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Boost-Commit : |
Subject: [Boost-commit] svn:boost r79465 - in trunk: boost/proto/transform/detail libs/proto/doc libs/proto/doc/reference libs/proto/doc/reference/transform
From: eric_at_[hidden]
Date: 2012-07-13 00:59:55
Author: eric_niebler
Date: 2012-07-13 00:59:53 EDT (Fri, 13 Jul 2012)
New Revision: 79465
URL: http://svn.boost.org/trac/boost/changeset/79465
Log:
reference docs for pseudo-pack expansions in transforms
Text files modified:
trunk/boost/proto/transform/detail/call.hpp | 2
trunk/boost/proto/transform/detail/pack.hpp | 7 ++
trunk/libs/proto/doc/reference.xml | 5 +
trunk/libs/proto/doc/reference/repeat.xml | 36 ++++++------
trunk/libs/proto/doc/reference/transform/call.xml | 28 ++++++++-
trunk/libs/proto/doc/reference/transform/impl.xml | 113 ++++++++++++++++++++++++++++++++++++++++
trunk/libs/proto/doc/reference/transform/lazy.xml | 24 +++++++-
trunk/libs/proto/doc/reference/transform/make.xml | 40 ++++++++-----
trunk/libs/proto/doc/reference/transform/when.xml | 108 ++++++++++++++++++++++++++++++++++++++
9 files changed, 321 insertions(+), 42 deletions(-)
Modified: trunk/boost/proto/transform/detail/call.hpp
==============================================================================
--- trunk/boost/proto/transform/detail/call.hpp (original)
+++ trunk/boost/proto/transform/detail/call.hpp 2012-07-13 00:59:53 EDT (Fri, 13 Jul 2012)
@@ -93,7 +93,7 @@
struct impl
: call<
typename detail::expand_pattern<
- proto::arity_of<Expr>::value
+ proto::arity_of<Expr>::value // BUGBUG this isn't right. Could be pack(_child), should use arity of child!
, BOOST_PP_CAT(A, BOOST_PP_DEC(N))
, detail::BOOST_PP_CAT(expand_pattern_rest_, BOOST_PP_DEC(N))<
Fun
Modified: trunk/boost/proto/transform/detail/pack.hpp
==============================================================================
--- trunk/boost/proto/transform/detail/pack.hpp (original)
+++ trunk/boost/proto/transform/detail/pack.hpp 2012-07-13 00:59:53 EDT (Fri, 13 Jul 2012)
@@ -23,6 +23,7 @@
#include <boost/preprocessor/iteration/iterate.hpp>
#include <boost/mpl/bool.hpp>
#include <boost/mpl/assert.hpp>
+#include <boost/type_traits/is_same.hpp>
#include <boost/proto/proto_fwd.hpp>
#if defined(_MSC_VER) && (_MSC_VER >= 1020)
@@ -52,6 +53,12 @@
template<typename Tfx, typename T>
struct expand_pattern_helper<Tfx, pack(T)>
{
+ // BUGBUG fix me. See comment in transform/detail/call.hpp
+ BOOST_MPL_ASSERT_MSG(
+ (is_same<T, _>::value)
+ , PACK_EXPANSIONS_OF_EXPRESSIONS_OTHER_THAN_THE_CURRENT_NOT_YET_SUPPORTED
+ , (T)
+ );
typedef Tfx type(T);
typedef mpl::true_ applied;
};
Modified: trunk/libs/proto/doc/reference.xml
==============================================================================
--- trunk/libs/proto/doc/reference.xml (original)
+++ trunk/libs/proto/doc/reference.xml 2012-07-13 00:59:53 EDT (Fri, 13 Jul 2012)
@@ -609,6 +609,11 @@
</listitem>
<listitem>
<computeroutput>
+ <classname alt="boost::proto::pack">proto::pack</classname>
+ </computeroutput>
+ </listitem>
+ <listitem>
+ <computeroutput>
<classname alt="boost::proto::pass_through">proto::pass_through</classname>
</computeroutput>
</listitem>
Modified: trunk/libs/proto/doc/reference/repeat.xml
==============================================================================
--- trunk/libs/proto/doc/reference/repeat.xml (original)
+++ trunk/libs/proto/doc/reference/repeat.xml 2012-07-13 00:59:53 EDT (Fri, 13 Jul 2012)
@@ -305,7 +305,7 @@
Generates sequences like
<computeroutput>
typename A<subscript>0</subscript>,
- typename A<subscript>1</subscript>, ...
+ typename A<subscript>1</subscript>, …
typename A<subscript>N-1</subscript>
</computeroutput>.
