Encoded string processing

A method comprising:

• setting, by a processor, a shadow pointer to a first shadow unit of a plurality of shadow units of a shadow array;
• setting, by the processor, a string pointer to a first code unit of a processed string encoding characters via a plurality of code units, including the first code unit, within an encoding scheme, the shadow array corresponding to the processed string;
• determining, by the processor, whether the shadow unit referenced by the shadow pointer indicates that one or more code units of the processed string beginning with the code unit referenced by the string pointer are valid within the encoding scheme, or whether the shadow unit referenced by the shadow pointer indicates that the code unit referenced by the string pointer is invalid within the encoding scheme;
• in response to determining that the shadow unit referenced by the shadow pointer indicates that the one or more code units of the processed string beginning with the code unit referenced by the string pointer are valid:
• starting at the code unit referenced by the string pointer, processing, by the processor, the one or more code units that encode a single character;
• appending, by the processor, the one or more code units as have been processed to an original string;
• advancing, by the processor, the string pointer to the code unit of the processed string following the one or more code units;
• and
• advancing, by the processor, the shadow pointer to a next shadow unit within the shadow array.

A system comprising;

• a storage device to store:
• an original string encoding characters via a plurality of code units within a encoding scheme;
• a shadow array corresponding to the original string and having a plurality of shadow units, each shadow unit indicating whether a corresponding code unit within the original string is invalid within the encoding scheme or whether corresponding one or more code units within the original string are valid within the encoding scheme;
• a processed string corresponding to the original string;
• a processor;
• and
• a memory storing program code executable by the processor to process the original string to generate the shadow array and the processed string.