Add Is*Language for better hints

git-svn-id: https://cld2.googlecode.com/svn/trunk@12 b252ecd4-b096-bf77-eb8e-91563289f87e

internal/lang_script.cc

@@ -254,10 +254,13 @@ const char* ExtLanguageDeclaredName(const Language lang) {
   return LanguageDeclaredName(lang);
 }
 
+
+extern const int kCloseSetSize = 10;
+
 // Returns which set of statistically-close languages lang is in. 0 means none.
 int LanguageCloseSet(Language lang) {
   // Scaffolding
-  // id ms         # INDONESIAN MALAY coef=0.4698        Problematic w/o extra words
+  // id ms         # INDONESIAN MALAY coef=0.4698    Problematic w/o extra words
   // bo dz         # TIBETAN DZONGKHA coef=0.4571
   // cs sk         # CZECH SLOVAK coef=0.4273
   // zu xh         # ZULU XHOSA coef=0.3716
@@ -337,6 +340,17 @@ Language FromPerScriptNumber(ULScript ulscript, uint8 perscript_number) {
   }
 }
 
+// Return true if language can be in the Latin script
+bool IsLatnLanguage(Language lang) {
+  if (lang >= kLanguageToPLangSize) {return false;}
+  return (lang == kPLangToLanguageLatn[kLanguageToPLang[lang]]);
+}
+
+// Return true if language can be in a non-Latin script
+bool IsOthrLanguage(Language lang) {
+  if (lang >= kLanguageToPLangSize) {return false;}
+  return (lang == kPLangToLanguageOthr[kLanguageToPLang[lang]]);
+}
 
 
 //----------------------------------------------------------------------------//

internal/lang_script.h

@@ -109,9 +109,6 @@ int LScript4(ULScript ulscript);
 //
 // The Language enum includes the fake language numbers for RTypeNone above.
 //
-// In an open-source environment, the Google-specific Language enum is not
-// available. Language decouples the two environments while maintaining
-// internal compatibility.
 
 
 // If the input is out of range or otherwise unrecognized, it is treated
@@ -168,6 +165,16 @@ Language DefaultLanguage(ULScript ulscript);
 uint8 PerScriptNumber(ULScript ulscript, Language lang);
 Language FromPerScriptNumber(ULScript ulscript, uint8 perscript_number);
 
+// While the speed-sensitive processing deals with per-script language numbers,
+// there is a need for low-performance dealing with original language numbers
+// and unknown scripts, mostly for processing language hints.
+// These routines let one derive a script class from a bare language.
+// For languages written in multiple scripts, both of tehse can return true.
+
+bool IsLatnLanguage(Language lang);
+bool IsOthrLanguage(Language lang);
+
+
 //----------------------------------------------------------------------------//
 // Other                                                                      //
 //----------------------------------------------------------------------------//