</purpose>
@@ -318,7 +318,7 @@
<computeroutput>BOOST_PROTO_typename_A(<replaceable>N</replaceable>)</computeroutput> generates sequences like:
</para>
<para>
- <programlisting>typename A<subscript>0</subscript>, typename A<subscript>1</subscript>, ... typename A<subscript>N-1</subscript></programlisting>
+ <programlisting>typename A<subscript>0</subscript>, typename A<subscript>1</subscript>, … typename A<subscript>N-1</subscript></programlisting>
</para>
</description>
</macro>
@@ -329,7 +329,7 @@
Generates sequences like
<computeroutput>
A<subscript>0</subscript> const &,
- A<subscript>1</subscript> const &, ...
+ A<subscript>1</subscript> const &, …
A<subscript>N-1</subscript> const &
</computeroutput>.
</purpose>
@@ -342,7 +342,7 @@
<computeroutput>BOOST_PROTO_A_const_ref(<replaceable>N</replaceable>)</computeroutput> generates sequences like:
</para>
<para>
- <programlisting>A<subscript>0</subscript> const &, A<subscript>1</subscript> const &, ... A<subscript>N-1</subscript> const &</programlisting>
+ <programlisting>A<subscript>0</subscript> const &, A<subscript>1</subscript> const &, … A<subscript>N-1</subscript> const &</programlisting>
</para>
</description>
</macro>
@@ -353,7 +353,7 @@
Generates sequences like
<computeroutput>
A<subscript>0</subscript> &,
- A<subscript>1</subscript> &, ...
+ A<subscript>1</subscript> &, …
A<subscript>N-1</subscript> &
</computeroutput>.
</purpose>
@@ -366,7 +366,7 @@
<computeroutput>BOOST_PROTO_A_ref(<replaceable>N</replaceable>)</computeroutput> generates sequences like:
</para>
<para>
- <programlisting>A<subscript>0</subscript> &, A<subscript>1</subscript> &, ... A<subscript>N-1</subscript> &</programlisting>
+ <programlisting>A<subscript>0</subscript> &, A<subscript>1</subscript> &, … A<subscript>N-1</subscript> &</programlisting>
</para>
</description>
</macro>
@@ -377,7 +377,7 @@
Generates sequences like
<computeroutput>
A<subscript>0</subscript>,
- A<subscript>1</subscript>, ...
+ A<subscript>1</subscript>, …
A<subscript>N-1</subscript>
</computeroutput>.
</purpose>
@@ -390,7 +390,7 @@
<computeroutput>BOOST_PROTO_A(<replaceable>N</replaceable>)</computeroutput> generates sequences like:
</para>
<para>
- <programlisting>A<subscript>0</subscript>, A<subscript>1</subscript>, ... A<subscript>N-1</subscript></programlisting>
+ <programlisting>A<subscript>0</subscript>, A<subscript>1</subscript>, … A<subscript>N-1</subscript></programlisting>
</para>
</description>
</macro>
@@ -401,7 +401,7 @@
Generates sequences like
<computeroutput>
A<subscript>0</subscript> const,
- A<subscript>1</subscript> const, ...
+ A<subscript>1</subscript> const, …
A<subscript>N-1</subscript> const
</computeroutput>.
</purpose>
@@ -414,7 +414,7 @@
<computeroutput>BOOST_PROTO_A_const(<replaceable>N</replaceable>)</computeroutput> generates sequences like:
</para>
<para>
- <programlisting>A<subscript>0</subscript> const, A<subscript>1</subscript> const, ... A<subscript>N-1</subscript> const</programlisting>
+ <programlisting>A<subscript>0</subscript> const, A<subscript>1</subscript> const, … A<subscript>N-1</subscript> const</programlisting>
</para>
</description>
</macro>
@@ -425,7 +425,7 @@
Generates sequences like
<computeroutput>
A<subscript>0</subscript> const & a<subscript>0</subscript>,
- A<subscript>1</subscript> const & a<subscript>1</subscript>, ...
+ A<subscript>1</subscript> const & a<subscript>1</subscript>, …
A<subscript>N-1</subscript> const & a<subscript>N-1</subscript>
</computeroutput>.
