(Som) Add empty Str field to NP so every NP contributes with some string

Otherwise parsing sentences with pronoun  objects gives metavariables.

src/somali/NounSom.gf

@@ -44,7 +44,8 @@ DetCN det cn = useN cn ** {
   -- : PN -> NP ;
   UsePN pn = pn ** {
     s = \\c => pn.s ;
-    isPron = False
+    isPron = False ;
+    empty = [] ;
     } ;
 
   -- : Pron -> NP ;
@@ -73,7 +74,7 @@ DetCN det cn = useN cn ** {
 -- Determiners can form noun phrases directly.
 
   -- : Det -> NP ;
-  DetNP det = {
+  DetNP det = emptyNP ** {
     s = det.sp ! Masc ; ---- Any way to decide for gender here?
     a = getAgr det.n Masc ;
     isPron = False ;

src/somali/ResSom.gf

@@ -136,6 +136,7 @@ oper
   BaseNP : Type = {
     a : Agreement ;
     isPron : Bool ;
+    empty : Str ;
     } ;
 
   NounPhrase : Type = BaseNP ** {s : Case => Str} ;
@@ -143,12 +144,14 @@ oper
   useN : Noun -> CNoun ** BaseNP = \n -> n **
     { mod = \\_,_ => [] ; hasMod = False ;
       a = Sg3 (gender n) ; isPron,isPoss = False ;
+      empty = [] ;
     } ;
 
   emptyNP : NounPhrase = {
     s = \\_ => [] ;
     a = Pl3 ;
-    isPron = False
+    isPron = False ;
+    empty = [] ;
     } ;
 
   impersNP : NounPhrase = emptyNP ** {
@@ -172,46 +175,55 @@ oper
     Sg1 => {
       s = table {Nom => "aan" ; Abs => "i"} ;
       a = Sg1 ; isPron = True ; sp = "aniga" ;
+      empty = [] ;
       poss = {s = quantTable "ayg" "ayd" ; short = quantTable "ay" ; sp = gnTable "ayg" "ayd" "uwayg"}
       } ;
     Sg2 => {
       s = table {Nom => "aad" ; Abs => "ku"} ;
       a = Sg2 ; isPron = True ; sp ="adiga" ;
+      empty = [] ;
       poss = {s = quantTable "aag" "aad" ; short = quantTable "aa" ; sp = gnTable "aag" "aad" "uwaag"}
       } ;
     Sg3 Masc => {
       s = table {Nom => "uu" ; Abs => []} ;
       a = Sg3 Masc ; isPron = True ; sp ="isaga" ;
+      empty = [] ;
       poss = {s, short = quantTable "iis" ; sp = gnTable "iis" "iis" "uwiis"}
       } ;
     Sg3 Fem => {
       s = table {Nom => "ay" ; Abs => []} ;
       a = Sg3 Fem ; isPron = True ; sp = "iyada" ;
+      empty = [] ;
       poss = {s, short = quantTable "eed" ; sp = gnTable "eed" "eed" "uweed"}
       } ;
     Pl1 Excl => {
       s = table {Nom => "aan" ; Abs => "na"} ;
       a = Pl1 Excl ; isPron = True ; sp ="annaga" ;
+      empty = [] ;
       poss = {s = quantTable "eenn" ; short = quantTable "een" ; sp = gnTable "eenn" "eenn" "uweenn"}
       } ;
     Pl1 Incl => {
       s = table {Nom => "aynu" ; Abs => "ina"} ;
       a = Pl1 Incl ; isPron = True ; sp ="innaga" ;
+      empty = [] ;
       poss = {s = quantTable "eenn" ; short = quantTable "een" ; sp = gnTable "eenn" "eenn" "uweenn"}
       } ;
     Pl2 => {
       s = table {Nom => "aad" ; Abs => "idin"} ;
       a =  Pl2 ; isPron = True ; sp ="idinka" ;
+      empty = [] ;
       poss = {s = quantTable "iinn" ; short = quantTable "iin" ; sp = gnTable "iinn" "iinn" "uwiinn"}
       } ;
     Pl3 => {
       s = table {Nom => "ay" ; Abs => []} ;
       a = Pl3 ; isPron = True ; sp = "iyaga" ;
+      empty = [] ;
       poss = {s, short = quantTable "ood" ; sp = gnTable "ood" "ood" "uwood"}
       } ;
     Impers => {
       s = table {Nom => "la" ; Abs => "??"} ;
       a = Impers ; isPron = True ; sp = "??" ;
+      empty = [] ;
       poss = {s, short = quantTable "??" ; sp = gnTable "??" "??" "??"}
       }
     } ;
@@ -684,8 +696,8 @@ oper
   insertComp : VPSlash -> NounPhrase -> VerbPhrase = \vp,np ->
     let noun : Str = case <np.isPron,np.a> of {
           <False,_>          => np.s ! Abs ;
-        --  <True,(Sg3 _|Pl3)> => (pronTable ! np.a).sp ; -- uncomment if you want to add long object pronoun for 3rd person object
+        --  <True,(Sg3 _|Pl3)> => np.empty ++ (pronTable ! np.a).sp ; -- uncomment if you want to add long object pronoun for 3rd person object
-          _ => [] } -- no long object for other pronouns
+          _ => np.empty } -- no long object for other pronouns
     in case vp.obj2.a of {
       Unassigned =>
         vp ** {obj2 = {