doc/misc.tex: Document some more miscellaneous utilities.

[sod] / doc / parsing.tex

diff --git a/doc/parsing.tex b/doc/parsing.tex
index 28a747b..8aeb26b 100644 (file)
--- a/doc/parsing.tex
+++ b/doc/parsing.tex
@@ -43,6 +43,13 @@ consumed any input items.
 \begin{describe}{fun}{combine-parser-failures @<failures> @> @<list>}
 \end{describe}
 
 \begin{describe}{fun}{combine-parser-failures @<failures> @> @<list>}
 \end{describe}
 

+\begin{describe}{fun}{parse-empty \&optional @<value> @> @<function>}
+\end{describe}
+
+\begin{describe}{fun}
+    {parse-fail @<indicator> \&optional @<consumedp> @> @<function>}
+\end{describe}
+

 %%%--------------------------------------------------------------------------
 \section{File locations} \label{sec:parsing.floc}
 
 %%%--------------------------------------------------------------------------
 \section{File locations} \label{sec:parsing.floc}
 


@@ -64,51 +71,69 @@ consumed any input items.
 \end{describe*}
 
 \begin{describe}{gf}{file-location @<object> @> @<floc>}
 \end{describe*}
 
 \begin{describe}{gf}{file-location @<object> @> @<floc>}

-  \begin{describe}{meth}{file-location (@<floc> file-location) @> @<floc>}
+  \begin{describe}{meth}{file-location}
+      {file-location (@<floc> file-location) @> @<floc>}

   \end{describe}
   \end{describe}

-  \begin{describe}{meth}{file-location (@<stream> stream) @> @<floc>}
+  \begin{describe}{meth}{stream}
+      {file-location (@<stream> stream) @> @<floc>}

   \end{describe}
   \end{describe}

-  \begin{describe}{meth}{file-location (@<any> t) @> @<floc>}
+  \begin{describe}{meth}{t}
+      {file-location (@<any> t) @> @<floc>}

   \end{describe}
 \end{describe}
 
 \begin{describe}{cls}{condition-with-location (condition) \&key :location}
 \end{describe}
 
   \end{describe}
 \end{describe}
 
 \begin{describe}{cls}{condition-with-location (condition) \&key :location}
 \end{describe}
 

-\begin{describe}{meth}
+\begin{describe}{meth}{condition-with-location}

     {file-location (@<condition> condition-with-location) @> @<floc>}
 \end{describe}
 
 \begin{describe*}
     {\quad\=\quad\=\kill
      \dhead{cls}
     {file-location (@<condition> condition-with-location) @> @<floc>}
 \end{describe}
 
 \begin{describe*}
     {\quad\=\quad\=\kill
      \dhead{cls}

-      {error-with-location (condition-with-location error) \\ \>
-        \&key :location}
-    \dhead{cls}
-      {warning-with-location (condition-with-location warning) \\ \>
-        \&key :location}
-    \dhead{cls}
-      {enclosing-error-with-location
-          (enclosing-error-with-location error) \\ \>
-        \&key :condition :location}
-    \dhead{cls}
-      {enclosing-warning-with-location
-          (enclosing-condition-with-location warning) \\ \>
-        \&key :condition :location}
+       {error-with-location (condition-with-location error)     \\ \>
+         \&key :location}
+     \dhead{cls}
+       {warning-with-location (condition-with-location warning) \\ \>
+         \&key :location}
+     \dhead{cls}
+       {information-with-location (condition-with-location information) \\ \>
+         \&key :location}
+     \dhead{cls}
+       {enclosing-error-with-location
+           (enclosing-error-with-location error)                \\ \>
+         \&key :condition :location}
+     \dhead{cls}
+       {enclosing-warning-with-location
+           (enclosing-condition-with-location warning)          \\ \>
+         \&key :condition :location}
+     \dhead{cls}
+       {enclosing-information-with-location
+           (enclosing-condition-with-location information)      \\ \>
+         \&key :condition :location}
+     \dhead{cls}
+       {simple-condition-with-location
+           (condition-with-location simple-condition)           \\ \>
+         \&key :format-control :format-arguments :location}

      \dhead{cls}
      \dhead{cls}

-      {simple-condition-with-location
-          (condition-with-location simple-condition) \\ \>
-        \&key :format-control :format-arguments :location}
+       {simple-error-with-location
+           (error-with-location simple-error)                   \\ \>
+         \&key :format-control :format-arguments :location}