</purpose>
@@ -438,7 +438,7 @@
<computeroutput>BOOST_PROTO_A_const_ref_a(<replaceable>N</replaceable>)</computeroutput> generates sequences like:
</para>
<para>
- <programlisting>A<subscript>0</subscript> const & a<subscript>0</subscript>, A<subscript>1</subscript> const & a<subscript>1</subscript>, ... A<subscript>N-1</subscript> const & a<subscript>N-1</subscript></programlisting>
+ <programlisting>A<subscript>0</subscript> const & a<subscript>0</subscript>, A<subscript>1</subscript> const & a<subscript>1</subscript>, … A<subscript>N-1</subscript> const & a<subscript>N-1</subscript></programlisting>
</para>
</description>
</macro>
@@ -449,7 +449,7 @@
Generates sequences like
<computeroutput>
A<subscript>0</subscript> & a<subscript>0</subscript>,
- A<subscript>1</subscript> & a<subscript>1</subscript>, ...
+ A<subscript>1</subscript> & a<subscript>1</subscript>, …
A<subscript>N-1</subscript> & a<subscript>N-1</subscript>
</computeroutput>.
</purpose>
@@ -462,7 +462,7 @@
<computeroutput>BOOST_PROTO_A_ref_a(<replaceable>N</replaceable>)</computeroutput> generates sequences like:
</para>
<para>
- <programlisting>A<subscript>0</subscript> & a<subscript>0</subscript>, A<subscript>1</subscript> & a<subscript>1</subscript>, ... A<subscript>N-1</subscript> & a<subscript>N-1</subscript></programlisting>
+ <programlisting>A<subscript>0</subscript> & a<subscript>0</subscript>, A<subscript>1</subscript> & a<subscript>1</subscript>, … A<subscript>N-1</subscript> & a<subscript>N-1</subscript></programlisting>
</para>
</description>
</macro>
@@ -473,7 +473,7 @@
Generates sequences like
<computeroutput>
boost::ref(a<subscript>0</subscript>),
- boost::ref(a<subscript>1</subscript>), ...
+ boost::ref(a<subscript>1</subscript>), …
boost::ref(a<subscript>N-1</subscript>)
</computeroutput>.
</purpose>
@@ -486,7 +486,7 @@
<computeroutput>BOOST_PROTO_ref_a(<replaceable>N</replaceable>)</computeroutput> generates sequences like:
</para>
<para>
- <programlisting>boost::ref(a<subscript>0</subscript>), boost::ref(a<subscript>1</subscript>), ... boost::ref(a<subscript>N-1</subscript>)</programlisting>
+ <programlisting>boost::ref(a<subscript>0</subscript>), boost::ref(a<subscript>1</subscript>), … boost::ref(a<subscript>N-1</subscript>)</programlisting>
</para>
</description>
</macro>
@@ -497,7 +497,7 @@
Generates sequences like
<computeroutput>
a<subscript>0</subscript>,
- a<subscript>1</subscript>, ...
+ a<subscript>1</subscript>, …
a<subscript>N-1</subscript>
</computeroutput>.
</purpose>
@@ -510,7 +510,7 @@
<computeroutput>BOOST_PROTO_a(<replaceable>N</replaceable>)</computeroutput> generates sequences like:
</para>
<para>
- <programlisting>a<subscript>0</subscript>, a<subscript>1</subscript>, ... a<subscript>N-1</subscript></programlisting>
+ <programlisting>a<subscript>0</subscript>, a<subscript>1</subscript>, … a<subscript>N-1</subscript></programlisting>
</para>
</description>
</macro>
Modified: trunk/libs/proto/doc/reference/transform/call.xml
==============================================================================
--- trunk/libs/proto/doc/reference/transform/call.xml (original)
+++ trunk/libs/proto/doc/reference/transform/call.xml 2012-07-13 00:59:53 EDT (Fri, 13 Jul 2012)
@@ -105,15 +105,26 @@
<listitem>
<para>
If <computeroutput>T</computeroutput> is of the form
- <computeroutput><conceptname>PolymorphicFunctionObject</conceptname>(A<subscript>0</subscript>,...A<subscript>n</subscript>)</computeroutput>, then
+ <computeroutput><conceptname>PolymorphicFunctionObject</conceptname>(A<subscript>0</subscript>,…A<subscript>n</subscript>)</computeroutput>, then
<computeroutput>result_type</computeroutput> is:
<programlisting>typename boost::result_of<PolymorphicFunctionObject(
typename boost::result_of<<classname>when</classname><<classname>_</classname>,A<subscript>0</subscript>>(Expr, State, Data)>::type,
- ...
