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3 points by akkartik 531 days ago | link | parent

Staring at these examples again, another thought occurs to me: do these macros cause multiple evaluation, or are the equivalences above just loose? Can anybody tell? I can't tell just from skimming the implementation.

If they're doing multiple evaluations they're a lot less useful than Paul Graham's original anaphoric macros even if they seem superficially more powerful/expressive.

3 points by i4cu 531 days ago | link

> do these macros cause multiple evaluation

from the read-me:

"Note that as of right now the symbols are replaced by copying in the expression it references, not by binding to a common variable. Hence not suitable for using with expressions that cause side-effects or involve a lot of computation. That will be changed soon."

I presume, by reading this, these expressions will be evaluated each time they are triggered within the operation, so the answer is - yes they will. But, as the read-me also suggests, this is a "WORK IN PROGRESS" and the author has stated intentions to assign variables, which would solve the issue.