--- a/ProgTutorial/Parsing.thy Sun Oct 11 22:45:29 2009 +0200
+++ b/ProgTutorial/Parsing.thy Sun Oct 11 23:16:34 2009 +0200
@@ -37,7 +37,7 @@
text {*
Let us first have a look at parsing strings using generic parsing
- combinators. The function @{ML_ind "$$"} takes a string as argument and will
+ combinators. The function @{ML_ind "$$" in Scan} takes a string as argument and will
``consume'' this string from a given input list of strings. ``Consume'' in
this context means that it will return a pair consisting of this string and
the rest of the input list. For example:
@@ -71,11 +71,12 @@
However, note that these exceptions are private to the parser and cannot be accessed
by the programmer (for example to handle them).
- In the examples above we use the function @{ML_ind Symbol.explode}, instead of the
- more standard library function @{ML_ind explode}, for obtaining an input list for
- the parser. The reason is that @{ML_ind Symbol.explode} is aware of character sequences,
- for example @{text "\<foo>"}, that have a special meaning in Isabelle. To see
- the difference consider
+ In the examples above we use the function @{ML_ind explode in Symbol} in the
+ structure @{ML_struct Symbol}, instead of the more standard library function
+ @{ML_ind explode}, for obtaining an input list for the parser. The reason is
+ that @{ML_ind explode} in @{ML_struct Symbol} is aware of character
+ sequences, for example @{text "\<foo>"}, that have a special meaning in
+ Isabelle. To see the difference consider
@{ML_response_fake [display,gray]
"let
@@ -87,7 +88,7 @@
[\"\<foo>\", \" \", \"b\", \"a\", \"r\"])"}
Slightly more general than the parser @{ML "$$"} is the function
- @{ML_ind one in Scan}, in that it takes a predicate as argument and
+ @{ML_ind one in Scan}, in that it takes a predicate as argument and
then parses exactly
one item from the input list satisfying this predicate. For example the
following parser either consumes an @{text [quotes] "h"} or a @{text
@@ -103,7 +104,7 @@
end"
"((\"h\", [\"e\", \"l\", \"l\", \"o\"]),(\"w\", [\"o\", \"r\", \"l\", \"d\"]))"}
- Two parsers can be connected in sequence by using the function @{ML_ind "--"}.
+ Two parsers can be connected in sequence by using the function @{ML_ind "--" in Scan}.
For example parsing @{text "h"}, @{text "e"} and @{text "l"} (in this
order) you can achieve by:
@@ -121,7 +122,7 @@
"(\"hell\", [\"o\"])"}
Parsers that explore alternatives can be constructed using the function
- @{ML_ind "||"}. The parser @{ML "(p || q)" for p q} returns the
+ @{ML_ind "||" in Scan}. The parser @{ML "(p || q)" for p q} returns the
result of @{text "p"}, in case it succeeds, otherwise it returns the
result of @{text "q"}. For example:
@@ -136,7 +137,7 @@
end"
"((\"h\", [\"e\", \"l\", \"l\", \"o\"]), (\"w\", [\"o\", \"r\", \"l\", \"d\"]))"}
- The functions @{ML_ind "|--"} and @{ML_ind "--|"} work like the sequencing
+ The functions @{ML_ind "|--" in Scan} and @{ML_ind "--|" in Scan} work like the sequencing
function for parsers, except that they discard the item being parsed by the
first (respectively second) parser. For example:
@@ -164,7 +165,7 @@
end"
"((\"h\", [\"e\", \"l\", \"l\", \"o\"]), (\"x\", [\"w\", \"o\", \"r\", \"l\", \"d\"]))"}
- The function @{ML_ind option in Scan} works similarly, except no default value can
+ The function @{ML_ind option in Scan} works similarly, except no default value can
be given. Instead, the result is wrapped as an @{text "option"}-type. For example:
@{ML_response [display,gray]
@@ -176,14 +177,14 @@
(p input1, p input2)
end" "((SOME \"h\", [\"e\", \"l\", \"l\", \"o\"]), (NONE, [\"w\", \"o\", \"r\", \"l\", \"d\"]))"}
- The function @{ML_ind ahead in Scan} parses some input, but leaves the original
+ The function @{ML_ind ahead in Scan} parses some input, but leaves the original
input unchanged. For example:
@{ML_response [display,gray]
"Scan.ahead (Scan.this_string \"foo\") (Symbol.explode \"foo\")"
"(\"foo\", [\"f\", \"o\", \"o\"])"}
- The function @{ML_ind "!!"} helps with producing appropriate error messages
+ The function @{ML_ind "!!" in Scan} helps with producing appropriate error messages
during parsing. For example if you want to parse @{text p} immediately
followed by @{text q}, or start a completely different parser @{text r},
you might write:
@@ -219,13 +220,13 @@
then the parsing aborts and the error message @{text "foo"} is printed. In order to
see the error message properly, you need to prefix the parser with the function
- @{ML_ind error in Scan}. For example:
+ @{ML_ind error in Scan}. For example:
@{ML_response_fake [display,gray]
"Scan.error (!! (fn _ => \"foo\") ($$ \"h\"))"
"Exception Error \"foo\" raised"}
- This ``prefixing'' is usually done by wrappers such as @{ML_ind local_theory in OuterSyntax}
+ This ``prefixing'' is usually done by wrappers such as @{ML_ind local_theory in OuterSyntax}
(see Section~\ref{sec:newcommand} which explains this function in more detail).