+ …
typename boost::result_of<<classname>when</classname><<classname>_</classname>,A<subscript>n</subscript>>(Expr, State, Data)>::type
>::type</programlisting>
</para>
</listitem>
+ <listitem>
+ <para>
+ If <computeroutput>T</computeroutput> is of the form
+ <computeroutput><conceptname>PolymorphicFunctionObject</conceptname>(A<subscript>0</subscript>,…A<subscript>n</subscript> ...)</computeroutput>, then
+ let <computeroutput>T'</computeroutput> be <computeroutput><conceptname>PolymorphicFunctionObject</conceptname>(A<subscript>0</subscript>,…A<subscript>n-1</subscript>, <replaceable>S</replaceable>)</computeroutput>,
+ where <replaceable>S</replaceable> is a type sequence computed from the unpacking expression <computeroutput>A<subscript>n</subscript></computeroutput>
+ as described in the reference for <computeroutput><classname>proto::pack</classname></computeroutput>.
+ Then, <computeroutput>result_type</computeroutput> is:
+ <programlisting><computeroutput>typename <classname>proto::call</classname><T'>::impl<Expr,State,Data>::result_type</computeroutput></programlisting>
+ </para>
+ </listitem>
</itemizedlist>
</para>
</description>
@@ -188,7 +199,7 @@
<listitem>
<para>
If <computeroutput>T</computeroutput> is of the form
- <computeroutput><conceptname>PolymorphicFunctionObject</conceptname>(A<subscript>0</subscript>,...A<subscript>n</subscript>)</computeroutput>, then
+ <computeroutput><conceptname>PolymorphicFunctionObject</conceptname>(A<subscript>0</subscript>,…A<subscript>n</subscript>)</computeroutput>, then
return:
<programlisting>PolymorphicFunctionObject()(
<classname>when</classname><<classname>_</classname>,A<subscript>0</subscript>>()(expr, state, data),
@@ -197,6 +208,17 @@
)</programlisting>
</para>
</listitem>
+ <listitem>
+ <para>
+ If <computeroutput>T</computeroutput> is of the form
+ <computeroutput><conceptname>PolymorphicFunctionObject</conceptname>(A<subscript>0</subscript>,…A<subscript>n</subscript> ...)</computeroutput>, then
+ let <computeroutput>T'</computeroutput> be <computeroutput><conceptname>PolymorphicFunctionObject</conceptname>(A<subscript>0</subscript>,…A<subscript>n-1</subscript>, <replaceable>S</replaceable>)</computeroutput>,
+ where <replaceable>S</replaceable> is a type sequence computed from the unpacking expression <computeroutput>A<subscript>n</subscript></computeroutput>
+ as described in the reference for <computeroutput><classname>proto::pack</classname></computeroutput>.
+ Then, return:
+ <programlisting><computeroutput><classname>proto::call</classname><T'>()(expr, state, data)</computeroutput></programlisting>
+ </para>
+ </listitem>
</itemizedlist>
</para>
</description>
Modified: trunk/libs/proto/doc/reference/transform/impl.xml
==============================================================================
--- trunk/libs/proto/doc/reference/transform/impl.xml (original)
+++ trunk/libs/proto/doc/reference/transform/impl.xml 2012-07-13 00:59:53 EDT (Fri, 13 Jul 2012)
@@ -183,6 +183,119 @@
<type>typename boost::add_reference<Data const>::type</type>
</typedef>
</struct>
+
+ <!-- proto::pack -->
+ <struct name="pack">
+
+ <purpose>To turn an expression into a pseudo-parameter pack containing the
+ expression's children, for the purpose of expanding the pack expression within
+ a <conceptname>CallableTransform</conceptname> or
+ <conceptname>ObjectTransform</conceptname>.</purpose>
+
+ <description>
+ <para>
+ <computeroutput>proto::pack</computeroutput> is useful within
+ <conceptname>CallableTransform</conceptname>s and
+ <conceptname>ObjectTransform</conceptname>s when one wishes to unpack an expression
+ into a function call or an object constructor. <computeroutput>proto::pack</computeroutput>
+ turns a Proto expression into a pseudo-parameter pack, which may appear in an unpacking
+ pattern to be expanded with the "<computeroutput>...</computeroutput>" syntax.
+ </para>
+
+ <para>
+ <emphasis role="bold">Example:</emphasis>
+ </para>
+
+ <para>
+ <programlisting>// The following demonstrates how to use a pseudo-pack expansion
+// to unpack an expression into a function call.
+
+struct do_sum : <classname alt="boost::proto::callable">proto::callable</classname>
+{
+ typedef int result_type;
+
+ int operator()(int i) const { return i; }
+ int operator()(int i, int j) const { return i + j; }
+ int operator()(int i, int j, int k) const { return i + j + k; }
+};
+
+// Take any n-ary expression where the children are all int terminals and sum all the ints
+struct sum
+ : <classname alt="boost::proto::when">proto::when</classname><
+
+ // Match any nary expression where the children are all int terminals
+ <classname alt="boost::proto::nary_expr">proto::nary_expr</classname><<classname alt="boost::proto::_">_</classname>, <classname alt="boost::proto::vararg">proto::vararg</classname><<classname alt="boost::proto::terminal">proto::terminal</classname><int> > >
+
+ // Turn the current expression into a pseudo-parameter pack, then expand it,
+ // extracting the value from each child in turn.
