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(* Title: HOL/Imperative_HOL/Heap_Monad.thy
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Author: John Matthews, Galois Connections; Alexander Krauss, Lukas Bulwahn & Florian Haftmann, TU Muenchen
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*)
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header {* A monad with a polymorphic heap and primitive reasoning infrastructure *}
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theory Heap_Monad
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imports Heap Monad_Syntax
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begin
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subsection {* The monad *}
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subsubsection {* Monad construction *}
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text {* Monadic heap actions either produce values
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and transform the heap, or fail *}
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datatype 'a Heap = Heap "heap \<Rightarrow> ('a \<times> heap) option"
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primrec execute :: "'a Heap \<Rightarrow> heap \<Rightarrow> ('a \<times> heap) option" where
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[code del]: "execute (Heap f) = f"
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lemma Heap_cases [case_names succeed fail]:
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fixes f and h
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assumes succeed: "\<And>x h'. execute f h = Some (x, h') \<Longrightarrow> P"
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assumes fail: "execute f h = None \<Longrightarrow> P"
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shows P
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using assms by (cases "execute f h") auto
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lemma Heap_execute [simp]:
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"Heap (execute f) = f" by (cases f) simp_all
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lemma Heap_eqI:
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"(\<And>h. execute f h = execute g h) \<Longrightarrow> f = g"
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by (cases f, cases g) (auto simp: expand_fun_eq)
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ML {* structure Execute_Simps = Named_Thms(
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val name = "execute_simps"
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val description = "simplification rules for execute"
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) *}
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setup Execute_Simps.setup
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lemma execute_Let [execute_simps]:
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"execute (let x = t in f x) = (let x = t in execute (f x))"
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by (simp add: Let_def)
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subsubsection {* Specialised lifters *}
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definition tap :: "(heap \<Rightarrow> 'a) \<Rightarrow> 'a Heap" where
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[code del]: "tap f = Heap (\<lambda>h. Some (f h, h))"
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lemma execute_tap [execute_simps]:
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"execute (tap f) h = Some (f h, h)"
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by (simp add: tap_def)
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definition heap :: "(heap \<Rightarrow> 'a \<times> heap) \<Rightarrow> 'a Heap" where
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[code del]: "heap f = Heap (Some \<circ> f)"
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lemma execute_heap [execute_simps]:
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"execute (heap f) = Some \<circ> f"
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by (simp add: heap_def)
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definition guard :: "(heap \<Rightarrow> bool) \<Rightarrow> (heap \<Rightarrow> 'a \<times> heap) \<Rightarrow> 'a Heap" where
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[code del]: "guard P f = Heap (\<lambda>h. if P h then Some (f h) else None)"
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lemma execute_guard [execute_simps]:
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"\<not> P h \<Longrightarrow> execute (guard P f) h = None"
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"P h \<Longrightarrow> execute (guard P f) h = Some (f h)"
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by (simp_all add: guard_def)
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subsubsection {* Predicate classifying successful computations *}
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definition success :: "'a Heap \<Rightarrow> heap \<Rightarrow> bool" where
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"success f h \<longleftrightarrow> execute f h \<noteq> None"
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lemma successI:
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"execute f h \<noteq> None \<Longrightarrow> success f h"
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by (simp add: success_def)
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lemma successE:
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assumes "success f h"
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obtains r h' where "r = fst (the (execute c h))"
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and "h' = snd (the (execute c h))"
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and "execute f h \<noteq> None"
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using assms by (simp add: success_def)
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ML {* structure Success_Intros = Named_Thms(
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val name = "success_intros"
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val description = "introduction rules for success"
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) *}
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setup Success_Intros.setup
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lemma success_tapI [success_intros]:
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"success (tap f) h"
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by (rule successI) (simp add: execute_simps)
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lemma success_heapI [success_intros]:
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"success (heap f) h"
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by (rule successI) (simp add: execute_simps)
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lemma success_guardI [success_intros]:
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"P h \<Longrightarrow> success (guard P f) h"
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by (rule successI) (simp add: execute_guard)
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lemma success_LetI [success_intros]:
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"x = t \<Longrightarrow> success (f x) h \<Longrightarrow> success (let x = t in f x) h"
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by (simp add: Let_def)
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lemma success_ifI:
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"(c \<Longrightarrow> success t h) \<Longrightarrow> (\<not> c \<Longrightarrow> success e h) \<Longrightarrow>
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success (if c then t else e) h"
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by (simp add: success_def)
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subsubsection {* Predicate for a simple relational calculus *}
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text {*
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The @{text crel} predicate states that when a computation @{text c}
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runs with the heap @{text h} will result in return value @{text r}
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and a heap @{text "h'"}, i.e.~no exception occurs.
