Stas Boukarev stassats@gmail.com writes:
:|| is a valid symbol in CL, its name is an empty string, "", and it would be much more pleasant to use it for concatenation instead of :||.
The attached patch adds :|| operator.
The manual should be updated as well, stating that :|| can be used without escaping (and that all other |-containing operators should be escaped), but I'll leave that to someone more well-versed in the English language.