dorai@titan.rice.edu (Dorai Sitaram) (04/01/89)
I'm asking this for a friend. He needs to know how to make ... (3 consecutive dots) a symbol in CL, so that he can use it as an ellipsis(sp?) symbol as in Scheme's extend-syntax. He is currently using *** and/or ___, but these violate his aesthetic sensibilities. Thanks. --dorai
barmar@think.COM (Barry Margolin) (04/01/89)
In article <2997@kalliope.rice.edu> dorai@titan.rice.edu (Dorai Sitaram) writes: >He needs to know how to make ... (3 consecutive dots) a symbol in CL, Any sequence of characters will be read as a symbol if it is enclosed in vertical bars, so he can type |...| to get a symbol whose name is three periods. I believe \... may also work, but I'm not sure. If he wants a way to permit it to be typed unadorned, I don't think that can be done without breaking other things. He can use SET-SYNTAX-FROM-CHAR to cause it to be treated the same as an alphabetic character, but then it would lose its treatment as the consing dot and as the decimal point in numbers. By the way, the reason that ... is required to signal an error is that it is generated when the printer abbreviates output due to *PRINT-LENGTH*. The intent is to guarantee that if output was abbreviated when sent to a file, and an attempt is made to read that file, the loss of information will result in an error being signalled. If your friend manages to make ... read as a symbol, how does he propose to deal with the ambiguity it then creates due to the above? Barry Margolin Thinking Machines Corp. barmar@think.com {uunet,harvard}!think!barmar