      \dhead{cls}
      \dhead{cls}

-      {simple-error-with-location
-          (error-with-location simple-error) \\ \>
-        \&key :format-control :format-arguments :location}
-    \dhead{cls}
-      {simple-warning-with-location
-          (warning-with-location simple-warning) \\ \>
-        \&key :format-control :format-arguments :location}}
+       {simple-warning-with-location
+           (warning-with-location simple-warning)               \\ \>
+         \&key :format-control :format-arguments :location}
+     \dhead{cls}
+       {simple-information-with-location
+           (information-with-location simple-information)       \\ \>
+         \&key :format-control :format-arguments :location}}

 \end{describe*}
 
 \end{describe*}
 

+\begin{describe}{gf}
+    {enclosing-condition-with-location-type @<condition> @> @<symbol>}
+\end{describe}
+

 \begin{describe}{fun}
     {make-condition-with-location @<default-type> @<floc>
                                   @<datum> \&rest @<arguments>
 \begin{describe}{fun}
     {make-condition-with-location @<default-type> @<floc>
                                   @<datum> \&rest @<arguments>


@@ -123,11 +148,52 @@ consumed any input items.
      \dhead{fun}{warn-with-location @<floc> @<datum> \&rest @<arguments>}}
 \end{describe*}
 
      \dhead{fun}{warn-with-location @<floc> @<datum> \&rest @<arguments>}}
 \end{describe*}
 

+\begin{describe*}
+    {\dhead{cls}{parser-error (error) \\ \ind
+                    \&key :expected :found \-}
+     \dhead{gf}{parser-error-expected @<condition> @> @<list>}
+     \dhead{gf}{parser-error-found @<condition> @> @<value>}}
+\end{describe*}
+
+\begin{describe}{fun}
+    {report-parser-error @<error> @<stream> @<show-expected> @<show-found>}
+\end{describe}
+
+\begin{describe*}
+    {\quad\=\kill
+     \dhead{cls}{base-lexer-error (error-with-location) \&key :location}
+     \dhead{cls}{simple-lexer-error
+                      (base-lexer-error simple-error-with-location) \\\>
+                    \&key :format-control :format-arguments :location}
+     \dhead{cls}{base-syntax-error (error-with-location) \&key :location}
+     \dhead{cls}{simple-syntax-error
+                      (base-syntax-error simple-error-with-location) \\\>
+                    \&key :format-control :format-arguments :location}}
+\end{describe*}
+

 \begin{describe}{mac}
     {with-default-error-location (@<floc>) @<declaration>^* @<form>^*
       @> @<value>^*}
 \end{describe}
 
 \begin{describe}{mac}
     {with-default-error-location (@<floc>) @<declaration>^* @<form>^*
       @> @<value>^*}
 \end{describe}
 

+\begin{describe}{gf}{classify-condition @<condition> @> @<string>}
+  \begin{describe*}
+      {\dhead{meth}{error}
+         {classify-condition (@<condition> error) @> @<string>}
+       \dhead{meth}{warning}
+         {classify-condition (@<condition> warning) @> @<string>}
+       \dhead{meth}{information}
+         {classify-condition (@<condition> information)
+             @> @<string>}
+       \dhead{meth}{base-lexer-error}
+         {classify-condition (@<condition> base-lexer-error)
+             @> @<string>}
+       \dhead{meth}{base-syntax-error}
+         {classify-condition (@<condition> base-syntax-error)
+             @> @<string>}}
+  \end{describe*}
+\end{describe}
+

 \begin{describe}{mac}
     {count-and-report-errors () @<declaration>^* @<form>^*
       @> @<value> @<n-errors> @<n-warnings>}
 \begin{describe}{mac}
     {count-and-report-errors () @<declaration>^* @<form>^*
       @> @<value> @<n-errors> @<n-warnings>}


@@ -183,7 +249,7 @@ depends on the type of scanner.  Given a captured place, the scanner can be
 rewound to the position held in it.
 
 Depending on how the scanner works, holding onto a captured place might
 rewound to the position held in it.
 
