build: remove awk

.gitignore

@@ -5,4 +5,5 @@
 vendor/
 .vscode/
 
-/removecomments
+/removecomments
+/snake2camel

makefile

@@ -22,11 +22,7 @@ docs: dots parser/docs/minimal_types.png parser/docs/falco_types.png parser/docs
 
 .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)
+	@go build ./tools/snake2camel
 
 .PHONY: removecomments
 removecomments:
@@ -78,10 +74,12 @@ parser/machine.go: parser/machine.go.rl common/common.rl
 
 parser/machine.go: removecomments
 
+parser/machine.go: snake2camel
+
 parser/machine.go:
 	$(RAGEL) -Z -G2 -e -o $@ $<
 	@./removecomments $@
-	$(MAKE) file=$@ snake2camel
+	@./snake2camel $@
 	$(GOFMT) $@
 
 .PHONY: tests

tools/snake2camel/main.go

@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: Apache-2.0
+//
+// Copyright © 2020- Leonardo Di Donato <leodidonato@gmail.com>
+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())
+	}
+}