Let us now return to our example of parsing @{ML "(p -- q) || r" for p q
@@ -262,14 +263,14 @@
@{ML_response [display,gray] "Scan.repeat ($$ \"h\") (Symbol.explode \"hhhhello\")"
"([\"h\", \"h\", \"h\", \"h\"], [\"e\", \"l\", \"l\", \"o\"])"}
- Note that @{ML_ind repeat in Scan} stores the parsed items in a list. The function
- @{ML_ind repeat1 in Scan} is similar, but requires that the parser @{text "p"}
+ Note that @{ML_ind repeat in Scan} stores the parsed items in a list. The function
+ @{ML_ind repeat1 in Scan} is similar, but requires that the parser @{text "p"}
succeeds at least once.
Also note that the parser would have aborted with the exception @{text MORE}, if
you had it run with the string @{text [quotes] "hhhh"}. This can be avoided by using
- the wrapper @{ML_ind finite in Scan} and the ``stopper-token''
- @{ML_ind stopper in Symbol}. With them you can write:
+ the wrapper @{ML_ind finite in Scan} and the ``stopper-token''
+ @{ML_ind stopper in Symbol}. With them you can write:
@{ML_response [display,gray] "Scan.finite Symbol.stopper (Scan.repeat ($$ \"h\")) (Symbol.explode \"hhhh\")"
"([\"h\", \"h\", \"h\", \"h\"], [])"}
@@ -278,7 +279,7 @@
other stoppers need to be used when parsing, for example, tokens. However, this kind of
manually wrapping is often already done by the surrounding infrastructure.
- The function @{ML_ind repeat in Scan} can be used with @{ML_ind one in Scan} to read any
+ The function @{ML_ind repeat in Scan} can be used with @{ML_ind one in Scan} to read any
string as in
@{ML_response [display,gray]
@@ -290,10 +291,10 @@
end"
"([\"f\", \"o\", \"o\", \" \", \"b\", \"a\", \"r\", \" \", \"f\", \"o\", \"o\"], [])"}
- where the function @{ML_ind not_eof in Symbol} ensures that we do not read beyond the
+ where the function @{ML_ind not_eof in Symbol} ensures that we do not read beyond the
end of the input string (i.e.~stopper symbol).
- The function @{ML_ind unless in Scan} takes two parsers: if the first one can
+ The function @{ML_ind unless in Scan} takes two parsers: if the first one can
parse the input, then the whole parser fails; if not, then the second is tried. Therefore
@{ML_response_fake_both [display,gray] "Scan.unless ($$ \"h\") ($$ \"w\") (Symbol.explode \"hello\")"
@@ -306,7 +307,7 @@
succeeds.
- The functions @{ML_ind repeat in Scan} and @{ML_ind unless in Scan} can
+ The functions @{ML_ind repeat in Scan} and @{ML_ind unless in Scan} can
be combined to read any input until a certain marker symbol is reached. In the
example below the marker symbol is a @{text [quotes] "*"}.
@@ -324,7 +325,7 @@
After parsing is done, you almost always want to apply a function to the parsed
- items. One way to do this is the function @{ML_ind ">>"} where
+ items. One way to do this is the function @{ML_ind ">>" in Scan} where
@{ML "(p >> f)" for p f} runs
first the parser @{text p} and upon successful completion applies the
function @{text f} to the result. For example
@@ -352,7 +353,7 @@
where the single-character strings in the parsed output are transformed
back into one string.