 Depending on how the scanner works, holding onto a captured place might

-consume a lot of memory or case poor performance.  For example, if the
+consume a lot of memory or cause poor performance.  For example, if the

 scanner is reading from an input stream, having a captured place means that
 data from that point on must be buffered in case the program needs to rewind
 the scanner and read that data again.  Therefore it's possible to
 scanner is reading from an input stream, having a captured place means that
 data from that point on must be buffered in case the program needs to rewind
 the scanner and read that data again.  Therefore it's possible to


@@ -212,10 +278,10 @@ the scanner and read that data again.  Therefore it's possible to
 \begin{describe}{mac}
     {with-scanner-place (@<place> @<scanner>) @<declarations>^* @<form>^*
       @> @<value>^*}
 \begin{describe}{mac}
     {with-scanner-place (@<place> @<scanner>) @<declarations>^* @<form>^*
       @> @<value>^*}

-  Capture the @<scanner>'s current position as a place, evaluate the
-  @<body-form>s as an implicit progn with the variable @<place> bound to the captured
-  place.  When control leaves the @<body-form>s, the place is released.  The return
-  values are the values of the final @<body-form>.
+  Capture the @<scanner>'s current position as a place, evaluate the @<form>s
+  as an implicit progn with the variable @<place> bound to the captured
+  place.  When control leaves the @<form>s, the place is released.  The
+  return values are the values of the final @<form>.

 \end{describe}
 
 \subsection{Scanner file-location protocol} \label{sec:parsing.scanner.floc}
 \end{describe}
 
 \subsection{Scanner file-location protocol} \label{sec:parsing.scanner.floc}


@@ -269,7 +335,7 @@ Character scanners are scanners which read sequences of characters.
 \begin{describe}{gf}{scanner-unread @<scanner> @<character>}
   Rewind the @<scanner> by one step.  The @<chararacter> must be the previous
   current character, and becomes the current character again.  It is an error
 \begin{describe}{gf}{scanner-unread @<scanner> @<character>}
   Rewind the @<scanner> by one step.  The @<chararacter> must be the previous
   current character, and becomes the current character again.  It is an error

-  if: the @<scanner> has reached end-of-file; the @<scanner> is never been
+  if: the @<scanner> has reached end-of-file; the @<scanner> has never been

   stepped; or @<character> was not the previous current character.
 \end{describe}
 
   stepped; or @<character> was not the previous current character.
 \end{describe}
 


@@ -363,15 +429,15 @@ file-location protocols.
 
 \begin{describe}{gf}
     {charbuf-scanner-map @<scanner> @<func> \&optional @<fail>
 
 \begin{describe}{gf}
     {charbuf-scanner-map @<scanner> @<func> \&optional @<fail>

-      \nlret @<result> @<successp> @<consumedp>}
+      \nlret @<result> @<success-flag> @<consumed-flag>}

   Read characters from the @<scanner>'s buffers.
 
   This is intended to be an efficient and versatile interface for reading
   characters from a scanner in bulk.  The function @<func> is invoked
   repeatedly, as if by
   \begin{prog}
   Read characters from the @<scanner>'s buffers.
 
   This is intended to be an efficient and versatile interface for reading
   characters from a scanner in bulk.  The function @<func> is invoked
   repeatedly, as if by
   \begin{prog}

-    (multiple-value-bind (@<donep> @<used>) \\ \ind\ind
-        (funcall @<func> @<buf> @<start> @<end>) \- \\
+    (multiple-value-bind (@<donep> @<used>)                     \\ \ind\ind
+        (funcall @<func> @<buf> @<start> @<end>)              \-\\

       \textrm\ldots)
   \end{prog}
   The argument @<buf> is a simple string; @<start> and @<end> are two
       \textrm\ldots)
   \end{prog}
   The argument @<buf> is a simple string; @<start> and @<end> are two


@@ -379,7 +445,7 @@ file-location protocols.
   @<start> (inclusive) and @<end> (exclusive) should be processed.  If
   @<func>'s return value @<donep> is nil then @<used> is ignored: the
   function has consumed the entire buffer and wishes to read more.  If
   @<start> (inclusive) and @<end> (exclusive) should be processed.  If
   @<func>'s return value @<donep> is nil then @<used> is ignored: the
   function has consumed the entire buffer and wishes to read more.  If

-  @<donep> is non-nil, then it must be a fixnum such that $@<start> \le
+  @<donep> is non-nil, then @<used> must be a fixnum such that $@<start> \le

   @<used> \le @<end>$: the function has consumed the buffer as far as @<used>
   (exclusive) and has completed successfully.
 
