ProgTutorial/Recipes/Antiquotes.thy
changeset 191 0150cf5982ae
parent 189 069d525f8f1d
child 292 41a802bbb7df
--- a/ProgTutorial/Recipes/Antiquotes.thy	Thu Mar 19 17:50:28 2009 +0100
+++ b/ProgTutorial/Recipes/Antiquotes.thy	Thu Mar 19 23:21:26 2009 +0100
@@ -3,29 +3,31 @@
 imports "../Base"
 begin
 
-
 section {* Useful Document Antiquotations *}
 
 text {*
-  (FIXME: update to to new antiquotation setup)
-
   {\bf Problem:} 
   How to keep your ML-code inside a document synchronised with the actual code?\smallskip
 
-  {\bf Solution:} This can be achieved using document antiquotations.\smallskip
+  {\bf Solution:} This can be achieved with document antiquotations.\smallskip
 
   Document antiquotations can be used for ensuring consistent type-setting of
   various entities in a document. They can also be used for sophisticated
-  \LaTeX-hacking. If you type @{text "Ctrl-c Ctrl-a h A"} inside ProofGeneral, you
-  obtain a list of all currently available document antiquotations and their options.
-  You obtain the same list on the ML-level by typing
+  \LaTeX-hacking. If you type on the Isabelle level
+*}
+
+print_antiquotations
 
-  @{ML [display,gray] "ThyOutput.print_antiquotations ()"}
+text {*
+  you obtain a list of all currently available document antiquotations and
+  their options.  
 
-  Below we give the code for two additional document antiquotations that can
-  be used to typeset ML-code and also to check whether the given code actually
-  compiles. This provides a sanity check for the code and also allows one to
-  keep documents in sync with other code, for example Isabelle.
+  Below we will give the code for two additional document
+  antiquotations both of which are intended to typeset ML-code. The crucial point
+  of these document antiquotations is that they not just print the ML-code, but also 
+  check whether it compiles. This will provide a sanity check for the code
+  and also allows you to keep documents in sync with other code, for example
+  Isabelle.
 
   We first describe the antiquotation @{text "ML_checked"} with the syntax:
  
@@ -47,19 +49,20 @@
 val _ = ThyOutput.antiquotation "ML_checked" (Scan.lift Args.name) output_ml*}
 
 text {*
-  The parser @{ML "(Scan.lift Args.name)"} in line 9 parses a string, in this
-  case the code. As mentioned before, the code is sent to the ML-compiler in
-  the line 4 using the function @{ML ml_val}, which constructs the appropriate
-  ML-expression.  If the code is ``approved'' by the compiler, then the output
-  function @{ML "ThyOutput.output"} in the next line pretty prints the
-  code. This function expects that the code is a list of (pretty)strings where
-  each string correspond to a line in the output. Therefore the use of @{ML
-  "(space_explode \"\\n\" txt)" for txt} which produces this list according to
-  linebreaks.  There are a number of options for antiquotations that are
-  observed by @{ML ThyOutput.output} when printing the code (including @{text
-  "[display]"} and @{text "[quotes]"}). Line 7 sets up the new document
-  antiquotation.
-
+  The parser @{ML "(Scan.lift Args.name)"} in Line 7 parses a string, in this
+  case the code, and then calls the function @{ML output_ml}. As mentioned
+  before, the parsed code is sent to the ML-compiler in Line 4 using the
+  function @{ML ml_val}, which constructs the appropriate ML-expression, and
+  using @{ML "eval_in" in ML_Context}, which calls the compiler.  If the code is
+  ``approved'' by the compiler, then the output function @{ML "output" in
+  ThyOutput} in the next line pretty prints the code. This function expects
+  that the code is a list of (pretty)strings where each string correspond to a
+  line in the output. Therefore the use of @{ML "(space_explode \"\\n\" txt)"
+  for txt} which produces such a list according to linebreaks.  There are a
+  number of options for antiquotations that are observed by the function 
+  @{ML "output" in ThyOutput} when printing the code (including @{text "[display]"} 
+  and @{text "[quotes]"}). The function @{ML "antiquotation" in ThyOutput} in 
+  Line 7 sets up the new document antiquotation.
 
   \begin{readmore}
   For more information about options of document antiquotations see \rsccite{sec:antiq}).
@@ -82,30 +85,28 @@
   parser @{ML OuterParse.position} encodes the positional information in the 
   result.
 
