Adding field update feature

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/api/api_datatype.cpp

@@ -618,4 +618,25 @@ extern "C" {
         Z3_CATCH_RETURN(0);
     }
 
+    Z3_ast Z3_datatype_update_field(
+        __in Z3_context c,  __in Z3_func_decl f, __in Z3_ast t, __in Z3_ast v) {        
+        Z3_TRY;
+        LOG_Z3_datatype_update_field(c, f, t, v);
+        RESET_ERROR_CODE();
+        ast_manager & m = mk_c(c)->m();
+        func_decl* _f      = to_func_decl(f);
+        expr* _t = to_expr(t);
+        expr* _v = to_expr(v);  
+        expr* args[2] = { _t, _v };
+        sort* domain[2] = { m.get_sort(_t), m.get_sort(_v) };
+        parameter param(_f);
+        func_decl * d = m.mk_func_decl(mk_c(c)->get_array_fid(), OP_DT_UPDATE_FIELD, 1, &param, 2, domain);
+        app* r = m.mk_app(d, 2, args);
+        mk_c(c)->save_ast_trail(r);
+        check_sorts(c, r);
+        RETURN_Z3(of_ast(r));
+        Z3_CATCH_RETURN(0);
+    }
+
+
 };

src/api/dotnet/Context.cs

@@ -449,6 +449,19 @@ namespace Microsoft.Z3
             return MkDatatypeSorts(MkSymbols(names), c);
         }
 
+        /// <summary>
+        /// Update a datatype field at expression t with value v.
+	/// The function performs a record update at t. The field
+	/// that is passed in as argument is updated with value v,
+	/// the remainig fields of t are unchanged.	
+        /// </summary>
+	public Expr MkUpdateField(FuncDecl field, Expr t, Expr v) 
+	{
+	    return Expr.Create(this, Native.Z3_datatype_update_field(
+	                                  nCtx, field.NativeObject,
+                                          t.NativeObject, v.NativeObject));		
+	}
+
         #endregion
         #endregion
 

src/api/java/Context.java

@@ -375,6 +375,22 @@ public class Context extends IDisposable
         return mkDatatypeSorts(MkSymbols(names), c);
     }
 
+    /**
+     * Update a datatype field at expression t with value v.
+     * The function performs a record update at t. The field
+     * that is passed in as argument is updated with value v,
+     * the remainig fields of t are unchanged.	
+     **/
+    public Expr MkUpdateField(FuncDecl field, Expr t, Expr v) 
+    {
+	return Expr.Create
+	    (this, 
+	     Native.datatypeUpdateField
+	     (nCtx(), field.getNativeObject(),
+	      t.getNativeObject(), v.getNativeObject()));		
+    }
+
+
     /**
      * Creates a new function declaration.
      **/

src/api/z3_api.h

@@ -877,6 +877,8 @@ typedef enum
 
       - Z3_OP_DT_ACCESSOR: datatype accessor.
 
+      - Z3_OP_DT_UPDATE_FIELD: datatype field update.
+
       - Z3_OP_PB_AT_MOST: Cardinality constraint. 
               E.g., x + y + z <= 2
       
@@ -1066,6 +1068,7 @@ typedef enum {
     Z3_OP_DT_CONSTRUCTOR=0x800,
     Z3_OP_DT_RECOGNISER,
     Z3_OP_DT_ACCESSOR,
+    Z3_OP_DT_UPDATE_FIELD,
 
     // Pseudo Booleans
     Z3_OP_PB_AT_MOST=0x900,
@@ -3751,6 +3754,28 @@ END_MLAPI_EXCLUDE
     Z3_func_decl Z3_API Z3_get_datatype_sort_constructor_accessor(
         __in Z3_context c, __in Z3_sort t, unsigned idx_c, unsigned idx_a);
 
+    /**
+       \brief Update record field with a value.
+
+       This corresponds to the 'with' construct in OCaml. 
+       It has the effect of updating a record field with a given value.
+       The remaining fields are left unchanged. It is the record
+       equivalent of an array store (see \sa Z3_mk_store).
+       If the datatype has more than one constructor, then the update function
+       behaves as identity if there is a miss-match between the accessor and
+       constructor. For example ((_ update-field car) nil 1) is nil, 
+       while ((_ update-field car) (cons 2 nil) 1) is (cons 1 nil).
+
+
+       \pre Z3_get_sort_kind(Z3_get_sort(c, t)) == Z3_get_domain(c, field_access, 1) == Z3_DATATYPE_SORT
+       \pre Z3_get_sort(c, value) == Z3_get_range(c, field_access)
+
+
+       def_API('Z3_datatype_update_field', AST, (_in(CONTEXT), _in(FUNC_DECL), _in(AST), _in(AST)))
+    */
+    Z3_ast Z3_API Z3_datatype_update_field(
+        __in Z3_context c,  __in Z3_func_decl field_access, 
+        __in Z3_ast t, __in Z3_ast value);
 
     /**
         \brief Return arity of relation.