- The function @{ML_ind lift in Scan} takes a parser and a pair as arguments. This function applies
+ The function @{ML_ind lift in Scan} takes a parser and a pair as arguments. This function applies
the given parser to the second component of the pair and leaves the first component
untouched. For example
@@ -393,11 +394,11 @@
\end{readmore}
The structure @{ML_struct OuterLex} defines several kinds of tokens (for
- example @{ML_ind Ident in OuterLex} for identifiers, @{ML Keyword in
- OuterLex} for keywords and @{ML_ind Command in OuterLex} for commands). Some
+ example @{ML_ind Ident in OuterLex} for identifiers, @{ML Keyword in
+ OuterLex} for keywords and @{ML_ind Command in OuterLex} for commands). Some
token parsers take into account the kind of tokens. The first example shows
how to generate a token list out of a string using the function
- @{ML_ind scan in OuterSyntax}. It is given the argument
+ @{ML_ind scan in OuterSyntax}. It is given the argument
@{ML "Position.none"} since,
at the moment, we are not interested in generating precise error
messages. The following code\footnote{Note that because of a possible bug in
@@ -415,7 +416,7 @@
other syntactic category. The second indicates a space.
We can easily change what is recognised as a keyword with the function
- @{ML_ind keyword in OuterKeyword}. For example calling it with
+ @{ML_ind keyword in OuterKeyword}. For example calling it with
*}
ML{*val _ = OuterKeyword.keyword "hello"*}
@@ -430,7 +431,7 @@
Many parsing functions later on will require white space, comments and the like
to have already been filtered out. So from now on we are going to use the
- functions @{ML filter} and @{ML_ind is_proper in OuterLex} to do this.
+ functions @{ML filter} and @{ML_ind is_proper in OuterLex} to do this.
For example:
@{ML_response_fake [display,gray]
@@ -468,10 +469,10 @@
end"
"([\"}\", \"{\", \<dots>], [\"\<rightleftharpoons>\", \"\<leftharpoondown>\", \<dots>])"}
- You might have to adjust the @{ML_ind print_depth} in order to
+ You might have to adjust the @{ML_ind print_depth} in order to
see the complete list.
- The parser @{ML_ind "$$$" in OuterParse} parses a single keyword. For example:
+ The parser @{ML_ind "$$$" in OuterParse} parses a single keyword. For example:
@{ML_response [display,gray]
"let
@@ -482,7 +483,7 @@
end"
"((\"where\",\<dots>), (\"|\",\<dots>))"}
- Any non-keyword string can be parsed with the function @{ML_ind reserved in OuterParse}.
+ Any non-keyword string can be parsed with the function @{ML_ind reserved in OuterParse}.
For example:
@{ML_response [display,gray]
@@ -494,7 +495,7 @@
end"
"(\"bar\",[])"}
- Like before, you can sequentially connect parsers with @{ML_ind "--"}. For example:
+ Like before, you can sequentially connect parsers with @{ML "--"}. For example:
@{ML_response [display,gray]
"let
@@ -558,7 +559,7 @@
\begin{exercise} (FIXME)
A type-identifier, for example @{typ "'a"}, is a token of
- kind @{ML_ind Keyword in OuterLex}. It can be parsed using
+ kind @{ML_ind Keyword in OuterLex}. It can be parsed using
the function @{ML type_ident in OuterParse}.
\end{exercise}
@@ -739,7 +740,7 @@
variables with optional type-annotation and syntax-annotation, and a list of
rules where every rule has optionally a name and an attribute.
- The function @{ML_ind "fixes" in OuterParse} in Line 2 of the parser reads an
+ The function @{ML_ind "fixes" in OuterParse} in Line 2 of the parser reads an
\isacommand{and}-separated
list of variables that can include optional type annotations and syntax translations.
For example:\footnote{Note that in the code we need to write
@@ -763,8 +764,8 @@
not yet used to type the variables: this must be done by type-inference later
on. Since types are part of the inner syntax they are strings with some
encoded information (see previous section). If a mixfix-syntax is
- present for a variable, then it is stored in the @{ML_ind Mixfix} data structure;
- no syntax translation is indicated by @{ML_ind NoSyn}.
+ present for a variable, then it is stored in the @{ML_ind Mixfix} data structure;
+ no syntax translation is indicated by @{ML_ind NoSyn}.
\begin{readmore}
The data structure for mixfix annotations is defined in @{ML_file "Pure/Syntax/mixfix.ML"}.
