some more transfer functions included in Grammar

lib/src/abstract/Grammar.gf

@@ -10,7 +10,6 @@ abstract Grammar =
   Adjective,
   Adverb,
   Numeral,
-  NumeralTransfer,
   Sentence, 
   Question,
   Relative,
@@ -19,5 +18,7 @@ abstract Grammar =
   Text,
   Structural,
   Idiom,
-  Tense ;
+  Tense,
+  Transfer 
+  ;
 

lib/src/abstract/Sentence.gf

@@ -9,7 +9,7 @@ abstract Sentence = Cat ** {
 -- Clauses are converted to $S$ (with fixed tense) with the
 -- $UseCl$ function below.
 
-  fun
+  data
     PredVP    : NP -> VP -> Cl ;         -- John walks
 
 -- Using an embedded sentence as a subject is treated separately.

lib/src/abstract/Transfer.gf

@@ -0,0 +1,29 @@
+abstract Transfer = Sentence, Verb, Adverb, Structural, NumeralTransfer ** {
+
+{-
+-- examples of transfer: to test,
+
+  > i LangEng.gf
+
+  > p "she sees him" | pt -transfer=active2passive | l
+  he is seen by her
+
+  > p "wouldn't she see him" | pt -transfer=active2passive | l
+  wouldn't he be seen by her
+
+  > p -cat=NP "3 cats with 4 dogs" | pt -transfer=digits2numeral | l
+  three cats with four dogs
+-}
+
+fun
+  active2passive : Cl -> Cl ;
+def
+  active2passive (PredVP subj (ComplSlash (SlashV2a v) obj)) = 
+    PredVP obj (AdvVP (PassV2 v) (PrepNP by8agent_Prep subj)) ;
+  active2passive (PredVP subj (AdvVP (ComplSlash (SlashV2a v) obj) adv)) = 
+    PredVP obj (AdvVP (AdvVP (PassV2 v) (PrepNP by8agent_Prep subj)) adv) ;
+  active2passive (PredVP subj (AdVVP adv (ComplSlash (SlashV2a v) obj))) = 
+    PredVP obj (AdVVP adv (AdvVP (PassV2 v) (PrepNP by8agent_Prep subj))) ;
+  active2passive cl = cl ;
+
+}

lib/src/abstract/Verb.gf

@@ -7,7 +7,7 @@ abstract Verb = Cat ** {
 -- Verb phrases are constructed from verbs by providing their
 -- complements. There is one rule for each verb category.
 
-  fun
+  data
     UseV     : V   -> VP ;        -- sleep
 
     ComplVV  : VV  -> VP -> VP ;  -- want to run