document coercions
authornoschinl
Thu, 28 Jul 2011 05:52:28 -0200
changeset 43994 5de4bde3ad41
parent 43993 b141d7a3d4e3
child 43995 c479836d9048
document coercions
doc-src/IsarRef/Thy/HOL_Specific.thy
doc-src/IsarRef/Thy/document/HOL_Specific.tex
doc-src/manual.bib
--- a/doc-src/IsarRef/Thy/HOL_Specific.thy	Wed Jul 27 20:28:00 2011 +0200
+++ b/doc-src/IsarRef/Thy/HOL_Specific.thy	Thu Jul 28 05:52:28 2011 -0200
@@ -1283,6 +1283,63 @@
 
 *}
 
+section {* Coercive subtyping *}
+
+text {*
+  \begin{matharray}{rcl}
+    @{attribute_def (HOL) coercion} & : & @{text attribute} \\
+    @{attribute_def (HOL) coercion_enabled} & : & @{text attribute} \\
+    @{attribute_def (HOL) coercion_map} & : & @{text attribute} \\
+  \end{matharray}
+
+  @{rail "
+    @@{attribute (HOL) coercion} (@{syntax term})?
+    ;
+  "}
+  @{rail "
+    @@{attribute (HOL) coercion_map} (@{syntax term})?
+    ;
+  "}
+
+  Coercive subtyping allows the user to omit explicit type conversions,
+  also called \emph{coercions}.  Type inference will add them as
+  necessary when parsing a term. See
+  \cite{traytel-berghofer-nipkow-2011} for details.
+
+  \begin{description}
+
+  \item @{attribute (HOL) "coercion"}~@{text "f"} registers a new
+  coercion function @{text "f :: \<sigma>\<^isub>1 \<Rightarrow>
+  \<sigma>\<^isub>2"} where @{text "\<sigma>\<^isub>1"} and @{text
+  "\<sigma>\<^isub>2"} are nullary type constructors. Coercions are
+  composed by the inference algorithm if needed. Note that the type
+  inference algorithm is complete only if the registered coercions form
+  a lattice.
+
+
+  \item @{attribute (HOL) "coercion_map"}~@{text "map"} registers a new
+  map function to lift coercions through type constructors. The function
+  @{text "map"} must conform to the following type pattern
+
+  \begin{matharray}{lll}
+    @{text "map"} & @{text "::"} &
+      @{text "f\<^isub>1 \<Rightarrow> \<dots> \<Rightarrow> f\<^isub>n \<Rightarrow> (\<alpha>\<^isub>1, \<dots>, \<alpha>\<^isub>n) t \<Rightarrow> (\<beta>\<^isub>1, \<dots>, \<beta>\<^isub>n) t"} \\
+  \end{matharray}
+
+  where @{text "t"} is a type constructor and @{text "f\<^isub>i"} is of
+  type @{text "\<alpha>\<^isub>i \<Rightarrow> \<beta>\<^isub>i"} or
+  @{text "\<beta>\<^isub>i \<Rightarrow> \<alpha>\<^isub>i"}.
+  Registering a map function overwrites any existing map function for
+  this particular type constructor.
+
+
+  \item @{attribute (HOL) "coercion_enabled"} enables the coercion
+  inference algorithm.