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*}
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definition crel :: "'a Heap \<Rightarrow> heap \<Rightarrow> heap \<Rightarrow> 'a \<Rightarrow> bool" where
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crel_def: "crel c h h' r \<longleftrightarrow> Heap_Monad.execute c h = Some (r, h')"
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lemma crelI:
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"Heap_Monad.execute c h = Some (r, h') \<Longrightarrow> crel c h h' r"
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by (simp add: crel_def)
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lemma crelE:
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assumes "crel c h h' r"
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obtains "r = fst (the (execute c h))"
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and "h' = snd (the (execute c h))"
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and "success c h"
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proof (rule that)
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from assms have *: "execute c h = Some (r, h')" by (simp add: crel_def)
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then show "success c h" by (simp add: success_def)
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from * have "fst (the (execute c h)) = r" and "snd (the (execute c h)) = h'"
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by simp_all
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then show "r = fst (the (execute c h))"
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and "h' = snd (the (execute c h))" by simp_all
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qed
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lemma crel_success:
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"crel c h h' r \<Longrightarrow> success c h"
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by (simp add: crel_def success_def)
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lemma success_crelE:
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assumes "success c h"
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obtains r h' where "crel c h h' r"
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using assms by (auto simp add: crel_def success_def)
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lemma crel_deterministic:
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assumes "crel f h h' a"
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and "crel f h h'' b"
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shows "a = b" and "h' = h''"
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using assms unfolding crel_def by auto
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ML {* structure Crel_Intros = Named_Thms(
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val name = "crel_intros"
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val description = "introduction rules for crel"
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) *}
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ML {* structure Crel_Elims = Named_Thms(
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val name = "crel_elims"
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val description = "elimination rules for crel"
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) *}
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setup "Crel_Intros.setup #> Crel_Elims.setup"
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lemma crel_LetI [crel_intros]:
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assumes "x = t" "crel (f x) h h' r"
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shows "crel (let x = t in f x) h h' r"
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using assms by simp
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lemma crel_LetE [crel_elims]:
