Fix regex for numbers to support negative numbers

processor/regex.go

@@ -80,7 +80,21 @@ func (p *RegexProcessor) ProcessContent(content string, pattern string, luaExpr
 		log.Printf("Pattern modified to include (?s): %s", pattern)
 	}
 
-	pattern = strings.ReplaceAll(pattern, "!num", `"?(\d*\.?\d+)"?`)
+	// The order of these replaces is important
+	// This one handles !num-s inside of named capture groups
+	// If it were not here our !num in a named capture group would
+	// Expand to another capture group in the capture group
+	// We really only want one (our named) capture group
+	namedGroupNum := regexp.MustCompile(`(?:(\?<[^>]+>)(!num))`)
+	pattern = namedGroupNum.ReplaceAllStringFunc(pattern, func(match string) string {
+		parts := namedGroupNum.FindStringSubmatch(match)
+		if len(parts) != 3 {
+			return match
+		}
+		replacement := `-?\d*\.?\d+`
+		return parts[1] + replacement
+	})
+	pattern = strings.ReplaceAll(pattern, "!num", `"?(-?\d*\.?\d+)"?`)
 	pattern = strings.ReplaceAll(pattern, "!any", `.*?`)
 	repPattern := regexp.MustCompile(`!rep\(([^,]+),\s*(\d+)\)`)
 	// !rep(pattern, count) repeats the pattern n times

processor/regex_test.go

@@ -581,6 +581,39 @@ func TestNamedCaptureGroups(t *testing.T) {
 	}
 }
 
+func TestNamedCaptureGroupsNum(t *testing.T) {
+	content := `<config>
+    <item>
+        <value>100</value>
+    </item>
+</config>`
+
+	expected := `<config>
+    <item>
+        <value>200</value>
+    </item>
+</config>`
+
+	p := &RegexProcessor{}
+	result, mods, matches, err := p.ProcessContent(content, `(?s)<value>(?<amount>!num)</value>`, "amount = amount * 2")
+
+	if err != nil {
+		t.Fatalf("Error processing content: %v", err)
+	}
+
+	if matches != 1 {
+		t.Errorf("Expected 1 match, got %d", matches)
+	}
+
+	if mods != 1 {
+		t.Errorf("Expected 1 modification, got %d", mods)
+	}
+
+	if result != expected {
+		t.Errorf("Expected content to be:\n%s\n\nGot:\n%s", expected, result)
+	}
+}
+
 func TestMultipleNamedCaptureGroups(t *testing.T) {
 	content := `<product>
     <name>Widget</name>