Better case for Script (#153)

* [language] use a better convention for scripts constants

* [fontscan] bump format version since the Script binary encoding has changed

fontscan/serialize.go

@@ -185,7 +185,7 @@ func (ff *fileFootprints) deserializeFrom(src []byte) error {
 	return nil
 }
 
-const cacheFormatVersion = 3
+const cacheFormatVersion = 4
 
 func max(i, j int) int {
 	if i > j {

language/scripts.go

@@ -11,13 +11,17 @@ import (
 // Note that the default value is usually the Unknown script, not the 0 value (which is invalid)
 type Script uint32
 
-// ParseScript simply converts a 4 bytes string into its binary encoding.
+// ParseScript converts a 4 bytes string into its binary encoding,
+// enforcing the conventional capitalized case.
 // If [script] is longer, only its 4 first bytes are used.
 func ParseScript(script string) (Script, error) {
 	if len(script) < 4 {
 		return 0, fmt.Errorf("invalid script string: %s", script)
 	}
-	return Script(binary.BigEndian.Uint32([]byte(script))), nil
+	s := binary.BigEndian.Uint32([]byte(script))
+	// ensure capitalized case : make first letter upper, others lower
+	const mask uint32 = 0x20000000
+	return Script(s & ^mask | 0x00202020), nil
 }
 
 // LookupScript looks up the script for a particular character (as defined by