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assumes "crel (let x = t in f x) h h' r"
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obtains "crel (f t) h h' r"
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using assms by simp
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lemma crel_ifI:
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assumes "c \<Longrightarrow> crel t h h' r"
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and "\<not> c \<Longrightarrow> crel e h h' r"
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shows "crel (if c then t else e) h h' r"
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by (cases c) (simp_all add: assms)
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lemma crel_ifE:
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assumes "crel (if c then t else e) h h' r"
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obtains "c" "crel t h h' r"
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| "\<not> c" "crel e h h' r"
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using assms by (cases c) simp_all
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lemma crel_tapI [crel_intros]:
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assumes "h' = h" "r = f h"
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shows "crel (tap f) h h' r"
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by (rule crelI) (simp add: assms execute_simps)
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lemma crel_tapE [crel_elims]:
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assumes "crel (tap f) h h' r"
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obtains "h' = h" and "r = f h"
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using assms by (rule crelE) (auto simp add: execute_simps)
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lemma crel_heapI [crel_intros]:
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assumes "h' = snd (f h)" "r = fst (f h)"
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shows "crel (heap f) h h' r"
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by (rule crelI) (simp add: assms execute_simps)
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lemma crel_heapE [crel_elims]:
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assumes "crel (heap f) h h' r"
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obtains "h' = snd (f h)" and "r = fst (f h)"
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using assms by (rule crelE) (simp add: execute_simps)
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lemma crel_guardI [crel_intros]:
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assumes "P h" "h' = snd (f h)" "r = fst (f h)"
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shows "crel (guard P f) h h' r"
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by (rule crelI) (simp add: assms execute_simps)
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lemma crel_guardE [crel_elims]:
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assumes "crel (guard P f) h h' r"
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obtains "h' = snd (f h)" "r = fst (f h)" "P h"
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using assms by (rule crelE)
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(auto simp add: execute_simps elim!: successE, cases "P h", auto simp add: execute_simps)
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subsubsection {* Monad combinators *}
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definition return :: "'a \<Rightarrow> 'a Heap" where
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[code del]: "return x = heap (Pair x)"
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lemma execute_return [execute_simps]:
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"execute (return x) = Some \<circ> Pair x"
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by (simp add: return_def execute_simps)