   @<used> \le @<end>$: the function has consumed the buffer as far as @<used>
   (exclusive) and has completed successfully.
 


@@ -387,8 +453,8 @@ file-location protocols.
   fails: the @<fail> function is called with no arguments, and is expected to
   return two values.  If omitted, @<fail> defaults to
   \begin{prog}
   fails: the @<fail> function is called with no arguments, and is expected to
   return two values.  If omitted, @<fail> defaults to
   \begin{prog}

-    (lambda () \\ \ind
-      (values nil nil))%
+    (lambda ()                                                  \\ \ind
+      (values nil nil))

   \end{prog}
 
   The @|charbuf-scanner-map| function returns three values.  The first value
   \end{prog}
 
   The @|charbuf-scanner-map| function returns three values.  The first value


@@ -447,18 +513,18 @@ file-location protocols.
 
 \begin{describe}{mac}
     {defparse @<name> (@[[ :context (@<var> @<context-class>) @]]
 
 \begin{describe}{mac}
     {defparse @<name> (@[[ :context (@<var> @<context-class>) @]]

-                       @<destructuring-lambda-list-item>^*) \\ \ind
-      @[[ @<declaration>^* @! @<doc-string> @]] \\
-      @<form>^* \-
-     \nlret @<name>}
+                       @<destructuring-lambda-list-item>^*)     \\ \ind
+      @[[ @<declaration>^* @! @<doc-string> @]]                 \\
+      @<form>^*
+     \-\nlret @<name>}

 \end{describe}
 
 \begin{describe}{mac}
     {with-parser-context
 \end{describe}
 
 \begin{describe}{mac}
     {with-parser-context

-        (@<context-class> @{ @<init-keyword> @<value> @}^*) \\ \ind
-      @<declaration>^* \\
-      @<form>^* \-
-     \nlret @<value>^*}
+        (@<context-class> @{ @<init-keyword> @<value> @}^*)     \\ \ind
+      @<declaration>^*                                          \\
+      @<form>^*
+     \-\nlret @<value>^*}

 \end{describe}
 
 \begin{describe}{lmac}
 \end{describe}
 
 \begin{describe}{lmac}


@@ -478,31 +544,28 @@ file-location protocols.
 \begin{describe}{gf}{parser-step @<context> @> @<form>}
 \end{describe}
 
 \begin{describe}{gf}{parser-step @<context> @> @<form>}
 \end{describe}
 

-\begin{describe}{sym}{it}
-\end{describe}
-

 \begin{describe}{mac}
     {if-parse (@[[ \=:result @<result-var> @!
 \begin{describe}{mac}
     {if-parse (@[[ \=:result @<result-var> @!

-                     :expected @<expected-var> @! \+ \\
-                     :consumedp @<consumed-var> @]]) \- \\ \ind\ind
-        @<parser> \- \\
-      @<consequent> \\
-      @[@<alternatve>@] \-
-     \nlret @<value>^*}
+                     :expected @<expected-var> @!             \+\\
+                     :consumedp @<consumed-var> @]])          \-\\ \ind\ind
+        @<parser>                                             \-\\
+      @<consequent>                                             \\
+      @[@<alternatve>@]
+     \-\nlret @<value>^*}

 \end{describe}
 
 \begin{describe}{mac}
 \end{describe}
 
 \begin{describe}{mac}

-    {when-parse (@[@<result-var>@]) @<parser> \\ \ind
-      @<form>^* \-
-     \nlret @<value>^*}
+    {when-parse (@[@<result-var>@]) @<parser>                   \\ \ind
+      @<form>^*
+     \-\nlret @<value>^*}

 \end{describe}
 
 \begin{describe}{mac}
     {cond-parse (@[[ \=:result @<result-var> @!
 \end{describe}
 
 \begin{describe}{mac}
     {cond-parse (@[[ \=:result @<result-var> @!

