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Diffstat (limited to 'include/serd/cursor.h')
-rw-r--r-- | include/serd/cursor.h | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/include/serd/cursor.h b/include/serd/cursor.h new file mode 100644 index 00000000..eba88ca7 --- /dev/null +++ b/include/serd/cursor.h @@ -0,0 +1,83 @@ +// Copyright 2011-2022 David Robillard <d@drobilla.net> +// SPDX-License-Identifier: ISC + +#ifndef SERD_CURSOR_H +#define SERD_CURSOR_H + +#include "serd/attributes.h" +#include "serd/memory.h" +#include "serd/statement.h" +#include "serd/status.h" +#include "zix/attributes.h" + +#include <stdbool.h> + +SERD_BEGIN_DECLS + +/** + @defgroup serd_cursor Cursor + @ingroup serd_storage + @{ +*/ + +/** + A cursor that iterates over statements in a model. + + A cursor is a smart iterator that visits all statements that match a + pattern. +*/ +typedef struct SerdCursorImpl SerdCursor; + +/// Return a new copy of `cursor` +SERD_API SerdCursor* ZIX_ALLOCATED +serd_cursor_copy(SerdAllocator* ZIX_NULLABLE allocator, + const SerdCursor* ZIX_NULLABLE cursor); + +/// Return the statement pointed to by `cursor` +SERD_API const SerdStatement* ZIX_NULLABLE +serd_cursor_get(const SerdCursor* ZIX_NULLABLE cursor); + +/** + Increment cursor to point to the next statement. + + Null is treated like an end cursor. + + @return Failure if `cursor` was already at the end. +*/ +SERD_API SerdStatus +serd_cursor_advance(SerdCursor* ZIX_NULLABLE cursor); + +/** + Return true if the cursor has reached its end. + + Null is treated like an end cursor. +*/ +SERD_PURE_API bool +serd_cursor_is_end(const SerdCursor* ZIX_NULLABLE cursor); + +/** + Return true iff `lhs` equals `rhs`. + + Two cursors are equivalent if they point to the same statement in the same + index in the same model, or are both the end of the same model. Note that + two cursors can point to the same statement but not be equivalent, since + they may have reached the statement via different indices. + + Null is treated like an end cursor. +*/ +SERD_PURE_API bool +serd_cursor_equals(const SerdCursor* ZIX_NULLABLE lhs, + const SerdCursor* ZIX_NULLABLE rhs); + +/// Free `cursor` +SERD_API void +serd_cursor_free(SerdAllocator* ZIX_NULLABLE allocator, + SerdCursor* ZIX_NULLABLE cursor); + +/** + @} +*/ + +SERD_END_DECLS + +#endif // SERD_CURSOR_H |