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Diffstat (limited to 'doc/sphinx/language/gallina-extensions.rst')
| -rw-r--r-- | doc/sphinx/language/gallina-extensions.rst | 24 |
1 files changed, 13 insertions, 11 deletions
diff --git a/doc/sphinx/language/gallina-extensions.rst b/doc/sphinx/language/gallina-extensions.rst index c21d8d4ec..509ac92f8 100644 --- a/doc/sphinx/language/gallina-extensions.rst +++ b/doc/sphinx/language/gallina-extensions.rst @@ -23,8 +23,9 @@ expressions. In this sense, the :cmd:`Record` construction allows defining .. _record_grammar: .. productionlist:: `sentence` - record : `record_keyword` `ident` [ `binders` ] [: `sort` ] := [ `ident` ] { [ `field` ; … ; `field` ] }. + record : `record_keyword` `record_body` with … with `record_body` record_keyword : Record | Inductive | CoInductive + record_body : `ident` [ `binders` ] [: `sort` ] := [ `ident` ] { [ `field` ; … ; `field` ] }. field : `ident` [ `binders` ] : `type` [ where `notation` ] : | `ident` [ `binders` ] [: `type` ] := `term` @@ -167,12 +168,13 @@ and the syntax `term.(@qualid` |term_1| |term_n| `)` to `@qualid` |term_1| `…` In each case, `term` is the object projected and the other arguments are the parameters of the inductive type. + .. note:: Records defined with the ``Record`` keyword are not allowed to be recursive (references to the record's name in the type of its field raises an error). To define recursive records, one can use the ``Inductive`` and ``CoInductive`` keywords, resulting in an inductive or co-inductive record. - A *caveat*, however, is that records cannot appear in mutually inductive - (or co-inductive) definitions. + Definition of mutal inductive or co-inductive records are also allowed, as long + as all of the types in the block are records. .. note:: Induction schemes are automatically generated for inductive records. Automatic generation of induction schemes for non-recursive records @@ -1347,7 +1349,7 @@ folder ``path/fOO/Bar`` maps to ``Lib.fOO.Bar``. Subdirectories corresponding to invalid |Coq| identifiers are skipped, and, by convention, subdirectories named ``CVS`` or ``_darcs`` are skipped too. -Thanks to this mechanism, .vo files are made available through the +Thanks to this mechanism, ``.vo`` files are made available through the logical name of the folder they are in, extended with their own basename. For example, the name associated to the file ``path/fOO/Bar/File.vo`` is ``Lib.fOO.Bar.File``. The same caveat applies for @@ -1358,17 +1360,17 @@ wrong loadpath afterwards. Some folders have a special status and are automatically put in the path. |Coq| commands associate automatically a logical path to files in the repository trees rooted at the directory from where the command is -launched, coqlib/user-contrib/, the directories listed in the -`$COQPATH`, `${XDG_DATA_HOME}/coq/` and `${XDG_DATA_DIRS}/coq/` -environment variables (see`http://standards.freedesktop.org/basedir- -spec/basedir-spec-latest.html`_) with the same physical-to-logical -translation and with an empty logical prefix. +launched, ``coqlib/user-contrib/``, the directories listed in the +``$COQPATH``, ``${XDG_DATA_HOME}/coq/`` and ``${XDG_DATA_DIRS}/coq/`` +environment variables (see `XDG base directory specification +<http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html>`_) +with the same physical-to-logical translation and with an empty logical prefix. The command line option ``-R`` is a variant of ``-Q`` which has the strictly same behavior regarding loadpaths, but which also makes the corresponding ``.vo`` files available through their short names in a way not unlike the ``Import`` command (see :ref:`here <import_qualid>`). For instance, ``-R`` `path` ``Lib`` -associates to the ``filepath/fOO/Bar/File.vo`` the logical name +associates to the file path `path`\ ``/path/fOO/Bar/File.vo`` the logical name ``Lib.fOO.Bar.File``, but allows this file to be accessed through the short names ``fOO.Bar.File,Bar.File`` and ``File``. If several files with identical base name are present in different subdirectories of a @@ -2226,7 +2228,7 @@ existential variable used in the same context as its context of definition is wr Check (fun x y => _) 0 1. Existential variables can be named by the user upon creation using -the syntax ``?``\ `ident`. This is useful when the existential +the syntax :n:`?[@ident]`. This is useful when the existential variable needs to be explicitly handled later in the script (e.g. with a named-goal selector, see :ref:`goal-selectors`). |