source: libcfa/src/bits/stack.hfa@ ddcedfe

#pragma once

#include "collection.hfa"

forall( dtype T ) {
        struct Stack {
                inline Collection;                                                              // Plan 9 inheritance
        };

        inline {
                // wrappers to make Collection have T
                T * head( Stack(T) & s ) with( s ) {
                        return (T *)head( (Collection &)s );
                } // post: empty() & head() == 0 | !empty() & head() in *this

                bool empty( Stack(T) & s ) with( s ) {                  // 0 <=> *this contains no elements
                        return empty( (Collection &)s );
                }

                T *& Next( T * n ) {
                        return (T *)Next( (Colable *)n );
                }

                T * Root( Stack(T) & s ) with( s ) {
                        return (T *)root;
                }

                void ?{}( Stack(T) &, const Stack(T) & ) = void; // no copy
                Stack(T) & ?=?( const Stack(T) & ) = void;              // no assignment

                void ?{}( Stack(T) & s ) with( s ) {
                        ((Collection &)s){};
                } // post: empty()

                T * top( Stack(T) & s ) with( s ) {
                        return head( s );
                }

                void addHead( Stack(T) & s, T * n ) with( s ) {
#ifdef __CFA_DEBUG__
                        if ( listed( (Colable &)(*n) ) ) abort( "(Stack &)%p.addHead( %p ) : Node is already on another list.", &s, n );
#endif // __CFA_DEBUG__
                        Next( n ) = Root( s ) ? Root( s ) : n;
                        root = n;
                }

                void add( Stack(T) & s, T * n ) with( s ) {
                        addHead( s, n );
                }

                void push( Stack(T) & s, T * n ) with( s ) {
                        addHead( s, n );
                }

                T * drop( Stack(T) & s ) with( s ) {
                        T * t = head( s );
                        if ( root ) {
                                root = ( T *)Next(root);
                                if ( Root( s ) == t ) root = 0p;                // only one element ?
                                Next( t ) = 0p;
                        } // if
                        return t;
                }

                T * pop( Stack(T) & s ) with( s ) {
                        return drop( s );
                }
        } // distribution
} // distribution


forall( dtype T ) {
        struct StackIter {
                inline ColIter;                                                                 // Plan 9 inheritance
        };      

        inline {
                // wrappers to make ColIter have T
                T * Curr( StackIter(T) & si ) with( si ) {
                        return (T *)curr;
                }

                void ?{}( StackIter(T) & si ) with( si ) {
                        ((ColIter &)si){};
                } // post: curr == 0p

                // create an iterator active in Stack s
                void ?{}( StackIter(T) & si, Stack(T) & s ) with( si ) {
                        curr = head( s );
                } // post: curr = {e in s}

                void ?{}( StackIter(T) & si, T * start ) with( si ) {
                        curr = start;
                } // post: curr = {e in s}

                // make existing iterator active in Stack q
                void over( StackIter(T) & si, Stack(T) & s ) with( si ) {
                        curr = head( s );
                } // post: curr = {e in s}

                bool ?>>?( StackIter(T) & si, T && tp ) with( si ) {
                        if ( curr ) {
                                &tp = Curr( si );
                                T * n = Next( Curr( si ) );
                                curr = (n == Curr( si ) ) ? 0p : n;
                        } else &tp = 0p;
                        return &tp != 0p;
                }
        } // distribution
} // distribution

// Local Variables: //
// compile-command: "make install" //
// End: //