(* $Id$ *)
theory Inner_Syntax
imports Main
begin
chapter {* Inner syntax --- the term language *}
section {* Printing logical entities *}
subsection {* Diagnostic commands *}
text {*
\begin{matharray}{rcl}
@{command_def "pr"}@{text "\<^sup>*"} & : & @{text "any \<rightarrow>"} \\
@{command_def "thm"}@{text "\<^sup>*"} & : & @{text "context \<rightarrow>"} \\
@{command_def "term"}@{text "\<^sup>*"} & : & @{text "context \<rightarrow>"} \\
@{command_def "prop"}@{text "\<^sup>*"} & : & @{text "context \<rightarrow>"} \\
@{command_def "typ"}@{text "\<^sup>*"} & : & @{text "context \<rightarrow>"} \\
@{command_def "prf"}@{text "\<^sup>*"} & : & @{text "context \<rightarrow>"} \\
@{command_def "full_prf"}@{text "\<^sup>*"} & : & @{text "context \<rightarrow>"} \\
\end{matharray}
These diagnostic commands assist interactive development by printing
internal logical entities in a human-readable fashion.
\begin{rail}
'pr' modes? nat? (',' nat)?
;
'thm' modes? thmrefs
;
'term' modes? term
;
'prop' modes? prop
;
'typ' modes? type
;
'prf' modes? thmrefs?
;
'full\_prf' modes? thmrefs?
;
modes: '(' (name + ) ')'
;
\end{rail}
\begin{description}
\item @{command "pr"}~@{text "goals, prems"} prints the current
proof state (if present), including the proof context, current facts
and goals. The optional limit arguments affect the number of goals
and premises to be displayed, which is initially 10 for both.
Omitting limit values leaves the current setting unchanged.
\item @{command "thm"}~@{text "a\<^sub>1 \<dots> a\<^sub>n"} retrieves
theorems from the current theory or proof context. Note that any
attributes included in the theorem specifications are applied to a
temporary context derived from the current theory or proof; the
result is discarded, i.e.\ attributes involved in @{text "a\<^sub>1,
\<dots>, a\<^sub>n"} do not have any permanent effect.
\item @{command "term"}~@{text t} and @{command "prop"}~@{text \<phi>}
read, type-check and print terms or propositions according to the
current theory or proof context; the inferred type of @{text t} is
output as well. Note that these commands are also useful in
inspecting the current environment of term abbreviations.
\item @{command "typ"}~@{text \<tau>} reads and prints types of the
meta-logic according to the current theory or proof context.
\item @{command "prf"} displays the (compact) proof term of the
current proof state (if present), or of the given theorems. Note
that this requires proof terms to be switched on for the current
object logic (see the ``Proof terms'' section of the Isabelle
reference manual for information on how to do this).
\item @{command "full_prf"} is like @{command "prf"}, but displays
the full proof term, i.e.\ also displays information omitted in the
compact proof term, which is denoted by ``@{text _}'' placeholders
there.
\end{description}
All of the diagnostic commands above admit a list of @{text modes}
to be specified, which is appended to the current print mode (see
also \cite{isabelle-ref}). Thus the output behavior may be modified
according particular print mode features. For example, @{command
"pr"}~@{text "(latex xsymbols)"} would print the current proof state
with mathematical symbols and special characters represented in
{\LaTeX} source, according to the Isabelle style
\cite{isabelle-sys}.
Note that antiquotations (cf.\ \secref{sec:antiq}) provide a more
systematic way to include formal items into the printed text
document.
*}
section {* Mixfix annotations *}
text {* Mixfix annotations specify concrete \emph{inner syntax} of
Isabelle types and terms. Some commands such as @{command "types"}
(see \secref{sec:types-pure}) admit infixes only, while @{command
"consts"} (see \secref{sec:consts}) and @{command "syntax"} (see
\secref{sec:syn-trans}) support the full range of general mixfixes
and binders.
\indexouternonterm{infix}\indexouternonterm{mixfix}\indexouternonterm{structmixfix}
\begin{rail}
infix: '(' ('infix' | 'infixl' | 'infixr') string nat ')'
;
mixfix: infix | '(' string prios? nat? ')' | '(' 'binder' string prios? nat ')'
;
structmixfix: mixfix | '(' 'structure' ')'
;
prios: '[' (nat + ',') ']'
;
\end{rail}
Here the \railtok{string} specifications refer to the actual mixfix
template, which may include literal text, spacing, blocks, and
arguments (denoted by ``@{text _}''); the special symbol
``@{verbatim "\<index>"}'' (printed as ``@{text "\<index>"}'') represents an index
argument that specifies an implicit structure reference (see also
\secref{sec:locale}). Infix and binder declarations provide common
abbreviations for particular mixfix declarations. So in practice,
mixfix templates mostly degenerate to literal text for concrete
syntax, such as ``@{verbatim "++"}'' for an infix symbol.