+ , do_sum(<classname alt="boost::proto::_value">proto::_value</classname>(proto::pack(<classname alt="boost::proto::_">_</classname>))...)
+ >
+{};
+
+int main()
+{
+ <classname alt="boost::proto::terminal">proto::terminal</classname><int>::type i = {42};
+ int result = sum()( i(3,5) ); // Creates a ternary functional-call expression
+ std::cout << "Sum of 42, 3, and 5 : " << result << std::endl;
+}</programlisting>
+ </para>
+
+ <para>
+ The above program displays:
+ </para>
+
+ <para>
+ <computeroutput>Sum of 42, 3, and 5 : 50</computeroutput>
+ </para>
+
+ <para>
+ <emphasis role="bold">Unpacking Patterns:</emphasis>
+ </para>
+
+ <para>
+ Composite transforms (either <conceptname>CallableTransform</conceptname>s or
+ <conceptname>ObjectTransform</conceptname>s) usually have the form
+ <computeroutput>X(A<subscript>0</subscript>,…A<subscript>n</subscript>)</computeroutput>.
+ However, when the argument list in a composite transform is terminated with a C-style
+ vararg ellipsis as in <computeroutput>X(A<subscript>0</subscript>,…A<subscript>n</subscript> ...)</computeroutput>,
+ the final argument <computeroutput>A<subscript>n</subscript></computeroutput> is treated
+ as an <emphasis>unpacking expression</emphasis>.
+ </para>
+
+ <para>
+ An unpacking expression must itself be a composite transform; that is, it must be a
+ function type representing either a <conceptname>CallableTransform</conceptname> or
+ an <conceptname>ObjectTransform</conceptname>. The type <computeroutput>proto::pack(_)</computeroutput>
+ must appear exactly once in the unpacking expression. This type will receive a substitution
+ when the unpacking expression is expanded.
+ </para>
+
+ <para>
+ A composite transform like <computeroutput>X(A<subscript>0</subscript>,…A<subscript>n</subscript> ...)</computeroutput>,
+ when evaluated against a given expression <replaceable>E</replaceable>, state and data, is evaluated as if it were
+ <computeroutput>X(A<subscript>0</subscript>,…A<subscript>n-1</subscript>,<replaceable>S</replaceable>)</computeroutput>
+ where <replaceable>S</replaceable> is a type sequence computed as follows:
+ </para>
+ <para>
+ Let <computeroutput><replaceable>SUB</replaceable>(A,B)</computeroutput> be a type function that replaces every occurence of
+ <computeroutput>proto::pack(_)</computeroutput> within <computeroutput>A</computeroutput> with <computeroutput>B</computeroutput>.
+ <itemizedlist>
+ <listitem>
+ If the expression <replaceable>E</replaceable> is a terminal (i.e. it has arity 0), <replaceable>S</replaceable>
+ is the one-element sequence containing <computeroutput><replaceable>SUB</replaceable>(A<subscript>n</subscript>, <classname alt="boost::proto::_value">proto::_value</classname>)</computeroutput>.
+ </listitem>
+ <listitem>
+ If the expression <replaceable>E</replaceable> is a non-terminal, <replaceable>S</replaceable> is the sequence
+ <computeroutput><replaceable>SUB</replaceable>(A<subscript>n</subscript>, <classname alt="boost::proto::_child_c">proto::_child_c</classname><0>),…
+ <replaceable>SUB</replaceable>(A<subscript>n</subscript>, <classname alt="boost::proto::_child_c">proto::_child_c</classname><<replaceable>M</replaceable>-1>)</computeroutput>, where
+ <replaceable>M</replaceable> is the arity of the expression <replaceable>E</replaceable>.
+ </listitem>
+ </itemizedlist>
+ </para>
+ </description>
+
+ </struct>
+
</namespace>
</namespace>
</header>
Modified: trunk/libs/proto/doc/reference/transform/lazy.xml
==============================================================================
--- trunk/libs/proto/doc/reference/transform/lazy.xml (original)
+++ trunk/libs/proto/doc/reference/transform/lazy.xml 2012-07-13 00:59:53 EDT (Fri, 13 Jul 2012)
@@ -64,9 +64,17 @@
<listitem>
<para>
If <computeroutput>T</computeroutput> if of the form
- <computeroutput>O(A<subscript>0</subscript>,...A<subscript>n</subscript>)</computeroutput>, then let <computeroutput>O'</computeroutput>
+ <computeroutput>O(A<subscript>0</subscript>,…A<subscript>n</subscript>)</computeroutput>, then let <computeroutput>O'</computeroutput>
be <computeroutput>boost::result_of<<classname>proto::make</classname><O>(Expr, State, Data)>::type</computeroutput>
- and let <computeroutput>T'</computeroutput> be <computeroutput>O'(A<subscript>0</subscript>,...A<subscript>n</subscript>)</computeroutput>.
