Coda by Ian Macalinao
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    Function postOffsetTypeNode

    • After serialising the wrapped type, advance the cursor by offset bytes interpreted via the chosen strategy.

      Since the offset is applied after the wrapped type runs, this node is useful to move the cursor around once the wrapped type has been processed. See preOffsetTypeNode for the opposite behaviour.

      The strategies below are illustrated against the following buffer: the 99 byte represents the encoded value of the wrapped type and the FF byte represents the next bytes to be encoded after it, in order to show the post cursor position.

      0x00000099FF000000;
      | └-- Initial post-offset
      └-- Pre-offset

      relative — the cursor is moved to the right by the provided offset. A negative offset moves it to the left instead.

      offset = 2
      0x000000990000FF00;
      └-- Post-offset

      offset = -2
      0x0000FF9900000000;
      └-- Post-offset

      absolute — the cursor is moved to an absolute position in the buffer. A negative offset moves it backwards from the end of the buffer.

      offset = 0
      0xFF00009900000000;
      └-- Post-offset

      offset = -2
      0x000000990000FF00;
      └-- Post-offset

      padded — the cursor is moved to the right by the provided offset and the buffer size is increased by the offset amount, allowing padding bytes to be added. Reciprocally, a negative offset moves the cursor to the left and decreases the buffer size.

      offset = 2
      0x000000990000FF000000; <- Size = 10 (initially 8)
      └-- Post-offset

      offset = -2
      0x0000FF990000; <- Size = 6 (initially 8)
      └-- Post-offset

      preOffset — the cursor is moved to the right of the pre-offset — i.e. where the wrapped type started — by the provided offset. A negative offset moves it to the left of the pre-offset instead.

      offset = 2
      0x0000009900FF0000;
      | └-- Post-offset = Pre-offset + 2
      └-- Pre-offset

      offset = -2
      0x00FF009900000000;
      | └-- Pre-offset
      └-- Post-offset = Pre-offset - 2
      Important

      Some type nodes affect the buffer that is available to us: depending on where we are in the type tree, we may not have access to the entire buffer. For instance, inside a fixedSizeTypeNode, the buffer is truncated or padded to match the provided fixed size once the wrapped content has been serialised — we are essentially "boxed" into a sub-buffer, and that sub-buffer is the one affected by the absolute strategy. The type nodes that create sub-buffers are: fixedSizeTypeNode, sentinelTypeNode, and sizePrefixTypeNode.

      Type Parameters

      Parameters

      Returns PostOffsetTypeNode<TType>