\medskip In full generality, mixfix declarations work as follows.
Suppose a constant @{text "c :: \<tau>\<^sub>1 \<Rightarrow> \<dots> \<tau>\<^sub>n \<Rightarrow> \<tau>"} is
annotated by @{text "(mixfix [p\<^sub>1, \<dots>, p\<^sub>n] p)"}, where @{text
"mixfix"} is a string @{text "d\<^sub>0 _ d\<^sub>1 _ \<dots> _ d\<^sub>n"} consisting of
delimiters that surround argument positions as indicated by
underscores.
Altogether this determines a production for a context-free priority
grammar, where for each argument @{text "i"} the syntactic category
is determined by @{text "\<tau>\<^sub>i"} (with priority @{text "p\<^sub>i"}), and
the result category is determined from @{text "\<tau>"} (with
priority @{text "p"}). Priority specifications are optional, with
default 0 for arguments and 1000 for the result.
Since @{text "\<tau>"} may be again a function type, the constant
type scheme may have more argument positions than the mixfix
pattern. Printing a nested application @{text "c t\<^sub>1 \<dots> t\<^sub>m"} for
@{text "m > n"} works by attaching concrete notation only to the
innermost part, essentially by printing @{text "(c t\<^sub>1 \<dots> t\<^sub>n) \<dots> t\<^sub>m"}
instead. If a term has fewer arguments than specified in the mixfix
template, the concrete syntax is ignored.
\medskip A mixfix template may also contain additional directives
for pretty printing, notably spaces, blocks, and breaks. The
general template format is a sequence over any of the following
entities.
\begin{itemize}
\item @{text "\<^bold>d"} is a delimiter, namely a non-empty
sequence of characters other than the special characters @{text "'"}
(single quote), @{text "_"} (underscore), @{text "\<index>"} (index
symbol), @{text "/"} (slash), @{text "("} and @{text ")"}
(parentheses).
A single quote escapes the special meaning of these meta-characters,
producing a literal version of the following character, unless that
is a blank. A single quote followed by a blank separates
delimiters, without affecting printing, but input tokens may have
additional white space here.
\item @{text "_"} is an argument position, which stands for a
certain syntactic category in the underlying grammar.
\item @{text "\<index>"} is an indexed argument position; this is
the place where implicit structure arguments can be attached.
\item @{text "\<^bold>s"} is a non-empty sequence of spaces for
printing. This and the following specifications do not affect
parsing at all.
\item @{text "(\<^bold>n"} opens a pretty printing block. The
optional number specifies how much indentation to add when a line
break occurs within the block. If the parenthesis is not followed
by digits, the indentation defaults to 0. A block specified via
@{text "(00"} is unbreakable.
\item @{text ")"} closes a pretty printing block.
\item @{text "//"} forces a line break.
\item @{text "/\<^bold>s"} allows a line break. Here @{text
"\<^bold>s"} stands for the string of spaces (zero or more) right
after the slash. These spaces are printed if the break is
\emph{not} taken.
\end{itemize}
For example, the template @{text "(_ +/ _)"} specifies an infix
operator. There are two argument positions; the delimiter @{text
"+"} is preceded by a space and followed by a space or line break;
the entire phrase is a pretty printing block.
The general idea of pretty printing with blocks and breaks is also
described in \cite{paulson-ml2}.
*}
section {* Additional term notation *}
text {*
\begin{matharray}{rcll}
@{command_def "notation"} & : & @{text "local_theory \<rightarrow> local_theory"} \\
@{command_def "no_notation"} & : & @{text "local_theory \<rightarrow> local_theory"} \\
\end{matharray}
\begin{rail}
('notation' | 'no\_notation') target? mode? (nameref structmixfix + 'and')
;
\end{rail}
\begin{description}
\item @{command "notation"}~@{text "c (mx)"} associates mixfix
syntax with an existing constant or fixed variable. This is a
robust interface to the underlying @{command "syntax"} primitive
(\secref{sec:syn-trans}). Type declaration and internal syntactic
representation of the given entity is retrieved from the context.
\item @{command "no_notation"} is similar to @{command "notation"},
but removes the specified syntax annotation from the present
context.
