src/HOL/Record.thy

field-update in records is generalised to take a function on the field
rather than the new value.

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

theory Record
imports Product_Type
uses ("Tools/record_package.ML")
begin

lemma prop_subst: "s = t \<Longrightarrow> PROP P t \<Longrightarrow> PROP P s"
  by simp

lemma rec_UNIV_I: "\<And>x. x\<in>UNIV \<equiv> True"
  by simp

lemma rec_True_simp: "(True \<Longrightarrow> PROP P) \<equiv> PROP P"
  by simp

constdefs K_record:: "'a \<Rightarrow> 'b \<Rightarrow> 'a"
"K_record c x \<equiv> c"

lemma K_record_apply [simp]: "K_record c x = c"
  by (simp add: K_record_def)

lemma K_record_comp [simp]: "(K_record c \<circ> f) = K_record c"
  by (rule ext) (simp add: K_record_apply comp_def)

lemma K_record_cong [cong]: "K_record c x = K_record c x"
  by (rule refl)

subsection {* Concrete record syntax *}

nonterminals
  ident field_type field_types field fields update updates
syntax
  "_constify"           :: "id => ident"                        ("_")
  "_constify"           :: "longid => ident"                    ("_")

  "_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... ::/ _) |'))")

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

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

syntax (xsymbols)
  "_record_type"        :: "field_types => type"                ("(3\<lparr>_\<rparr>)")
  "_record_type_scheme" :: "[field_types, type] => type"        ("(3\<lparr>_,/ (2\<dots> ::/ _)\<rparr>)")
  "_record"             :: "fields => 'a"                               ("(3\<lparr>_\<rparr>)")
  "_record_scheme"      :: "[fields, 'a] => 'a"                 ("(3\<lparr>_,/ (2\<dots> =/ _)\<rparr>)")
  "_record_update"      :: "['a, updates] => 'b"                ("_/(3\<lparr>_\<rparr>)" [900,0] 900)

use "Tools/record_package.ML"
setup RecordPackage.setup

end