-                       :expected @<expected-var> @! \+ \\
-                       :consumedp @<consumed-var> @]]) \- \\ \ind
-      @{ (@<parser> @<form>^*) @}^* \-
-     \nlret @<value>^*}
+                       :expected @<expected-var> @!           \+\\
+                       :consumedp @<consumed-var> @]])        \-\\ \ind
+      @{ (@<parser> @<form>^*) @}^*
+     \-\nlret @<value>^*}

 \end{describe}
 
 \begin{describe}{parse}{:eof}
 \end{describe}
 
 \begin{describe}{parse}{:eof}


@@ -530,8 +593,9 @@ file-location protocols.
 \end{describe}
 
 \begin{describe}{parseform}
 \end{describe}
 
 \begin{describe}{parseform}

-    {seq (@{ @<atomic-parser-spec> @! (@[@<var>@] @<parser>) @}^*) \\ \ind
-      @<body-form>^*}
+    {seq (@{ @<atomic-parser-spec> @!
+             (@[@<var>@] @<parser>) @}^*)                       \\ \ind
+      @<form>^*}

 \end{describe}
 
 \begin{describe}{parseform}{and @<parser>^*}
 \end{describe}
 
 \begin{describe}{parseform}{and @<parser>^*}


@@ -544,22 +608,22 @@ file-location protocols.
 \end{describe}
 
 \begin{describe}{parseform}
 \end{describe}
 
 \begin{describe}{parseform}

-    {many (\=@<accumulator-var> @<init-form> @<update-form> \+ \\
-           @[[ \=:new @<new-var> @! :final @<final-form> @! \+ \\
-                 :min @<minimum> @! :max @<maximum> @! \\
-                 :commitp @<commitp> @]]) \-\- \\ \ind
+    {many (\=@<accumulator-var> @<init-form> @<update-form>   \+\\
+           @[[ \=:new @<new-var> @! :final @<final-form> @!   \+\\
+                 :min @<minimum> @! :max @<maximum> @!          \\
+                 :commitp @<commitp> @]])                   \-\-\\ \ind

       @<item-parser> @[@<sep-parser>@]}
 \end{describe}
 
 \begin{describe}{parseform}
     {list (@[[ :min @<minimum> @! :max @<maximum> @!
       @<item-parser> @[@<sep-parser>@]}
 \end{describe}
 
 \begin{describe}{parseform}
     {list (@[[ :min @<minimum> @! :max @<maximum> @!

-               :commitp @<commitp> @]])\\ \ind
+               :commitp @<commitp> @]])                         \\ \ind

       @<item-parser> @[@<sep-parser>@]}
 \end{describe}
 
 \begin{describe}{parseform}
     {skip-many (@[[ :min @<minimum> @! :max @<maximum> @!
       @<item-parser> @[@<sep-parser>@]}
 \end{describe}
 
 \begin{describe}{parseform}
     {skip-many (@[[ :min @<minimum> @! :max @<maximum> @!

-                    :commitp @<commitp> @]])\\ \ind
+                    :commitp @<commitp> @]])                    \\ \ind

       @<item-parser> @[@<sep-parser>@]}
 \end{describe}
 
       @<item-parser> @[@<sep-parser>@]}
 \end{describe}
 


@@ -589,7 +653,7 @@ file-location protocols.
 \end{describe}
 
 \begin{describe}{gf}
 \end{describe}
 
 \begin{describe}{gf}

-    {parser-places-must-be-released-p @<context> @> @<generalized-boolean>>}
+    {parser-places-must-be-released-p @<context> @> @<generalized-boolean>}

 \end{describe}
 
 \begin{describe}{mac}
 \end{describe}
 
 \begin{describe}{mac}


@@ -601,6 +665,9 @@ file-location protocols.
 \begin{describe}{parseform}{peek @<parser>}
 \end{describe}
 
 \begin{describe}{parseform}{peek @<parser>}
 \end{describe}
 

+\begin{describe}{parseform}{commit}
+\end{describe}
+

 \begin{describe}{cls}{character-parser-context () \&key}
 \end{describe}
 
 \begin{describe}{cls}{character-parser-context () \&key}
 \end{describe}
 


@@ -614,10 +681,10 @@ file-location protocols.
 \begin{describe}{parseform}{char @<character>}
 \end{describe}
 
 \begin{describe}{parseform}{char @<character>}
 \end{describe}
 

-\begin{describe}[char]{parse}{@<character>}
+\begin{describe}{parse}[char]{@<character>}

 \end{describe}
 
 \end{describe}
 

-\begin{describe}[string]{parse}{@<string>}
+\begin{describe}{parse}[string]{@<string>}