+ and let <computeroutput>T'</computeroutput> be <computeroutput>O'(A<subscript>0</subscript>,…A<subscript>n</subscript>)</computeroutput>.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ If <computeroutput>T</computeroutput> if of the form
+ <computeroutput>O(A<subscript>0</subscript>,…A<subscript>n</subscript> ...)</computeroutput>, then let <computeroutput>O'</computeroutput>
+ be <computeroutput>boost::result_of<<classname>proto::make</classname><O>(Expr, State, Data)>::type</computeroutput>
+ and let <computeroutput>T'</computeroutput> be <computeroutput>O'(A<subscript>0</subscript>,…A<subscript>n</subscript> ...)</computeroutput>.
</para>
</listitem>
<listitem>
@@ -104,9 +112,17 @@
<listitem>
<para>
If <computeroutput>T</computeroutput> if of the form
- <computeroutput>O(A<subscript>0</subscript>,...A<subscript>n</subscript>)</computeroutput>, then let <computeroutput>O'</computeroutput>
+ <computeroutput>O(A<subscript>0</subscript>,…A<subscript>n</subscript>)</computeroutput>, then let <computeroutput>O'</computeroutput>
+ be <computeroutput>boost::result_of<<classname>proto::make</classname><O>(Expr, State, Data)>::type</computeroutput>
+ and let <computeroutput>T'</computeroutput> be <computeroutput>O'(A<subscript>0</subscript>,…A<subscript>n</subscript>)</computeroutput>.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ If <computeroutput>T</computeroutput> if of the form
+ <computeroutput>O(A<subscript>0</subscript>,…A<subscript>n</subscript> ...)</computeroutput>, then let <computeroutput>O'</computeroutput>
be <computeroutput>boost::result_of<<classname>proto::make</classname><O>(Expr, State, Data)>::type</computeroutput>
- and let <computeroutput>T'</computeroutput> be <computeroutput>O'(A<subscript>0</subscript>,...A<subscript>n</subscript>)</computeroutput>.
+ and let <computeroutput>T'</computeroutput> be <computeroutput>O'(A<subscript>0</subscript>,…A<subscript>n</subscript> ...)</computeroutput>.
</para>
</listitem>
<listitem>
Modified: trunk/libs/proto/doc/reference/transform/make.xml
==============================================================================
--- trunk/libs/proto/doc/reference/transform/make.xml (original)
+++ trunk/libs/proto/doc/reference/transform/make.xml 2012-07-13 00:59:53 EDT (Fri, 13 Jul 2012)
@@ -149,9 +149,7 @@
<para>
The purpose of <computeroutput>proto::make<></computeroutput> is to annotate a transform as
an <conceptname>ObjectTransform</conceptname> so that
- <computeroutput>
- <classname alt="proto::when">proto::when<></classname>
- </computeroutput> knows
+ <computeroutput><classname alt="proto::when">proto::when<></classname></computeroutput> knows
how to apply it.
</para>
@@ -180,7 +178,8 @@
</para>
<para>
If <computeroutput>T</computeroutput> is an <conceptname>ObjectTransform</conceptname> of the form
- <computeroutput>Object(A<subscript>0</subscript>,...A<subscript>n</subscript>)</computeroutput>,
+ <computeroutput>Object(A<subscript>0</subscript>,…A<subscript>n</subscript>)</computeroutput> or
+ <computeroutput>Object(A<subscript>0</subscript>,…A<subscript>n</subscript> ...)</computeroutput>,
then let <computeroutput>O</computeroutput> be the return type
<computeroutput>Object</computeroutput>. Otherwise, let <computeroutput>O</computeroutput>
be <computeroutput>T</computeroutput>. The <computeroutput>result_type</computeroutput> typedef is
@@ -200,7 +199,7 @@
</listitem>
<listitem>
If <computeroutput>O</computeroutput> is a template like
- <computeroutput><classname>proto::noinvoke</classname><S<X<subscript>0</subscript>,...X<subscript>n</subscript>> ></computeroutput>,
+ <computeroutput><classname>proto::noinvoke</classname><S<X<subscript>0</subscript>,…X<subscript>n</subscript>> ></computeroutput>,
then the result type is calculated as follows:
<itemizedlist>
<listitem>
@@ -222,7 +221,7 @@
<para>
The result type is
<computeroutput>
- S<X<subscript>0</subscript>',...X<subscript>n</subscript>'>
+ S<X<subscript>0</subscript>',…X<subscript>n</subscript>'>
</computeroutput>.