\end{description}
*}
section {* Syntax and translations \label{sec:syn-trans} *}
text {*
\begin{matharray}{rcl}
@{command_def "nonterminals"} & : & @{text "theory \<rightarrow> theory"} \\
@{command_def "syntax"} & : & @{text "theory \<rightarrow> theory"} \\
@{command_def "no_syntax"} & : & @{text "theory \<rightarrow> theory"} \\
@{command_def "translations"} & : & @{text "theory \<rightarrow> theory"} \\
@{command_def "no_translations"} & : & @{text "theory \<rightarrow> theory"} \\
\end{matharray}
\begin{rail}
'nonterminals' (name +)
;
('syntax' | 'no\_syntax') mode? (constdecl +)
;
('translations' | 'no\_translations') (transpat ('==' | '=>' | '<=' | rightleftharpoons | rightharpoonup | leftharpoondown) transpat +)
;
mode: ('(' ( name | 'output' | name 'output' ) ')')
;
transpat: ('(' nameref ')')? string
;
\end{rail}
\begin{description}
\item @{command "nonterminals"}~@{text c} declares a type
constructor @{text c} (without arguments) to act as purely syntactic
type: a nonterminal symbol of the inner syntax.
\item @{command "syntax"}~@{text "(mode) decls"} is similar to
@{command "consts"}~@{text decls}, except that the actual logical
signature extension is omitted. Thus the context free grammar of
Isabelle's inner syntax may be augmented in arbitrary ways,
independently of the logic. The @{text mode} argument refers to the
print mode that the grammar rules belong; unless the @{keyword_ref
"output"} indicator is given, all productions are added both to the
input and output grammar.
\item @{command "no_syntax"}~@{text "(mode) decls"} removes grammar
declarations (and translations) resulting from @{text decls}, which
are interpreted in the same manner as for @{command "syntax"} above.
\item @{command "translations"}~@{text rules} specifies syntactic
translation rules (i.e.\ macros): parse~/ print rules (@{text "\<rightleftharpoons>"}),
parse rules (@{text "\<rightharpoonup>"}), or print rules (@{text "\<leftharpoondown>"}).
Translation patterns may be prefixed by the syntactic category to be
used for parsing; the default is @{text logic}.
\item @{command "no_translations"}~@{text rules} removes syntactic
translation rules, which are interpreted in the same manner as for
@{command "translations"} above.
\end{description}
*}
section {* Syntax translation functions *}
text {*
\begin{matharray}{rcl}
@{command_def "parse_ast_translation"} & : & @{text "theory \<rightarrow> theory"} \\
@{command_def "parse_translation"} & : & @{text "theory \<rightarrow> theory"} \\
@{command_def "print_translation"} & : & @{text "theory \<rightarrow> theory"} \\
@{command_def "typed_print_translation"} & : & @{text "theory \<rightarrow> theory"} \\
@{command_def "print_ast_translation"} & : & @{text "theory \<rightarrow> theory"} \\
\end{matharray}
\begin{rail}
( 'parse\_ast\_translation' | 'parse\_translation' | 'print\_translation' |
'typed\_print\_translation' | 'print\_ast\_translation' ) ('(advanced)')? text
;
\end{rail}
Syntax translation functions written in ML admit almost arbitrary
manipulations of Isabelle's inner syntax. Any of the above commands
have a single \railqtok{text} argument that refers to an ML
expression of appropriate type, which are as follows by default:
%FIXME proper antiquotations
\begin{ttbox}
val parse_ast_translation : (string * (ast list -> ast)) list
val parse_translation : (string * (term list -> term)) list
val print_translation : (string * (term list -> term)) list
val typed_print_translation :
(string * (bool -> typ -> term list -> term)) list
val print_ast_translation : (string * (ast list -> ast)) list
\end{ttbox}
If the @{text "(advanced)"} option is given, the corresponding
translation functions may depend on the current theory or proof
context. This allows to implement advanced syntax mechanisms, as
translations functions may refer to specific theory declarations or
auxiliary proof data.
See also \cite[\S8]{isabelle-ref} for more information on the
general concept of syntax transformations in Isabelle.
%FIXME proper antiquotations
\begin{ttbox}
val parse_ast_translation:
(string * (Proof.context -> ast list -> ast)) list
val parse_translation:
(string * (Proof.context -> term list -> term)) list
val print_translation:
(string * (Proof.context -> term list -> term)) list
val typed_print_translation:
(string * (Proof.context -> bool -> typ -> term list -> term)) list
val print_ast_translation:
(string * (Proof.context -> ast list -> ast)) list
\end{ttbox}
*}
end