 \end{describe}
 
 \begin{describe}{parse}{:any}
 \end{describe}
 
 \begin{describe}{parse}{:any}


@@ -647,10 +714,7 @@ file-location protocols.
 \begin{describe}{parseform}{token @<type> @[@<value>@] @[:peekp @<peek>@]}
 \end{describe}
 
 \begin{describe}{parseform}{token @<type> @[@<value>@] @[:peekp @<peek>@]}
 \end{describe}
 

-\begin{describe}[atom]{parse}{@<atom>}
-\end{describe}
-
-\begin{describe}[string]{parse}{@<string>}
+\begin{describe}{parse}[atom]{@<atom>}

 \end{describe}
 
 \begin{describe}{cls}{scanner-context () \&key :scanner}
 \end{describe}
 
 \begin{describe}{cls}{scanner-context () \&key :scanner}


@@ -682,7 +746,7 @@ file-location protocols.
 \end{describe}
 
 \begin{describe}{parseform}
 \end{describe}
 
 \begin{describe}{parseform}

-    {expr \=(@[[ :nestedp @<nestedp-var> @]]) \+ \\
+    {expr \=(@[[ :nestedp @<nestedp-var> @]])                 \+\\

             @<operand-parser> @<binop-parser>
             @<preop-parser> @<postop-parser>}
 \end{describe}
             @<operand-parser> @<binop-parser>
             @<preop-parser> @<postop-parser>}
 \end{describe}


@@ -708,12 +772,13 @@ file-location protocols.
 
 \begin{describe*}
     {\quad\=\kill
 
 \begin{describe*}
     {\quad\=\kill

-     \dhead{cls}{simple-binary-operator (simple-operator) \\ \>
-                  \&key :name :function :lprec :rprec :associativity}
+     \dhead{cls}{simple-binary-operator (simple-operator)       \\ \>
+                  \&key :name :function
+                        :lprec :rprec :associativity}

      \dhead{cls}{simple-postfix-operator (simple-unary-operator) \\ \>
                   \&key :name :function :lprec :rprec}
      \dhead{cls}{simple-prefix-operator
      \dhead{cls}{simple-postfix-operator (simple-unary-operator) \\ \>
                   \&key :name :function :lprec :rprec}
      \dhead{cls}{simple-prefix-operator

-                    (prefix-operator simple-unary-operator) \\ \>
+                    (prefix-operator simple-unary-operator)     \\ \>

                   \&key :name :function :rprec}}
 \end{describe*}
 
                   \&key :name :function :rprec}}
 \end{describe*}
 


@@ -752,18 +817,34 @@ file-location protocols.
 \begin{describe}{fun}{define-indicator @<indicator> @<description>}
 \end{describe}
 
 \begin{describe}{fun}{define-indicator @<indicator> @<description>}
 \end{describe}
 

-\begin{describe}{fun}{syntax-error @<scanner> @<expected> \&key :continuep}
+\begin{describe*}
+    {\dhead{cls}{lexer-error (parser-error base-lexer-error) \\ \ind
+                    \&key :expected :found :location \-}
+     \dhead{cls}{syntax-error (parser-error base-syntax-error) \\ \ind
+                    \&key :expected :found :location \-}}
+\end{describe*}
+
+\begin{describe}{fun}
+    {syntax-error @<scanner> @<expected> \&key :continuep :location}

 \end{describe}
 
 \begin{describe}{fun}
 \end{describe}
 
 \begin{describe}{fun}

-    {lexer-error @<char-scanner> @<expected> @<consumed-flag>}
+    {lexer-error @<char-scanner> @<expected> \&key :location}

 \end{describe}
 
 \begin{describe}{parseform}
     {skip-until (@[[ :keep-end @<keep-end-flag> @]]) @<token-type>^*}
 \end{describe}
 
 \end{describe}
 
 \begin{describe}{parseform}
     {skip-until (@[[ :keep-end @<keep-end-flag> @]]) @<token-type>^*}
 \end{describe}
 

-\begin{describe}{parseform}{error () @<sub-parser> @<recover-parser>}
+\begin{describe}{parseform}
+    {error (@[[ :ignore-unconsumed @<flag> @!
+                :force-process @<flag> @]])                     \\ \ind\ind
+        @<sub-parser> @<recover-parser>                       \-\\
+      @<declaration>^*                                          \\
+      @<form>^*}
+\end{describe}
+
+\begin{describe}{parseform}{must @<sub-parser> @[@<default>@]}

 \end{describe}
 
 \begin{describe}{fun}
 \end{describe}
 
 \begin{describe}{fun}