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lemma success_returnI [success_intros]:
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"success (return x) h"
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by (rule successI) (simp add: execute_simps)
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lemma crel_returnI [crel_intros]:
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"h = h' \<Longrightarrow> crel (return x) h h' x"
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by (rule crelI) (simp add: execute_simps)
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lemma crel_returnE [crel_elims]:
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assumes "crel (return x) h h' r"
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obtains "r = x" "h' = h"
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using assms by (rule crelE) (simp add: execute_simps)
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definition raise :: "string \<Rightarrow> 'a Heap" where -- {* the string is just decoration *}
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[code del]: "raise s = Heap (\<lambda>_. None)"
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lemma execute_raise [execute_simps]:
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"execute (raise s) = (\<lambda>_. None)"
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by (simp add: raise_def)
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lemma crel_raiseE [crel_elims]:
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assumes "crel (raise x) h h' r"
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obtains "False"
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using assms by (rule crelE) (simp add: success_def execute_simps)
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definition bind :: "'a Heap \<Rightarrow> ('a \<Rightarrow> 'b Heap) \<Rightarrow> 'b Heap" where
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[code del]: "bind f g = Heap (\<lambda>h. case execute f h of
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Some (x, h') \<Rightarrow> execute (g x) h'
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| None \<Rightarrow> None)"
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setup {*
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Adhoc_Overloading.add_variant
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@{const_name Monad_Syntax.bind} @{const_name Heap_Monad.bind}
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*}
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lemma execute_bind [execute_simps]:
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"execute f h = Some (x, h') \<Longrightarrow> execute (f \<guillemotright>= g) h = execute (g x) h'"
|
haftmann@37709
|
274 |
"execute f h = None \<Longrightarrow> execute (f \<guillemotright>= g) h = None"
|
haftmann@37755
|
275 |
by (simp_all add: bind_def)
|
haftmann@37709
|
276 |
|
haftmann@37771
|
277 |
lemma execute_bind_success:
|
haftmann@37771
|
278 |
"success f h \<Longrightarrow> execute (f \<guillemotright>= g) h = execute (g (fst (the (execute f h)))) (snd (the (execute f h)))"
|
haftmann@37771
|
279 |
by (cases f h rule: Heap_cases) (auto elim!: successE simp add: bind_def)
|
haftmann@37771
|
280 |
|
haftmann@37771
|
281 |
lemma success_bind_executeI:
|
haftmann@37771
|
282 |
"execute f h = Some (x, h') \<Longrightarrow> success (g x) h' \<Longrightarrow> success (f \<guillemotright>= g) h"
|
haftmann@37757
|
283 |
by (auto intro!: successI elim!: successE simp add: bind_def)
|
haftmann@37757
|
284 |
|
haftmann@37771
|
285 |
lemma success_bind_crelI [success_intros]:
|
haftmann@37771
|
286 |
"crel f h h' x \<Longrightarrow> success (g x) h' \<Longrightarrow> success (f \<guillemotright>= g) h"
|
haftmann@37771
|
287 |
by (auto simp add: crel_def success_def bind_def)
|
haftmann@37771
|
288 |
|
haftmann@37771
|
289 |
lemma crel_bindI [crel_intros]:
|
haftmann@37771
|
290 |
assumes "crel f h h' r" "crel (g r) h' h'' r'"