</para>
</listitem>
@@ -230,7 +229,7 @@
</listitem>
<listitem>
If <computeroutput>O</computeroutput> is a template like
- <computeroutput>S<X<subscript>0</subscript>,...X<subscript>n</subscript>></computeroutput>,
+ <computeroutput>S<X<subscript>0</subscript>,…X<subscript>n</subscript>></computeroutput>,
then the result type is calculated as follows:
<itemizedlist>
<listitem>
@@ -250,11 +249,11 @@
<para>
If any substitutions took place in the above step and
<computeroutput>
- S<X<subscript>0</subscript>',...X<subscript>n</subscript>'>
+ S<X<subscript>0</subscript>',…X<subscript>n</subscript>'>
</computeroutput> has a nested
<computeroutput>type</computeroutput> typedef, the result type is
<computeroutput>
- S<X<subscript>0</subscript>',...X<subscript>n</subscript>'>::type
+ S<X<subscript>0</subscript>',…X<subscript>n</subscript>'>::type
</computeroutput>.
</para>
</listitem>
@@ -262,7 +261,7 @@
<para>
Otherwise, the result type is
<computeroutput>
- S<X<subscript>0</subscript>',...X<subscript>n</subscript>'>
+ S<X<subscript>0</subscript>',…X<subscript>n</subscript>'>
</computeroutput>.
</para>
</listitem>
@@ -306,7 +305,7 @@
<listitem>
<para>
If <computeroutput>T</computeroutput> is of the form
- <computeroutput>O(A<subscript>0</subscript>,...A<subscript>n</subscript>)</computeroutput>, then:
+ <computeroutput>O(A<subscript>0</subscript>,…A<subscript>n</subscript>)</computeroutput>, then:
</para>
<itemizedlist>
<listitem>
@@ -317,7 +316,7 @@
and return an object <computeroutput>that</computeroutput> as follows:
<programlisting>result_type that = {
<classname>proto::when</classname><<classname>_</classname>, A<subscript>0</subscript>>()(expr, state, data),
- ...
+ …
<classname>proto::when</classname><<classname>_</classname>, A<subscript>n</subscript>>()(expr, state, data)
};</programlisting>
</para>
@@ -328,7 +327,7 @@
and return an object <computeroutput>that</computeroutput> as follows:
<programlisting>result_type that(
<classname>proto::when</classname><<classname>_</classname>, A<subscript>0</subscript>>()(expr, state, data),
- ...
+ …
<classname>proto::when</classname><<classname>_</classname>, A<subscript>n</subscript>>()(expr, state, data)
);</programlisting>
</para>
@@ -337,9 +336,18 @@
</listitem>
<listitem>
<para>
- Otherwise, construct
- and return an object <computeroutput>that</computeroutput> as follows:
- <programlisting>result_type that = result_type();</programlisting>
+ If <computeroutput>T</computeroutput> is of the form
+ <computeroutput>O(A<subscript>0</subscript>,…A<subscript>n</subscript> ...)</computeroutput>,
+ then let <computeroutput>T'</computeroutput> be <computeroutput>O(A<subscript>0</subscript>,…A<subscript>n-1</subscript>, <replaceable>S</replaceable>)</computeroutput>,
+ where <replaceable>S</replaceable> is a type sequence computed from the unpacking expression <computeroutput>A<subscript>n</subscript></computeroutput>
+ as described in the reference for <computeroutput><classname>proto::pack</classname></computeroutput>. Then, return:
+ <programlisting>proto::make<T'>()(expr, state, data)</programlisting>
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Otherwise, construct and return an object <computeroutput>that</computeroutput>
+ as follows: <programlisting>result_type that = result_type();</programlisting>
</para>
</listitem>
</itemizedlist>
Modified: trunk/libs/proto/doc/reference/transform/when.xml
==============================================================================
--- trunk/libs/proto/doc/reference/transform/when.xml (original)
+++ trunk/libs/proto/doc/reference/transform/when.xml 2012-07-13 00:59:53 EDT (Fri, 13 Jul 2012)
@@ -199,6 +199,114 @@
<struct-specialization name="when">
<template>
<template-type-parameter name="Grammar"/>
+ <template-type-parameter name="R"/>
+ <template-type-parameter name="A" pack="1"/>
+ </template>
+ <specialization>
+ <template-arg>Grammar</template-arg>
+ <template-arg>R(A..., ...)</template-arg>
+ </specialization>
+ <inherit><type><classname>proto::transform</classname>< when<Grammar, R(A..., ...)> ></type></inherit>
+ <purpose>A grammar element and a <conceptname>Transform</conceptname> that associates a
+ transform with the grammar. </purpose>
+ <description>
+ <para>
+ Use <computeroutput>proto::when<></computeroutput> to override a grammar's default
+ transform with a custom transform. It is for use when composing larger transforms by associating
+ smaller transforms with individual rules in your grammar.
