better treatment of variant relative pronouns in Eng, based on suggestions by DrBean in gf-dev

lib/src/english/ExtraEng.gf

@@ -48,16 +48,6 @@ concrete ExtraEng of ExtraEngAbs = CatEng **
       insertObj (\\a => vpi.s ! vv.typ ! a) (predVV vv) ;
 
   lin
-    that_RP = 
-    { s = table {
-        RC _ (NCase Gen)    => "whose" ; 
-        RC _ _      => "that" ;
-        _           => "that"   ---- "in that" ?
---        RPrep Neutr => "which" ;
---        RPrep _     => "whom"
-        } ;
-      a = RNoAg
-      } ;
 
     each_Det = mkDeterminer Sg "each" ;
     any_Quant = mkQuant "any" "any" ;
@@ -283,4 +273,44 @@ lin
         g = cn.g
         } ;
 
-} 
+  that_RP =
+     { s = table {
+        RC _ (NCase Gen) | RC _ NPNomPoss => "whose" ; 
+        RC Neutr _  => "that" ;
+        RC _ NPAcc    => "that" ;
+        RC _ (NCase Nom)    => "that" ;
+        RPrep Neutr => "which" ;
+        RPrep _     => "who"
+        } ;
+      a = RNoAg
+      } ;
+
+  who_RP =
+     { s = table {
+        RC _ (NCase Gen) | RC _ NPNomPoss => "whose" ; 
+        _     => "who"
+        } ;
+      a = RNoAg
+      } ;
+      
+  which_RP =
+     { s = table {
+        RC _ (NCase Gen) | RC _ NPNomPoss => "whose" ; 
+        _     => "which"
+        } ;
+      a = RNoAg
+      } ;
+
+  emptyRP =
+     { s = table {
+        RC _ (NCase Gen) | RC _ NPNomPoss => "whose" ; 
+        RC _ NPAcc    => [] ;
+        RC _ (NCase Nom)    => "that" ;
+        RPrep Neutr => "which" ;
+        RPrep _     => "who"
+        } ;
+      a = RNoAg
+      } ;
+
+
+}

lib/src/english/ExtraEngAbs.gf

@@ -8,7 +8,10 @@ abstract ExtraEngAbs = Extra - [ProDrop] ** {
 
     CompoundCN : CN -> CN -> CN ;       -- rock album
 
-    that_RP : RP ; -- "that" as a relational pronoun (IdRP is "which" / "who")
+    that_RP : RP ;  -- "that" as a relational pronoun (IdRP is "which" / "who")
+    which_RP : RP ; -- force "which"
+    who_RP : RP ;   -- force "who" ; in Acc, also "who": "the girl who I saw"
+    emptyRP : RP ;  -- empty RP in Acc position: "the girl I saw"
 
     each_Det : Det ;
     any_Quant : Quant ;

lib/src/english/ResEng.gf

@@ -37,7 +37,7 @@ resource ResEng = ParamX ** open Prelude in {
 -- for "himself"/"herself"/"itself".
 
   param
-    Agr = AgP1 Number | AgP2 Number | AgP3Sg Gender | AgP3Pl ;
+    Agr = AgP1 Number | AgP2 Number | AgP3Sg Gender | AgP3Pl Gender ;
 
   param 
     Gender = Neutr | Masc | Fem ;
@@ -101,14 +101,14 @@ param
         P2 => AgP2 n ;
         P3 => case n of {
           Sg => AgP3Sg g ;
-          Pl => AgP3Pl
+          Pl => AgP3Pl g
           }
         } ;
 
     fromAgr : Agr -> {n : Number ; p : Person ; g : Gender} = \a -> case a of {
       AgP1 n => {n = n ; p = P1 ; g = Masc} ;
       AgP2 n => {n = n ; p = P2 ; g = Masc} ;
-      AgP3Pl => {n = Pl ; p = P3 ; g = Masc} ;
+      AgP3Pl g => {n = Pl ; p = P3 ; g = g} ;
       AgP3Sg g => {n = Sg ; p = P3 ; g = g}
       } ;
 
@@ -523,7 +523,7 @@ param
     AgP3Sg Neutr => "itself" ;
     AgP1 Pl      => "ourselves" ;
     AgP2 Pl      => "yourselves" ;
-    AgP3Pl       => "themselves"
+    AgP3Pl _     => "themselves"
     } ;
 
 -- For $Sentence$.

lib/src/translator/ExtensionsEng.gf

@@ -122,16 +122,6 @@ lin
       s = s.s ! QDir ++ frontComma ++ t.s ++ cl.s ! t.t ! t.a ! CPos ! oDir
     } ;
 
-  that_RP = {
-    s = \\_ => "that" ;
-    a = RNoAg
-    } ;
-
-  who_RP = {
-    s = \\_ => "who" ;
-    a = RNoAg
-    } ;
-
   CompS s = {s = \\_ => "that" ++ s.s} ;
   CompQS qs = {s = \\_ => qs.s ! QIndir} ;
   CompVP ant p vp = {s = \\a => ant.s ++ p.s ++ 

lib/src/translator/TranslateEng.gf

@@ -84,14 +84,7 @@ lin
   PPos = {s = [] ; p = CPos} ;
   PNeg = {s = [] ; p = CNeg True} | {s = [] ; p = CNeg False} ;
 
-  IdRP = ExtensionsEng.that_RP | G.IdRP | ExtensionsEng.who_RP |
+  IdRP = E.that_RP | G.IdRP | E.who_RP | E.emptyRP ; --- "that" safest when gender is not known
-     { s = table {
-        RC _ (NCase Gen) | RC _ NPNomPoss => "whose" ; 
-        RC _ NPAcc    => [] ;
-        _     => "which"
-        } ;
-      a = RNoAg
-      } ;
 
   DetNP d = G.DetNP d | G.DetCN d (UseN (mkN "one")) ; -- I like this / I like this one ; it / the one