|
haftmann@37771
|
291 |
shows "crel (f \<guillemotright>= g) h h'' r'"
|
haftmann@37771
|
292 |
using assms
|
haftmann@37771
|
293 |
apply (auto intro!: crelI elim!: crelE successE)
|
haftmann@37771
|
294 |
apply (subst execute_bind, simp_all)
|
haftmann@37771
|
295 |
done
|
haftmann@37771
|
296 |
|
haftmann@37771
|
297 |
lemma crel_bindE [crel_elims]:
|
haftmann@37771
|
298 |
assumes "crel (f \<guillemotright>= g) h h'' r'"
|
haftmann@37771
|
299 |
obtains h' r where "crel f h h' r" "crel (g r) h' h'' r'"
|
haftmann@37771
|
300 |
using assms by (auto simp add: crel_def bind_def split: option.split_asm)
|
haftmann@37771
|
301 |
|
haftmann@37771
|
302 |
lemma execute_bind_eq_SomeI:
|
haftmann@37753
|
303 |
assumes "Heap_Monad.execute f h = Some (x, h')"
|
haftmann@37753
|
304 |
and "Heap_Monad.execute (g x) h' = Some (y, h'')"
|
haftmann@37753
|
305 |
shows "Heap_Monad.execute (f \<guillemotright>= g) h = Some (y, h'')"
|
haftmann@37755
|
306 |
using assms by (simp add: bind_def)
|
haftmann@37753
|
307 |
|
haftmann@37709
|
308 |
lemma return_bind [simp]: "return x \<guillemotright>= f = f x"
|
haftmann@37787
|
309 |
by (rule Heap_eqI) (simp add: execute_bind execute_simps)
|
haftmann@37709
|
310 |
|
haftmann@37709
|
311 |
lemma bind_return [simp]: "f \<guillemotright>= return = f"
|
haftmann@37787
|
312 |
by (rule Heap_eqI) (simp add: bind_def execute_simps split: option.splits)
|
haftmann@37709
|
313 |
|
haftmann@37828
|
314 |
lemma bind_bind [simp]: "(f \<guillemotright>= g) \<guillemotright>= k = (f :: 'a Heap) \<guillemotright>= (\<lambda>x. g x \<guillemotright>= k)"
|
haftmann@37787
|
315 |
by (rule Heap_eqI) (simp add: bind_def execute_simps split: option.splits)
|
haftmann@37709
|
316 |
|
haftmann@37709
|
317 |
lemma raise_bind [simp]: "raise e \<guillemotright>= f = raise e"
|
haftmann@37787
|
318 |
by (rule Heap_eqI) (simp add: execute_simps)
|
haftmann@37709
|
319 |
|
haftmann@26170
|
320 |
|
haftmann@37757
|
321 |
subsection {* Generic combinators *}
|
haftmann@26170
|
322 |
|
haftmann@37757
|
323 |
subsubsection {* Assertions *}
|
haftmann@26170
|
324 |
|
haftmann@37709
|
325 |
definition assert :: "('a \<Rightarrow> bool) \<Rightarrow> 'a \<Rightarrow> 'a Heap" where
|
haftmann@37709
|
326 |
"assert P x = (if P x then return x else raise ''assert'')"
|
haftmann@28742
|
327 |
|
haftmann@37757
|
328 |
lemma execute_assert [execute_simps]:
|
haftmann@37753
|
329 |
"P x \<Longrightarrow> execute (assert P x) h = Some (x, h)"
|
haftmann@37753
|
330 |
"\<not> P x \<Longrightarrow> execute (assert P x) h = None"
|
haftmann@37787
|
331 |
by (simp_all add: assert_def execute_simps)
|
haftmann@37753
|
332 |
|
haftmann@37757
|
333 |
lemma success_assertI [success_intros]:
|
haftmann@37757
|
334 |
"P x \<Longrightarrow> success (assert P x) h"
|
haftmann@37757
|
335 |
by (rule successI) (simp add: execute_assert)
|
haftmann@37757
|
336 |
|
haftmann@37771
|
337 |
lemma crel_assertI [crel_intros]:
|
haftmann@37771
|
338 |
"P x \<Longrightarrow> h' = h \<Longrightarrow> r = x \<Longrightarrow> crel (assert P x) h h' r"
|
haftmann@37771
|
339 |
by (rule crelI) (simp add: execute_assert)
|
haftmann@37771
|
340 |
|
haftmann@37771
|
341 |
lemma crel_assertE [crel_elims]:
|
haftmann@37771
|
342 |
assumes "crel (assert P x) h h' r"
|
haftmann@37771
|
343 |
obtains "P x" "r = x" "h' = h"
|
haftmann@37771
|
344 |
using assms by (rule crelE) (cases "P x", simp_all add: execute_assert success_def)
|
haftmann@37771
|
345 |
|
haftmann@28742
|
346 |
lemma assert_cong [fundef_cong]:
|
haftmann@28742
|
347 |
assumes "P = P'"
|
haftmann@28742
|
348 |
assumes "\<And>x. P' x \<Longrightarrow> f x = f' x"
|
haftmann@28742
|
349 |
shows "(assert P x >>= f) = (assert P' x >>= f')"
|
haftmann@37753
|
350 |
by (rule Heap_eqI) (insert assms, simp add: assert_def)
|
haftmann@28742
|
351 |
|
haftmann@37757
|
352 |
|
haftmann@37757
|
353 |
subsubsection {* Plain lifting *}
|
haftmann@37757
|
354 |
|
haftmann@37753
|
355 |