+
+  \end{description}
+
+*}
+
 section {* Arithmetic proof support *}
 
 text {*
--- a/doc-src/IsarRef/Thy/document/HOL_Specific.tex	Wed Jul 27 20:28:00 2011 +0200
+++ b/doc-src/IsarRef/Thy/document/HOL_Specific.tex	Thu Jul 28 05:52:28 2011 -0200
@@ -1849,6 +1849,75 @@
 \end{isamarkuptext}%
 \isamarkuptrue%
 %
+\isamarkupsection{Coercive subtyping%
+}
+\isamarkuptrue%
+%
+\begin{isamarkuptext}%
+\begin{matharray}{rcl}
+    \indexdef{HOL}{attribute}{coercion}\hypertarget{attribute.HOL.coercion}{\hyperlink{attribute.HOL.coercion}{\mbox{\isa{coercion}}}} & : & \isa{attribute} \\
+    \indexdef{HOL}{attribute}{coercion\_enabled}\hypertarget{attribute.HOL.coercion-enabled}{\hyperlink{attribute.HOL.coercion-enabled}{\mbox{\isa{coercion{\isaliteral{5F}{\isacharunderscore}}enabled}}}} & : & \isa{attribute} \\
+    \indexdef{HOL}{attribute}{coercion\_map}\hypertarget{attribute.HOL.coercion-map}{\hyperlink{attribute.HOL.coercion-map}{\mbox{\isa{coercion{\isaliteral{5F}{\isacharunderscore}}map}}}} & : & \isa{attribute} \\
+  \end{matharray}
+
+  \begin{railoutput}
+\rail@begin{2}{}
+\rail@term{\hyperlink{attribute.HOL.coercion}{\mbox{\isa{coercion}}}}[]
+\rail@bar
+\rail@nextbar{1}
+\rail@nont{\hyperlink{syntax.term}{\mbox{\isa{term}}}}[]
+\rail@endbar
+\rail@end
+\end{railoutput}
+
+  \begin{railoutput}
+\rail@begin{2}{}
+\rail@term{\hyperlink{attribute.HOL.coercion-map}{\mbox{\isa{coercion{\isaliteral{5F}{\isacharunderscore}}map}}}}[]
+\rail@bar
+\rail@nextbar{1}
+\rail@nont{\hyperlink{syntax.term}{\mbox{\isa{term}}}}[]
+\rail@endbar
+\rail@end
+\end{railoutput}
+
+
+  Coercive subtyping allows the user to omit explicit type conversions,
+  also called \emph{coercions}.  Type inference will add them as
+  necessary when parsing a term. See
+  \cite{traytel-berghofer-nipkow-2011} for details.
+
+  \begin{description}
+
+  \item \hyperlink{attribute.HOL.coercion}{\mbox{\isa{coercion}}}~\isa{{\isaliteral{22}{\isachardoublequote}}f{\isaliteral{22}{\isachardoublequote}}} registers a new
+  coercion function \isa{{\isaliteral{22}{\isachardoublequote}}f\ {\isaliteral{3A}{\isacharcolon}}{\isaliteral{3A}{\isacharcolon}}\ {\isaliteral{5C3C7369676D613E}{\isasymsigma}}\isaliteral{5C3C5E697375623E}{}\isactrlisub {\isadigit{1}}\ {\isaliteral{5C3C52696768746172726F773E}{\isasymRightarrow}}\ {\isaliteral{5C3C7369676D613E}{\isasymsigma}}\isaliteral{5C3C5E697375623E}{}\isactrlisub {\isadigit{2}}{\isaliteral{22}{\isachardoublequote}}} where \isa{{\isaliteral{22}{\isachardoublequote}}{\isaliteral{5C3C7369676D613E}{\isasymsigma}}\isaliteral{5C3C5E697375623E}{}\isactrlisub {\isadigit{1}}{\isaliteral{22}{\isachardoublequote}}} and \isa{{\isaliteral{22}{\isachardoublequote}}{\isaliteral{5C3C7369676D613E}{\isasymsigma}}\isaliteral{5C3C5E697375623E}{}\isactrlisub {\isadigit{2}}{\isaliteral{22}{\isachardoublequote}}} are nullary type constructors. Coercions are
+  composed by the inference algorithm if needed. Note that the type
+  inference algorithm is complete only if the registered coercions form
+  a lattice.
