/*============================================================================= Phoenix V1.2.1 Copyright (c) 2001-2002 Joel de Guzman Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) ==============================================================================*/ #ifndef PHOENIX_STATEMENTS_HPP #define PHOENIX_STATEMENTS_HPP /////////////////////////////////////////////////////////////////////////////// #include /////////////////////////////////////////////////////////////////////////////// namespace phoenix { /////////////////////////////////////////////////////////////////////////////// // // sequential_composite // // Two or more actors separated by the comma generates a // sequential_composite which is a composite actor. Example: // // actor, // actor, // actor // // The actors are evaluated sequentially. The result type of this // is void. Note that the last actor should not have a trailing // comma. // /////////////////////////////////////////////////////////////////////////////// template struct sequential_composite { typedef sequential_composite self_t; template struct result { typedef void type; }; sequential_composite(A0 const& _0, A1 const& _1) : a0(_0), a1(_1) {} template void eval(TupleT const& args) const { a0.eval(args); a1.eval(args); } A0 a0; A1 a1; // actors }; ////////////////////////////////// template inline actor, actor > > operator,(actor const& _0, actor const& _1) { return sequential_composite, actor >(_0, _1); } /////////////////////////////////////////////////////////////////////////////// // // if_then_else_composite // // This composite has two (2) forms: // // if_(condition) // [ // statement // ] // // and // // if_(condition) // [ // true_statement // ] // .else_ // [ // false_statement // ] // // where condition is an actor that evaluates to bool. If condition // is true, the true_statement (again an actor) is executed // otherwise, the false_statement (another actor) is executed. The // result type of this is void. Note the trailing underscore after // if_ and the leading dot and the trailing underscore before // and after .else_. // /////////////////////////////////////////////////////////////////////////////// template struct if_then_else_composite { typedef if_then_else_composite self_t; template struct result { typedef void type; }; if_then_else_composite( CondT const& cond_, ThenT const& then_, ElseT const& else__) : cond(cond_), then(then_), else_(else__) {} template void eval(TupleT const& args) const { if (cond.eval(args)) then.eval(args); else else_.eval(args); } CondT cond; ThenT then; ElseT else_; // actors }; ////////////////////////////////// template struct else_gen { else_gen(CondT const& cond_, ThenT const& then_) : cond(cond_), then(then_) {} template actor::type> > operator[](ElseT const& else_) { typedef if_then_else_composite::type> result; return result(cond, then, as_actor::convert(else_)); } CondT cond; ThenT then; }; ////////////////////////////////// template struct if_then_composite { typedef if_then_composite self_t; template struct result { typedef void type; }; if_then_composite(CondT const& cond_, ThenT const& then_) : cond(cond_), then(then_), else_(cond, then) {} template void eval(TupleT const& args) const { if (cond.eval(args)) then.eval(args); } CondT cond; ThenT then; // actors else_gen else_; }; ////////////////////////////////// template struct if_gen { if_gen(CondT const& cond_) : cond(cond_) {} template actor::type, typename as_actor::type> > operator[](ThenT const& then) const { typedef if_then_composite< typename as_actor::type, typename as_actor::type> result; return result( as_actor::convert(cond), as_actor::convert(then)); } CondT cond; }; ////////////////////////////////// template inline if_gen if_(CondT const& cond) { return if_gen(cond); } /////////////////////////////////////////////////////////////////////////////// // // while_composite // // This composite has the form: // // while_(condition) // [ // statement // ] // // While the condition (an actor) evaluates to true, statement // (another actor) is executed. The result type of this is void. // Note the trailing underscore after while_. // /////////////////////////////////////////////////////////////////////////////// template struct while_composite { typedef while_composite self_t; template struct result { typedef void type; }; while_composite(CondT const& cond_, DoT const& do__) : cond(cond_), do_(do__) {} template void eval(TupleT const& args) const { while (cond.eval(args)) do_.eval(args); } CondT cond; DoT do_; }; ////////////////////////////////// template struct while_gen { while_gen(CondT const& cond_) : cond(cond_) {} template actor::type, typename as_actor::type> > operator[](DoT const& do_) const { typedef while_composite< typename as_actor::type, typename as_actor::type> result; return result( as_actor::convert(cond), as_actor::convert(do_)); } CondT cond; }; ////////////////////////////////// template inline while_gen while_(CondT const& cond) { return while_gen(cond); } /////////////////////////////////////////////////////////////////////////////// // // do_composite // // This composite has the form: // // do_ // [ // statement // ] // .while_(condition) // // While the condition (an actor) evaluates to true, statement // (another actor) is executed. The statement is executed at least // once. The result type of this is void. Note the trailing // underscore after do_ and the leading dot and the trailing // underscore before and after .while_. // /////////////////////////////////////////////////////////////////////////////// template struct do_composite { typedef do_composite self_t; template struct result { typedef void type; }; do_composite(DoT const& do__, CondT const& cond_) : do_(do__), cond(cond_) {} template void eval(TupleT const& args) const { do do_.eval(args); while (cond.eval(args)); } DoT do_; CondT cond; }; //////////////////////////////////// template struct do_gen2 { do_gen2(DoT const& do__) : do_(do__) {} template actor::type, typename as_actor::type> > while_(CondT const& cond) const { typedef do_composite< typename as_actor::type, typename as_actor::type> result; return result( as_actor::convert(do_), as_actor::convert(cond)); } DoT do_; }; //////////////////////////////////// struct do_gen { template do_gen2 operator[](DoT const& do_) const { return do_gen2(do_); } }; do_gen const do_ = do_gen(); /////////////////////////////////////////////////////////////////////////////// // // for_composite // // This statement has the form: // // for_(init, condition, step) // [ // statement // ] // // Where init, condition, step and statement are all actors. init // is executed once before entering the for-loop. The for-loop // exits once condition evaluates to false. At each loop iteration, // step and statement is called. The result of this statement is // void. Note the trailing underscore after for_. // /////////////////////////////////////////////////////////////////////////////// template struct for_composite { typedef composite self_t; template struct result { typedef void type; }; for_composite( InitT const& init_, CondT const& cond_, StepT const& step_, DoT const& do__) : init(init_), cond(cond_), step(step_), do_(do__) {} template void eval(TupleT const& args) const { for (init.eval(args); cond.eval(args); step.eval(args)) do_.eval(args); } InitT init; CondT cond; StepT step; DoT do_; // actors }; ////////////////////////////////// template struct for_gen { for_gen( InitT const& init_, CondT const& cond_, StepT const& step_) : init(init_), cond(cond_), step(step_) {} template actor::type, typename as_actor::type, typename as_actor::type, typename as_actor::type> > operator[](DoT const& do_) const { typedef for_composite< typename as_actor::type, typename as_actor::type, typename as_actor::type, typename as_actor::type> result; return result( as_actor::convert(init), as_actor::convert(cond), as_actor::convert(step), as_actor::convert(do_)); } InitT init; CondT cond; StepT step; }; ////////////////////////////////// template inline for_gen for_(InitT const& init, CondT const& cond, StepT const& step) { return for_gen(init, cond, step); } } // namespace phoenix #endif