Data compressor utilizing switched input coincidence elements

Data compression apparatus for compressing an input stream of data characters into an output stream of compressed codes, comprising

• a plurality of coincidence elements corresponding to a respective plurality of codes to be assigned to strings, a string being comprised of a prefix string of at least one of said data characters followed by an extension character, a prefix string having a prefix code associated therewith,
• a coincidence element providing a coincidence output and having a prefix code input and a character input for enabling the coincidence element to energize the coincidence output thereof upon coincidental energization of the inputs thereof so that energization of a coincidence output of a coincidence element provides a representation of the code corresponding thereto,
• first coupling means for selectively coupling the representations of codes corresponding to the coincidence elements to the prefix code inputs of the coincidence elements,
• second coupling means for selectively coupling representations of data characters fetched from said input stream to the character inputs of the coincidence elements,
• means for sequentially fetching data characters from said input stream so as to sequentially enable coincidence elements until a last data character is fetched that does not result in an enabled coincidence element, and
• means for outputting the code corresponding to the last enabled coincidence element, thereby providing said stream of compressed codes.