definition lift :: "('a \<Rightarrow> 'b) \<Rightarrow> 'a \<Rightarrow> 'b Heap" where
|
haftmann@37753
|
356 |
"lift f = return o f"
|
haftmann@37709
|
357 |
|
haftmann@37753
|
358 |
lemma lift_collapse [simp]:
|
haftmann@37753
|
359 |
"lift f x = return (f x)"
|
haftmann@37753
|
360 |
by (simp add: lift_def)
|
haftmann@37709
|
361 |
|
haftmann@37753
|
362 |
lemma bind_lift:
|
haftmann@37753
|
363 |
"(f \<guillemotright>= lift g) = (f \<guillemotright>= (\<lambda>x. return (g x)))"
|
haftmann@37753
|
364 |
by (simp add: lift_def comp_def)
|
haftmann@37709
|
365 |
|
haftmann@37757
|
366 |
|
haftmann@37757
|
367 |
subsubsection {* Iteration -- warning: this is rarely useful! *}
|
haftmann@37757
|
368 |
|
haftmann@37755
|
369 |
primrec fold_map :: "('a \<Rightarrow> 'b Heap) \<Rightarrow> 'a list \<Rightarrow> 'b list Heap" where
|
haftmann@37755
|
370 |
"fold_map f [] = return []"
|
krauss@37792
|
371 |
| "fold_map f (x # xs) = do {
|
haftmann@37709
|
372 |
y \<leftarrow> f x;
|
haftmann@37755
|
373 |
ys \<leftarrow> fold_map f xs;
|
haftmann@37709
|
374 |
return (y # ys)
|
krauss@37792
|
375 |
}"
|
haftmann@37709
|
376 |
|
haftmann@37755
|
377 |
lemma fold_map_append:
|
haftmann@37755
|
378 |
"fold_map f (xs @ ys) = fold_map f xs \<guillemotright>= (\<lambda>xs. fold_map f ys \<guillemotright>= (\<lambda>ys. return (xs @ ys)))"
|
haftmann@37753
|
379 |
by (induct xs) simp_all
|
haftmann@37753
|
380 |
|
haftmann@37757
|
381 |
lemma execute_fold_map_unchanged_heap [execute_simps]:
|
haftmann@37753
|
382 |
assumes "\<And>x. x \<in> set xs \<Longrightarrow> \<exists>y. execute (f x) h = Some (y, h)"
|
haftmann@37755
|
383 |
shows "execute (fold_map f xs) h =
|
haftmann@37753
|
384 |
Some (List.map (\<lambda>x. fst (the (execute (f x) h))) xs, h)"
|
haftmann@37753
|
385 |
using assms proof (induct xs)
|
haftmann@37787
|
386 |
case Nil show ?case by (simp add: execute_simps)
|
haftmann@37753
|
387 |
next
|
haftmann@37753
|
388 |
case (Cons x xs)
|
haftmann@37753
|
389 |
from Cons.prems obtain y
|
haftmann@37753
|
390 |
where y: "execute (f x) h = Some (y, h)" by auto
|
haftmann@37755
|
391 |
moreover from Cons.prems Cons.hyps have "execute (fold_map f xs) h =
|
haftmann@37753
|
392 |
Some (map (\<lambda>x. fst (the (execute (f x) h))) xs, h)" by auto
|
haftmann@37787
|
393 |
ultimately show ?case by (simp, simp only: execute_bind(1), simp add: execute_simps)
|
haftmann@37753
|
394 |
qed
|
haftmann@37753
|
395 |
|
haftmann@26182
|
396 |
subsection {* Code generator setup *}
|
haftmann@26182
|
397 |
|
haftmann@26182
|
398 |
subsubsection {* Logical intermediate layer *}
|
haftmann@26182
|
399 |
|
haftmann@37709
|
400 |
primrec raise' :: "String.literal \<Rightarrow> 'a Heap" where
|
haftmann@37709
|
401 |
[code del, code_post]: "raise' (STR s) = raise s"
|
haftmann@26182
|
402 |
|
haftmann@37709
|
403 |
lemma raise_raise' [code_inline]:
|
haftmann@37709
|
404 |
"raise s = raise' (STR s)"
|
haftmann@37709
|
405 |
by simp
|
haftmann@26182
|
406 |
|
haftmann@37709
|
407 |
code_datatype raise' -- {* avoid @{const "Heap"} formally *}
|
haftmann@26182
|
408 |
|
haftmann@26182
|
409 |
|
haftmann@27707
|
410 |
subsubsection {* SML and OCaml *}
|
haftmann@26182
|
411 |
|
haftmann@26752
|
412 |
code_type Heap (SML "unit/ ->/ _")
|
haftmann@37828
|
413 |
code_const bind (SML "!(fn/ f'_/ =>/ fn/ ()/ =>/ f'_/ (_/ ())/ ())")
|
haftmann@27707
|
414 |
code_const return (SML "!(fn/ ()/ =>/ _)")
|
haftmann@37709
|
415 |
code_const Heap_Monad.raise' (SML "!(raise/ Fail/ _)")
|
haftmann@26182
|
416 |
|
haftmann@37753
|
417 |
code_type Heap (OCaml "unit/ ->/ _")
|
haftmann@37828
|
418 |
code_const bind (OCaml "!(fun/ f'_/ ()/ ->/ f'_/ (_/ ())/ ())")
|
haftmann@27707
|
419 |
code_const return (OCaml "!(fun/ ()/ ->/ _)")
|
haftmann@37828
|
420 |
code_const Heap_Monad.raise' (OCaml "failwith")
|
haftmann@27707
|
421 |
|
haftmann@37838
|
422 |
|
haftmann@37838
|
423 |
subsubsection {* Haskell *}
|
haftmann@37838
|
424 |
|
haftmann@37838
|
425 |
