src/HOL/Record.thy

replace assoc lists by Symtab.table;

(*  Title:      HOL/Record.thy
    ID:         $Id$
    Author:     Wolfgang Naraschewski and Markus Wenzel, TU Muenchen

Extensible records with structural subtyping in HOL.  See
Tools/record_package.ML for the actual implementation.
*)

Record = Datatype +


(* concrete syntax *)

nonterminals
  ident field_type field_types field fields update updates

syntax
  (*field names*)
  ""                	:: "id => ident"                    		("_")
  ""                	:: "longid => ident"                		("_")

  (*record types*)
  "_field_type"         :: "[ident, type] => field_type"           	("(2_ ::/ _)")
  ""               	:: "field_type => field_types"              	("_")
  "_field_types"	:: "[field_type, field_types] => field_types"   ("_,/ _")
  "_record_type"	:: "field_types => type"                   	("(3'(| _ |'))")
  "_record_type_scheme"	:: "[field_types, type] => type"	("(3'(| _,/ (2... ::/ _) |'))")

  (*records*)
  "_field"          	:: "[ident, 'a] => field"           		("(2_ =/ _)")
  ""                	:: "field => fields"                		("_")
  "_fields"         	:: "[field, fields] => fields"      		("_,/ _")
  "_record"         	:: "fields => 'a"                   		("(3'(| _ |'))")
  "_record_scheme"  	:: "[fields, 'a] => 'a"             	("(3'(| _,/ (2... =/ _) |'))")

  (*record updates*)
  "_update"	    	:: "[ident, 'a] => update"           		("(2_ :=/ _)")
  ""                	:: "update => updates"               		("_")
  "_updates"        	:: "[update, updates] => updates"    		("_,/ _")
  "_record_update"  	:: "['a, updates] => 'b"               	("_/(3'(| _ |'))" [900,0] 900)


(* type class for record extensions *)

axclass more < term
instance unit :: more


(* initialize the package *)

setup
  RecordPackage.setup


end