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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Michael Montague writes: > Maybe I am being a heretic, but what are the benefits of the SRE syntax? It reflects the tree-like structure of regular expressions as a data type. What you're calling the "traditional syntax" flattens that structure into a linear string, which the reader has to parse in order to recover the structure. The SRE syntax also supports modular design and component reuse better than the traditional syntax. Scheme's built-in binding mechanisms can be used to give names to useful and interesting subexpressions. Such subexpressions can be tested independently. The traditional syntax fails in all these respects, because the only intuitive way to combine regular expressions in that syntax is by string concatenation, which is error-prone (particularly, but not exclusively, when there are submatch assignments) and comparatively inflexible. > The beginning of the rational notes that "regular expressions are the > lingua franca of string matching today". Part of that lingua franca is > the traditional syntax of regular expressions. Yes, it's a sad story. If the tool-builders who implemented Unix had thought carefully about the traditions relating to regular expressions that the designers of SNOBOL4 had already tried to establish, we wouldn't find it necessary to reinvent them every few years. One weeps to think of all the agonizing, needless labor that programmers have done over the years in trying to understand and debug regular expressions in traditional syntax. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Processed by Mailcrypt 3.5.9 <http://mailcrypt.sourceforge.net/> iQIcBAEBAgAGBQJSXvBVAAoJEG4s3o5S5qkZj+wP/0mdyfsL4P0ory1vh0TlXQbg iFKkLqyK7GKzONdqZtvLr2YHxb6t12aFhv3pMsCIQ17OvXhbP6kAxEe2WhS3EQDB ORIEGsnzarojyyt+a9h2td2KkuUKtlyijx5wndDzh7aBQr3Thhl8DrJofwuCK/0F mHE6hJU+6bhXJnxB9KQ6GhK0bOaPUZyh286gzR77P3j4ZKsVCjbZ1CtGsxNHUodF BpeTb4DtotR+3/nwv2A4RM55xTjJTinMu+tFqjlxU/jpvKBwQuVq7zNH8q+xz/MV mxmsJbNg+Uvabeo2x6S6XkM61dcFgPyNpwGB7MjAdjppKBwmYR0MGWn77Sy2xHK6 ZstN6dPpMZhHEL2vm+JRhwgpSjPTQMxYUoZsZWoBB1KJJh9T5tbhU3hsNmBuDh7a 5EbNHYzmkzEN9x/2V45UjKk5RWwuzrXCEkQaIULhPguajiCnQ0bwm46jBO3xBj7Y CqBx5UtVFAvEaciGbfbhB4pElZq1fF/dYtag3rbzmbD2xnKbJbR9GrJ3hNbnmSV7 8WAPfhn2K1faEfk5t5Aikz0g17Ufw19nmIdpKYTkdi+pOVk47k47cmJKO07TV5cv Uq3ih5M7JekgiMqG+N8uGyRkwbcPphkbssm/o/7yN3qfdDXK2gKND3I3VeNUeQvU qWlczSKu8IyiOtp7kX4T =T7lt -----END PGP SIGNATURE-----