#NEWLINE# @ expose ( 'make-struct-field-mutator' , [ values_struct . W_StructMutator , values . W_Fixnum , default ( values . W_Object , values . w_false ) ] ) #NEWLINE# def do_make_struct_field_mutator( mutator , field , field_name ) : #NEWLINE# #INDENT# if ( field_name is values . w_false ) : #NEWLINE# #INDENT# return values_struct . W_StructFieldMutator ( mutator , field . value , None ) #NEWLINE# #UNINDENT# if ( not isinstance ( field_name , values . W_Symbol ) ) : #NEWLINE# #INDENT# raise SchemeException ( 'make-struct-field-mutator: expected symbol or #f as argument 2' ) #NEWLINE# #UNINDENT# return values_struct . W_StructFieldMutator ( mutator , field . value , field_name )