-  We can now write in a document @{text "@{ML_checked \"2 + 3\"}"} in order to
+  We can now write @{text "@{ML_checked \"2 + 3\"}"} in a document in order to
   obtain @{ML_checked "2 + 3"} and be sure that this code compiles until
-  somebody changes the definition of \mbox{@{ML "(op +)"}}.
+  somebody changes the definition of addition.
 
 
   The second document antiquotation we describe extends the first by a pattern
-  that specifies what the result of the ML-code should be and check the
+  that specifies what the result of the ML-code should be and checks the
   consistency of the actual result with the given pattern. For this we are
-  going to implement the document antiquotation
+  going to implement the document antiquotation:
 
   
   @{text [display] "@{ML_resp \"a_piece_of_code\" \"a_pattern\"}"}
   
   To add some convenience and also to deal with large outputs, the user can
-  give a partial specification inside the pattern by giving abbreviations of
-  the form @{text [quotes] "\<dots>"}. For example @{text "(\<dots>, \<dots>)"} for specifying a
-  pair.
-
-  In the document antiquotation @{text "@{ML_checked \"piece_of_code\"}"}
-  above we have sent the expression @{text [quotes] "val _ = piece_of_code"}
-  to the compiler, now instead the wildcard @{text "_"} we will be replaced by
-  the given pattern. To do this we need to replace in the input the @{text
-  [quotes] "\<dots>"} by @{text [quotes] "_"} before sending the code to the
-  compiler. The following function will do this:
+  give a partial specification by using ellipses. For example @{text "(\<dots>, \<dots>)"}
+  for specifying a pair.  In order to check consistency between the pattern
+  and the output of the code, we have to change the ML-expression that is sent 
+  to the compiler: in @{text "ML_checked"} we sent the expression @{text [quotes]
+  "val _ = a_piece_of_code"} to the compiler; now the wildcard @{text "_"}
+  must be be replaced by the given pattern. However, we have to remove all
+  ellipses from it and replace them by @{text [quotes] "_"}. The following 
+  function will do this:
 *}
 
 ML{*fun ml_pat (code_txt, pat) =
@@ -116,31 +117,34 @@
 end*}
 
 text {* 
-  Next we like to add a response indicator to the result using:
+  Next we add a response indicator to the result using:
 *}
 
 
 ML{*fun add_resp pat = map (fn s => "> " ^ s) pat*}
 
 text {* 
-  The rest of the code of the document antiquotation is
+  The rest of the code of @{text "ML_resp"} is: 
 *}
 
-ML{*fun output_ml_resp {context = ctxt, ...} ((code_txt, pat), pos) = 
+ML %linenosgray{*fun output_ml_resp {context = ctxt, ...} ((code_txt, pat), pos) = 
   (ML_Context.eval_in (SOME ctxt) false pos (ml_pat (code_txt, pat));
    let 
-     val output1 = space_explode "\n" code_txt 
-     val output2 = add_resp (space_explode "\n" pat)
+     val code_output = space_explode "\n" code_txt 
+     val resp_output = add_resp (space_explode "\n" pat)
    in 
-     ThyOutput.output (map Pretty.str (output1 @ output2)) 
+     ThyOutput.output (map Pretty.str (code_output @ resp_output)) 
    end)
 
 val _ = ThyOutput.antiquotation "ML_resp" 
-         (Scan.lift (OuterParse.position (Args.name -- Args.name))) 
-           output_ml_resp*}
+          (Scan.lift (OuterParse.position (Args.name -- Args.name))) 
+             output_ml_resp*}
 
 text {*
-  This extended document antiquotation allows us to write
+  In comparison with @{text "ML_checked"}, we only changed the line about 
+  the compiler (Line~2), the lines about
+  the output (Lines 4 to 7) and the parser in the setup (Line 11). Now 
+  you can write
  
   @{text [display] "@{ML_resp [display] \"true andalso false\" \"false\"}"}