| 1 | #ifndef ITERATOR_H |
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| 2 | #define ITERATOR_H |
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| 3 | |
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| 4 | #include "iostream.h" |
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| 5 | |
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| 6 | // An iterator can be used to traverse a data structure. |
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| 7 | context iterator( type iterator_type, type elt_type ) { |
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| 8 | // point to the next element |
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| 9 | // iterator_type ?++( iterator_type * ); |
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| 10 | iterator_type ++?( iterator_type * ); |
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| 11 | iterator_type --?( iterator_type * ); |
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| 12 | |
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| 13 | // can be tested for equality with other iterators |
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| 14 | int ?==?( iterator_type, iterator_type ); |
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| 15 | int ?!=?( iterator_type, iterator_type ); |
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| 16 | |
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| 17 | // dereference to get the pointed-at element |
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| 18 | lvalue elt_type *?( iterator_type ); |
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| 19 | }; |
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| 20 | |
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| 21 | context iterator_for( type iterator_type, type collection_type, type elt_type | iterator( iterator_type, elt_type ) ) { |
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| 22 | // [ iterator_type begin, iterator_type end ] get_iterators( collection_type ); |
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| 23 | iterator_type begin( collection_type ); |
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| 24 | iterator_type end( collection_type ); |
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| 25 | }; |
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| 26 | |
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| 27 | forall( type iterator_type, type elt_type | iterator( iterator_type, elt_type ) ) |
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| 28 | void for_each( iterator_type begin, iterator_type end, void (*func)( elt_type ) ); |
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| 29 | |
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| 30 | // writes the range [begin, end) to the given stream |
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| 31 | forall( type elt_type | writeable( elt_type ), |
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| 32 | type iterator_type | iterator( iterator_type, elt_type ), |
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| 33 | dtype os_type | ostream( os_type ) ) |
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| 34 | void write_all( iterator_type begin, iterator_type end, os_type *os ); |
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| 35 | |
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| 36 | forall( type elt_type | writeable( elt_type ), |
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| 37 | type iterator_type | iterator( iterator_type, elt_type ), |
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| 38 | dtype os_type | ostream( os_type ) ) |
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| 39 | void write_reverse( iterator_type begin, iterator_type end, os_type *os ); |
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| 40 | |
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| 41 | #endif // ITERATOR_H |
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