@@ -773,7 +774,7 @@
Lines 3 to 7 in the function @{ML spec_parser} implement the parser for a
list of introduction rules, that is propositions with theorem annotations
such as rule names and attributes. The introduction rules are propositions
- parsed by @{ML_ind prop in OuterParse}. However, they can include an optional
+ parsed by @{ML_ind prop in OuterParse}. However, they can include an optional
theorem name plus some attributes. For example
@{ML_response [display,gray] "let
@@ -783,8 +784,8 @@
(name, map Args.dest_src attrib)
end" "(foo_lemma, [((\"intro\", []), \<dots>), ((\"dest\", [\<dots>]), \<dots>)])"}
- The function @{ML_ind opt_thm_name in SpecParse} is the ``optional'' variant of
- @{ML_ind thm_name in SpecParse}. Theorem names can contain attributes. The name
+ The function @{ML_ind opt_thm_name in SpecParse} is the ``optional'' variant of
+ @{ML_ind thm_name in SpecParse}. Theorem names can contain attributes. The name
has to end with @{text [quotes] ":"}---see the argument of
the function @{ML SpecParse.opt_thm_name} in Line 7.
@@ -799,7 +800,7 @@
Have a look at how the parser @{ML SpecParse.where_alt_specs} is implemented
in file @{ML_file "Pure/Isar/spec_parse.ML"}. This parser corresponds
to the ``where-part'' of the introduction rules given above. Below
- we paraphrase the code of @{ML_ind where_alt_specs in SpecParse} adapted to our
+ we paraphrase the code of @{ML_ind where_alt_specs in SpecParse} adapted to our
purposes.
\begin{isabelle}
*}
@@ -850,7 +851,7 @@
end *}
text {*
- The crucial function @{ML_ind local_theory in OuterSyntax} expects a name for the command, a
+ The crucial function @{ML_ind local_theory in OuterSyntax} expects a name for the command, a
short description, a kind indicator (which we will explain later more thoroughly) and a
parser producing a local theory transition (its purpose will also explained
later).
@@ -996,7 +997,7 @@
The crucial part of a command is the function that determines the behaviour
of the command. In the code above we used a ``do-nothing''-function, which
- because of @{ML_ind succeed in Scan} does not parse any argument, but immediately
+ because of @{ML_ind succeed in Scan} does not parse any argument, but immediately
returns the simple function @{ML "LocalTheory.theory I"}. We can
replace this code by a function that first parses a proposition (using the
parser @{ML OuterParse.prop}), then prints out the tracing
@@ -1022,7 +1023,7 @@
foobar_trace "True \<and> False"
text {*
- Note that so far we used @{ML_ind thy_decl in OuterKeyword} as the kind
+ Note that so far we used @{ML_ind thy_decl in OuterKeyword} as the kind
indicator for the command. This means that the command finishes as soon as
the arguments are processed. Examples of this kind of commands are
\isacommand{definition} and \isacommand{declare}. In other cases, commands
@@ -1030,7 +1031,7 @@
``open up'' a proof in order to prove the proposition (for example
\isacommand{lemma}) or prove some other properties (for example
\isacommand{function}). To achieve this kind of behaviour, you have to use
- the kind indicator @{ML_ind thy_goal in OuterKeyword} and the function @{ML
+ the kind indicator @{ML_ind thy_goal in OuterKeyword} and the function @{ML
"local_theory_to_proof" in OuterSyntax} to set up the command. Note,
however, once you change the ``kind'' of a command from @{ML thy_decl in
OuterKeyword} to @{ML thy_goal in OuterKeyword} then the keyword file needs
@@ -1059,8 +1060,8 @@
text {*
The function @{text goal_prop} in Lines 2 to 7 takes a string (the proposition to be
proved) and a context as argument. The context is necessary in order to be able to use
- @{ML_ind read_prop in Syntax}, which converts a string into a proper proposition.
- In Line 6 the function @{ML_ind theorem_i in Proof} starts the proof for the
+ @{ML_ind read_prop in Syntax}, which converts a string into a proper proposition.
+ In Line 6 the function @{ML_ind theorem_i in Proof} starts the proof for the
proposition. Its argument @{ML NONE} stands for a locale (which we chose to
omit); the argument @{ML "(K I)"} stands for a function that determines what
should be done with the theorem once it is proved (we chose to just forget
@@ -1085,7 +1086,7 @@
text {*
{\bf TBD below}
- (FIXME: read a name and show how to store theorems; see @{ML_ind note in LocalTheory})
+ (FIXME: read a name and show how to store theorems; see @{ML_ind note in LocalTheory})
*}
@@ -1266,7 +1267,7 @@
It defines the method @{text foo}, which takes no arguments (therefore the
parser @{ML Scan.succeed}) and only applies a single tactic, namely the tactic which
applies @{thm [source] conjE} and then @{thm [source] conjI}. The function
- @{ML_ind SIMPLE_METHOD}
+ @{ML_ind SIMPLE_METHOD in Method}
turns such a tactic into a method. The method @{text "foo"} can be used as follows
*}