feat/schema: add lexer

schema/util/rune.go

@@ -0,0 +1,39 @@
+// Code generated by gocc; DO NOT EDIT.
+
+package util
+
+import (
+	"fmt"
+)
+
+func RuneToString(r rune) string {
+	if r >= 0x20 && r < 0x7f {
+		return fmt.Sprintf("'%c'", r)
+	}
+	switch r {
+	case 0x07:
+		return "'\\a'"
+	case 0x08:
+		return "'\\b'"
+	case 0x0C:
+		return "'\\f'"
+	case 0x0A:
+		return "'\\n'"
+	case 0x0D:
+		return "'\\r'"
+	case 0x09:
+		return "'\\t'"
+	case 0x0b:
+		return "'\\v'"
+	case 0x5c:
+		return "'\\\\\\'"
+	case 0x27:
+		return "'\\''"
+	case 0x22:
+		return "'\\\"'"
+	}
+	if r < 0x10000 {
+		return fmt.Sprintf("\\u%04x", r)
+	}
+	return fmt.Sprintf("\\U%08x", r)
+}