My first post was remiss in not noting another important use of
blanks-substring detection, which is due originally to the late John Cocke.
The most important determinant of the performance of a translator--compiler,
interpreter, assembler, whatever--is the speed and efficiency with which it
eliminates insignificant blanks from source-program text.
I could wish things were otherwise. Symbol-table organization is certainly of
much greater interest, but it is also much less important.
Apart from its obvious usefulness in processing right-to-left text like that of
Arabic, Farsi, and Hebrew, the TRTR instruction is valuable for locating the
rightmost non-blank character in left-to-right text.
John Gilmore Ashland, MA 01721-1817 USA