text {* Adaption layer *}
|
haftmann@37838
|
426 |
|
haftmann@37838
|
427 |
code_include Haskell "Heap"
|
haftmann@37838
|
428 |
{*import qualified Control.Monad;
|
haftmann@37838
|
429 |
import qualified Control.Monad.ST;
|
haftmann@37838
|
430 |
import qualified Data.STRef;
|
haftmann@37838
|
431 |
import qualified Data.Array.ST;
|
haftmann@37838
|
432 |
|
haftmann@37838
|
433 |
type RealWorld = Control.Monad.ST.RealWorld;
|
haftmann@37838
|
434 |
type ST s a = Control.Monad.ST.ST s a;
|
haftmann@37838
|
435 |
type STRef s a = Data.STRef.STRef s a;
|
haftmann@37838
|
436 |
type STArray s a = Data.Array.ST.STArray s Int a;
|
haftmann@37838
|
437 |
|
haftmann@37838
|
438 |
newSTRef = Data.STRef.newSTRef;
|
haftmann@37838
|
439 |
readSTRef = Data.STRef.readSTRef;
|
haftmann@37838
|
440 |
writeSTRef = Data.STRef.writeSTRef;
|
haftmann@37838
|
441 |
|
haftmann@37838
|
442 |
newArray :: Int -> a -> ST s (STArray s a);
|
haftmann@37838
|
443 |
newArray k = Data.Array.ST.newArray (0, k);
|
haftmann@37838
|
444 |
|
haftmann@37838
|
445 |
newListArray :: [a] -> ST s (STArray s a);
|
haftmann@37838
|
446 |
newListArray xs = Data.Array.ST.newListArray (0, length xs) xs;
|
haftmann@37838
|
447 |
|
haftmann@37838
|
448 |
newFunArray :: Int -> (Int -> a) -> ST s (STArray s a);
|
haftmann@37838
|
449 |
newFunArray k f = Data.Array.ST.newListArray (0, k) (map f [0..k-1]);
|
haftmann@37838
|
450 |
|
haftmann@37838
|
451 |
lengthArray :: STArray s a -> ST s Int;
|
haftmann@37838
|
452 |
lengthArray a = Control.Monad.liftM snd (Data.Array.ST.getBounds a);
|
haftmann@37838
|
453 |
|
haftmann@37838
|
454 |
readArray :: STArray s a -> Int -> ST s a;
|
haftmann@37838
|
455 |
readArray = Data.Array.ST.readArray;
|
haftmann@37838
|
456 |
|
haftmann@37838
|
457 |
writeArray :: STArray s a -> Int -> a -> ST s ();
|
haftmann@37838
|
458 |
writeArray = Data.Array.ST.writeArray;*}
|
haftmann@37838
|
459 |
|
haftmann@37838
|
460 |
code_reserved Haskell Heap
|
haftmann@37838
|
461 |
|
haftmann@37838
|
462 |
text {* Monad *}
|
haftmann@37838
|
463 |
|
haftmann@37838
|
464 |
code_type Heap (Haskell "Heap.ST/ Heap.RealWorld/ _")
|
haftmann@37838
|
465 |
code_monad bind Haskell
|
haftmann@37838
|
466 |
code_const return (Haskell "return")
|
haftmann@37838
|
467 |
code_const Heap_Monad.raise' (Haskell "error")
|
haftmann@37838
|
468 |
|
haftmann@37838
|
469 |
|
haftmann@37838
|
470 |
subsubsection {* Scala *}
|
haftmann@37838
|
471 |
|
haftmann@37842
|
472 |
code_include Scala "Heap"
|
haftmann@37842
|
473 |
{*def bind[A, B](f: Unit => A, g: A => Unit => B): Unit => B = (_: Unit) => g (f ()) ()
|
haftmann@37842
|
474 |
|
haftmann@37842
|
475 |
class Ref[A](x: A) {
|
haftmann@37842
|
476 |
var value = x
|
haftmann@37842
|
477 |
}
|
haftmann@37842
|
478 |
|
haftmann@37842
|
479 |
object Ref {
|
haftmann@37842
|
480 |
def apply[A](x: A): Ref[A] = new Ref[A](x)
|
haftmann@37842
|
481 |
}
|
haftmann@37842
|
482 |
|
haftmann@37842
|
483 |
def lookup[A](r: Ref[A]): A = r.value
|
haftmann@37842
|
484 |
|
haftmann@37842
|
485 |
def update[A](r: Ref[A], x: A): Unit = { r.value = x }*}
|
haftmann@37838
|
486 |
|
haftmann@37838
|
487 |
code_reserved Scala Heap
|
haftmann@37838
|
488 |
|
haftmann@37838
|
489 |
code_type Heap (Scala "Unit/ =>/ _")
|
haftmann@37842
|
490 |
code_const bind (Scala "!Heap.bind((_), (_))")
|
haftmann@37842
|
491 |
code_const return (Scala "('_: Unit)/ =>/ _")
|
haftmann@37838
|
492 |
code_const Heap_Monad.raise' (Scala "!error(_)")
|
haftmann@37838
|
493 |
|
haftmann@37838
|
494 |
|
haftmann@37838
|
495 |
subsubsection {* Target variants with less units *}
|
haftmann@37838
|
496 |
|
haftmann@31870
|
497 |
setup {*
|
haftmann@27707
|
498 |
|
haftmann@31870
|
499 |
let
|
haftmann@27707
|
500 |
|
haftmann@31870
|
501 |
open Code_Thingol;
|
haftmann@27707
|
502 |
|
haftmann@31870
|
503 |
fun imp_program naming =
|
haftmann@31870
|
504 |
|
haftmann@31870
|
505 |
let
|
haftmann@31870
|
506 |
fun is_const c = case lookup_const naming c
|
