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How-To film · 54

Parse, don’t split

Change a valid arithmetic expression to invalid syntax and watch Grid return structured rejection evidence instead of turning the parse into a model error.

47 secCaptions + transcriptGrid 0.63.2

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  1. Splitting finds separators. Parsers explain syntax.
  2. This arithmetic grammar accepts the expression as a complete parse.
  3. Named capture returns three numbers in source order.
  4. Now change the source to two plus star three.
  5. The parse fails, captures fall to zero, and the model stays healthy.
  6. Grid reports the exact rejection: zero-based offset four, where it found the star.
  7. Keep rejection structured.

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