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soFromBeginning

soFromBeginning = 0

Example​

function MoveToByte(Stream: TStream; Offset: Int64): Int64;
begin
  Result := Stream.Seek(Offset, soFromBeginning);
end;

Usage​

soFromBeginning makes TStream.Seek interpret its signed Int64 offset as an absolute byte position from the start of the stream.

Additional Technical Info​

soFromBeginning makes TStream.Seek treat Offset as the new absolute byte position. For ordinary seekable streams, the calculation is new position = Offset, where byte 0 is the start.

Velox registers this legacy name as a LongInt constant and exposes Seek(Offset: Int64; Origin: Word): Int64. Current Delphi internally maps ordinal 0 to typed soBeginning. The modern TSeekOrigin type/name is not part of the generated script surface.

Boundaries

  • A negative absolute position is invalid for normal memory/file streams and can fail immediately or make later operations fail according to the descendant.
  • Seeking past Size can be allowed without immediately changing Size. A later write can extend the stream and create a descendant/filesystem-specific gap.
  • Seek returns the new Int64 position. Keep that result for offsets outside the script-visible Position property's LongInt range.
  • Seeking moves shared mutable cursor state; it does not read, write, reserve or synchronize bytes.

Assigning Position also seeks from the beginning, but the direct method exposes the wider offset/result contract. Stream ownership is unchanged.

The example is source-reviewed only; no stream cursor was moved.

External references

Created 2026-07-15