haftmann@31870
|
507 |
of SOME c' => (fn c'' => c' = c'')
|
haftmann@31870
|
508 |
| NONE => K false;
|
haftmann@37755
|
509 |
val is_bind = is_const @{const_name bind};
|
haftmann@31870
|
510 |
val is_return = is_const @{const_name return};
|
haftmann@31893
|
511 |
val dummy_name = "";
|
haftmann@31870
|
512 |
val dummy_type = ITyVar dummy_name;
|
haftmann@31893
|
513 |
val dummy_case_term = IVar NONE;
|
haftmann@31870
|
514 |
(*assumption: dummy values are not relevant for serialization*)
|
haftmann@31870
|
515 |
val unitt = case lookup_const naming @{const_name Unity}
|
haftmann@31870
|
516 |
of SOME unit' => IConst (unit', (([], []), []))
|
haftmann@31870
|
517 |
| NONE => error ("Must include " ^ @{const_name Unity} ^ " in generated constants.");
|
haftmann@31870
|
518 |
fun dest_abs ((v, ty) `|=> t, _) = ((v, ty), t)
|
haftmann@31870
|
519 |
| dest_abs (t, ty) =
|
haftmann@31870
|
520 |
let
|
haftmann@31870
|
521 |
val vs = fold_varnames cons t [];
|
haftmann@31870
|
522 |
val v = Name.variant vs "x";
|
haftmann@31870
|
523 |
val ty' = (hd o fst o unfold_fun) ty;
|
haftmann@31893
|
524 |
in ((SOME v, ty'), t `$ IVar (SOME v)) end;
|
haftmann@31870
|
525 |
fun force (t as IConst (c, _) `$ t') = if is_return c
|
haftmann@31870
|
526 |
then t' else t `$ unitt
|
haftmann@31870
|
527 |
| force t = t `$ unitt;
|
haftmann@31870
|
528 |
fun tr_bind' [(t1, _), (t2, ty2)] =
|
haftmann@31870
|
529 |
let
|
haftmann@31870
|
530 |
val ((v, ty), t) = dest_abs (t2, ty2);
|
haftmann@31870
|
531 |
in ICase (((force t1, ty), [(IVar v, tr_bind'' t)]), dummy_case_term) end
|
haftmann@31870
|
532 |
and tr_bind'' t = case unfold_app t
|
haftmann@37753
|
533 |
of (IConst (c, (_, ty1 :: ty2 :: _)), [x1, x2]) => if is_bind c
|
haftmann@31870
|
534 |
then tr_bind' [(x1, ty1), (x2, ty2)]
|
haftmann@31870
|
535 |
else force t
|
haftmann@31870
|
536 |
| _ => force t;
|
haftmann@31893
|
537 |
fun imp_monad_bind'' ts = (SOME dummy_name, dummy_type) `|=> ICase (((IVar (SOME dummy_name), dummy_type),
|
haftmann@31870
|
538 |
[(unitt, tr_bind' ts)]), dummy_case_term)
|
haftmann@37753
|
539 |
and imp_monad_bind' (const as (c, (_, tys))) ts = if is_bind c then case (ts, tys)
|
haftmann@31870
|
540 |
of ([t1, t2], ty1 :: ty2 :: _) => imp_monad_bind'' [(t1, ty1), (t2, ty2)]
|
haftmann@31870
|
541 |
| ([t1, t2, t3], ty1 :: ty2 :: _) => imp_monad_bind'' [(t1, ty1), (t2, ty2)] `$ t3
|
haftmann@31870
|
542 |
| (ts, _) => imp_monad_bind (eta_expand 2 (const, ts))
|
haftmann@31870
|
543 |
else IConst const `$$ map imp_monad_bind ts
|
haftmann@31870
|
544 |
and imp_monad_bind (IConst const) = imp_monad_bind' const []
|
haftmann@31870
|
545 |
| imp_monad_bind (t as IVar _) = t
|
haftmann@31870
|
546 |
| imp_monad_bind (t as _ `$ _) = (case unfold_app t
|
haftmann@31870
|
547 |
of (IConst const, ts) => imp_monad_bind' const ts
|
haftmann@31870
|
548 |
| (t, ts) => imp_monad_bind t `$$ map imp_monad_bind ts)
|
haftmann@31870
|
549 |
| imp_monad_bind (v_ty `|=> t) = v_ty `|=> imp_monad_bind t
|
haftmann@31870
|
550 |
| imp_monad_bind (ICase (((t, ty), pats), t0)) = ICase
|
haftmann@31870
|
551 |
(((imp_monad_bind t, ty),
|
haftmann@31870
|
552 |
(map o pairself) imp_monad_bind pats),
|
haftmann@31870
|
553 |
imp_monad_bind t0);
|
haftmann@31870
|
554 |
|
haftmann@31870
|
555 |
in (Graph.map_nodes o map_terms_stmt) imp_monad_bind end;
|
haftmann@27707
|
556 |
|
haftmann@27707
|
557 |
in
|
haftmann@27707
|
558 |
|
haftmann@31870
|
559 |
Code_Target.extend_target ("SML_imp", ("SML", imp_program))
|
haftmann@31870
|
560 |
#> Code_Target.extend_target ("OCaml_imp", ("OCaml", imp_program))
|
haftmann@37838
|
561 |
#> Code_Target.extend_target ("Scala_imp", ("Scala", imp_program))
|
haftmann@27707
|
562 |
|
haftmann@27707
|
563 |
end
|
haftmann@31870
|
564 |
|
haftmann@27707
|
565 |
*}
|
haftmann@27707
|
566 |
|
haftmann@26182
|
567 |
|
haftmann@37757
|
568 |
hide_const (open) Heap heap guard raise' fold_map
|
haftmann@37721
|
569 |
|
haftmann@26170
|
570 |
end
|