
+		goto _test_eof
+	}
+	switch m.cs {
+	case 1:
+		goto st_case_1
+	}`
+
+	exp := `if (m.p) == (m.pe) {
+		goto _testEof
+	}
+	switch m.cs {
+	case 1:
+		goto stCase1
+	}`
+
+	got := snake2camel([]byte(txt))
+	if string(got) != exp {
+		fmt.Printf("expected length: %d, got %d\n", len(exp), len(got))
+		t.Fatalf("expected:\n%s\ngot:\n%s", exp, got)
+	}
+}

urn.go

@@ -17,8 +17,8 @@ const errInvalidURN = "invalid URN: %s"
 // Details at https://tools.ietf.org/html/rfc2141.
 type URN struct {
 	prefix string // Static prefix. Equal to "urn" when empty.
-	ID     string // Namespace identifier
-	SS     string // Namespace specific string
+	ID     string // Namespace identifier (NID)
+	SS     string // Namespace specific string (NSS)
 	norm   string // Normalized namespace specific string
 }
 
@@ -71,7 +71,7 @@ func (u URN) MarshalJSON() ([]byte, error) {
 	return json.Marshal(u.String())
 }
 
-// MarshalJSON unmarshals a URN from JSON string form (e.g. `"urn:oid:1.2.3.4"`).
+// UnmarshalJSON unmarshals a URN from JSON string form (e.g. `"urn:oid:1.2.3.4"`).
 func (u *URN) UnmarshalJSON(bytes []byte) error {
 	var str string
 	if err := json.Unmarshal(bytes, &str); err != nil {