+ </para>
+ <para>
+ The <computeroutput>when<G, R(A..., ...)></computeroutput> form accepts either a
+ <conceptname>CallableTransform</conceptname> or an <conceptname>ObjectTransform</conceptname> as its
+ second parameter. <computeroutput>proto::when<></computeroutput> uses
+ <computeroutput><classname>proto::is_callable</classname><R>::value</computeroutput> to
+ distinguish between the two, and uses
+ <computeroutput><classname>proto::call<></classname></computeroutput> to evaluate
+ <conceptname>CallableTransform</conceptname>s and
+ <computeroutput><classname>proto::make<></classname></computeroutput> to evaluate
+ <conceptname>ObjectTransform</conceptname>s.
+ </para>
+ <para>
+ <emphasis role="bold">Note:</emphasis> In the specialization
+ <computeroutput>when<G, R(A..., ...)></computeroutput>, the first ellipsis denotes a
+ C++11-style variadic template (which is emulated for C++98 compilers). The second ellipsis
+ is a C-style vararg.
+ </para>
+ </description>
+ <struct name="impl">
+ <template>
+ <template-type-parameter name="Expr"/>
+ <template-type-parameter name="State"/>
+ <template-type-parameter name="Data"/>
+ </template>
+ <inherit><type><classname>proto::transform_impl</classname>< Expr, State, Data ></type></inherit>
+ <typedef name="call_">
+ <purpose>For exposition only</purpose>
+ <type><classname>proto::call</classname><R(A..., ...)></type>
+ </typedef>
+ <typedef name="make_">
+ <purpose>For exposition only</purpose>
+ <type><classname>proto::make</classname><R(A..., ...)></type>
+ </typedef>
+ <typedef name="which">
+ <purpose>For exposition only</purpose>
+ <type>typename mpl::if_<<classname>proto::is_callable</classname><R>,call_,make_>::type</type>
+ </typedef>
+ <typedef name="result_type">
+ <type>typename boost::result_of<which(Expr, State, Data)>::type</type>
+ </typedef>
+ <method-group name="public member functions">
+ <method name="operator()" cv="const">
+ <type>result_type</type>
+ <parameter name="expr">
+ <paramtype>typename impl::expr_param</paramtype>
+ <description>
+ <para>The current expression </para>
+ </description>
+ </parameter>
+ <parameter name="state">
+ <paramtype>typename impl::state_param</paramtype>
+ <description>
+ <para>The current state </para>
+ </description>
+ </parameter>
+ <parameter name="data">
+ <paramtype>typename impl::data_param</paramtype>
+ <description>
+ <para>An arbitrary data </para>
+ </description>
+ </parameter>
+ <description>
+ <para>
+ Evaluate <computeroutput>R(A..., ...)</computeroutput> as a transform either with
+ <computeroutput><classname>proto::call<></classname></computeroutput> or with
+ <computeroutput><classname>proto::make<></classname></computeroutput> depending
+ on whether <computeroutput><classname>proto::is_callable</classname><R>::value</computeroutput>
+ is <computeroutput>true</computeroutput> or <computeroutput>false</computeroutput>.
+ </para>
+ </description>
+ <requires>
+ <para>
+ <computeroutput><classname>proto::matches</classname><Expr, Grammar>::value</computeroutput>
+ is <computeroutput>true</computeroutput>.
+ </para>
+ </requires>
+ <returns>
+ <para>
+ <computeroutput>which()(expr, state, data)</computeroutput>
+ </para>
+ </returns>
+ </method>
+ </method-group>
+ </struct>
+ <typedef name="proto_grammar">
+ <type>typename Grammar::proto_grammar</type>
+ </typedef>
+ </struct-specialization>
+
+ <struct-specialization name="when">
+ <template>
+ <template-type-parameter name="Grammar"/>
</template>
<specialization>
<template-arg>Grammar</template-arg>
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