diff -r 8939b8fd8603 -r 069d525f8f1d CookBook/Recipes/Antiquotes.thy --- a/CookBook/Recipes/Antiquotes.thy Wed Mar 18 23:52:51 2009 +0100 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,165 +0,0 @@ - -theory Antiquotes -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 - - 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 - - @{ML [display,gray] "ThyOutput.print_antiquotations ()"} - - 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. - - We first describe the antiquotation @{text "ML_checked"} with the syntax: - - @{text [display] "@{ML_checked \"a_piece_of_code\"}"} - - The code is checked by sending the ML-expression @{text [quotes] "val _ = - a_piece_of_code"} to the ML-compiler (i.e.~the function @{ML - "ML_Context.eval_in"} in Line 4 below). The complete code of the - document antiquotation is as follows: - -*} - -ML%linenosgray{*fun ml_val code_txt = "val _ = " ^ code_txt - -fun output_ml {context = ctxt, ...} code_txt = - (ML_Context.eval_in (SOME ctxt) false Position.none (ml_val code_txt); - ThyOutput.output (map Pretty.str (space_explode "\n" code_txt))) - -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. - - - \begin{readmore} - For more information about options of document antiquotations see \rsccite{sec:antiq}). - \end{readmore} - - Since we used the argument @{ML "Position.none"}, the compiler cannot give specific - information about the line number, in case an error is detected. We - can improve the code above slightly by writing -*} - -ML%linenosgray{*fun output_ml {context = ctxt, ...} (code_txt, pos) = - (ML_Context.eval_in (SOME ctxt) false pos (ml_val code_txt); - ThyOutput.output (map Pretty.str (space_explode "\n" code_txt))) - -val _ = ThyOutput.antiquotation "ML_checked" - (Scan.lift (OuterParse.position Args.name)) output_ml *} - -text {* - where in Lines 1 and 2 the positional information is properly treated. The - 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 - obtain @{ML_checked "2 + 3"} and be sure that this code compiles until - somebody changes the definition of \mbox{@{ML "(op +)"}}. - - - 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 - consistency of the actual result with the given pattern. For this we are - 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] "\"}. For example @{text "(\, \)"} 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] "\"} by @{text [quotes] "_"} before sending the code to the - compiler. The following function will do this: -*} - -ML{*fun ml_pat (code_txt, pat) = -let val pat' = - implode (map (fn "\" => "_" | s => s) (Symbol.explode pat)) -in - "val " ^ pat' ^ " = " ^ code_txt -end*} - -text {* - Next we like to 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 -*} - -ML{*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) - in - ThyOutput.output (map Pretty.str (output1 @ output2)) - end) - -val _ = ThyOutput.antiquotation "ML_resp" - (Scan.lift (OuterParse.position (Args.name -- Args.name))) - output_ml_resp*} - -text {* - This extended document antiquotation allows us to write - - @{text [display] "@{ML_resp [display] \"true andalso false\" \"false\"}"} - - to obtain - - @{ML_resp [display] "true andalso false" "false"} - - or - - @{text [display] "@{ML_resp [display] \"let val i = 3 in (i * i, \"foo\") end\" \"(9, \)\"}"} - - to obtain - - @{ML_resp [display] "let val i = 3 in (i * i, \"foo\") end" "(9, \)"} - - In both cases, the check by the compiler ensures that code and result - match. A limitation of this document antiquotation, however, is that the - pattern can only be given for values that can be constructed. This excludes - values that are abstract datatypes, like @{ML_type thm}s and @{ML_type cterm}s. - -*} -end \ No newline at end of file