"sequence" element and pmap

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Imported from previous forum

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I have a question about whether a “pmap” is required for the “sequence” in the following example:

The field “exponent” doesn’t require a “pmap” bit, because it’s operation is “delta”.

Since the field “decimal” is optional, “exponent” is optional. The presence of pmap bit for “mantissa” depends on the value of “exponent”.

But before encoding/decoding the “sequence”, we need to know if it needs a pmap or not.

Thanks a lot for your help.

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This sequence will always have a presence map since at least on of the instructions within the sequence requires a bit in the presence map. However, this particular bit will not be accessed in every instance since the processing of the mantissa depends on whether the exponent is NULL or not.

More general: the existance of a presence map can always be statically deduced from the template definition and will never depend on the encoded data.

/David

I have a question about whether a “pmap” is required for the “sequence”
in the following example:

The field “exponent” doesn’t require a “pmap” bit, because it’s
operation is “delta”.

Since the field “decimal” is optional, “exponent” is optional. The
presence of pmap bit for “mantissa” depends on the value of “exponent”.

But before encoding/decoding the “sequence”, we need to know if it needs
a pmap or not.

Thanks a lot for your help.