+
+
+  \item \hyperlink{attribute.HOL.coercion-map}{\mbox{\isa{coercion{\isaliteral{5F}{\isacharunderscore}}map}}}~\isa{{\isaliteral{22}{\isachardoublequote}}map{\isaliteral{22}{\isachardoublequote}}} registers a new
+  map function to lift coercions through type constructors. The function
+  \isa{{\isaliteral{22}{\isachardoublequote}}map{\isaliteral{22}{\isachardoublequote}}} must conform to the following type pattern
+
+  \begin{matharray}{lll}
+    \isa{{\isaliteral{22}{\isachardoublequote}}map{\isaliteral{22}{\isachardoublequote}}} & \isa{{\isaliteral{22}{\isachardoublequote}}{\isaliteral{3A}{\isacharcolon}}{\isaliteral{3A}{\isacharcolon}}{\isaliteral{22}{\isachardoublequote}}} &
+      \isa{{\isaliteral{22}{\isachardoublequote}}f\isaliteral{5C3C5E697375623E}{}\isactrlisub {\isadigit{1}}\ {\isaliteral{5C3C52696768746172726F773E}{\isasymRightarrow}}\ {\isaliteral{5C3C646F74733E}{\isasymdots}}\ {\isaliteral{5C3C52696768746172726F773E}{\isasymRightarrow}}\ f\isaliteral{5C3C5E697375623E}{}\isactrlisub n\ {\isaliteral{5C3C52696768746172726F773E}{\isasymRightarrow}}\ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{5C3C616C7068613E}{\isasymalpha}}\isaliteral{5C3C5E697375623E}{}\isactrlisub {\isadigit{1}}{\isaliteral{2C}{\isacharcomma}}\ {\isaliteral{5C3C646F74733E}{\isasymdots}}{\isaliteral{2C}{\isacharcomma}}\ {\isaliteral{5C3C616C7068613E}{\isasymalpha}}\isaliteral{5C3C5E697375623E}{}\isactrlisub n{\isaliteral{29}{\isacharparenright}}\ t\ {\isaliteral{5C3C52696768746172726F773E}{\isasymRightarrow}}\ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{5C3C626574613E}{\isasymbeta}}\isaliteral{5C3C5E697375623E}{}\isactrlisub {\isadigit{1}}{\isaliteral{2C}{\isacharcomma}}\ {\isaliteral{5C3C646F74733E}{\isasymdots}}{\isaliteral{2C}{\isacharcomma}}\ {\isaliteral{5C3C626574613E}{\isasymbeta}}\isaliteral{5C3C5E697375623E}{}\isactrlisub n{\isaliteral{29}{\isacharparenright}}\ t{\isaliteral{22}{\isachardoublequote}}} \\
+  \end{matharray}
+
+  where \isa{{\isaliteral{22}{\isachardoublequote}}t{\isaliteral{22}{\isachardoublequote}}} is a type constructor and \isa{{\isaliteral{22}{\isachardoublequote}}f\isaliteral{5C3C5E697375623E}{}\isactrlisub i{\isaliteral{22}{\isachardoublequote}}} is of
+  type \isa{{\isaliteral{22}{\isachardoublequote}}{\isaliteral{5C3C616C7068613E}{\isasymalpha}}\isaliteral{5C3C5E697375623E}{}\isactrlisub i\ {\isaliteral{5C3C52696768746172726F773E}{\isasymRightarrow}}\ {\isaliteral{5C3C626574613E}{\isasymbeta}}\isaliteral{5C3C5E697375623E}{}\isactrlisub i{\isaliteral{22}{\isachardoublequote}}} or
+  \isa{{\isaliteral{22}{\isachardoublequote}}{\isaliteral{5C3C626574613E}{\isasymbeta}}\isaliteral{5C3C5E697375623E}{}\isactrlisub i\ {\isaliteral{5C3C52696768746172726F773E}{\isasymRightarrow}}\ {\isaliteral{5C3C616C7068613E}{\isasymalpha}}\isaliteral{5C3C5E697375623E}{}\isactrlisub i{\isaliteral{22}{\isachardoublequote}}}.
+  Registering a map function overwrites any existing map function for
+  this particular type constructor.
+
+
+  \item \hyperlink{attribute.HOL.coercion-enabled}{\mbox{\isa{coercion{\isaliteral{5F}{\isacharunderscore}}enabled}}} enables the coercion
+  inference algorithm.
+
+  \end{description}%
+\end{isamarkuptext}%
+\isamarkuptrue%
+%
 \isamarkupsection{Arithmetic proof support%
 }
 \isamarkuptrue%
--- a/doc-src/manual.bib	Wed Jul 27 20:28:00 2011 +0200
+++ b/doc-src/manual.bib	Thu Jul 28 05:52:28 2011 -0200
@@ -1570,6 +1570,15 @@
   year = 2007,
   publisher = Springer}
 
+@unpublished{traytel-berghofer-nipkow-2011,
+  author = {D. Traytel and S. Berghofer and T. Nipkow},
+  title = {Extending Hindley-Milner Type Inference with Coercive
+      Subtyping (long version)},
+  year = 2011,
+  note = {Submitted,
+      \url{http://isabelle.in.tum.de/doc/implementation.pdf}}},
+}
+
 @Unpublished{Trybulec:1993:MizarFeatures,
   author = 	 {A. Trybulec},
   title = 	 {Some Features of the {Mizar} Language},