Quoth Keith Wright <[email protected]>: >> From: Sebastian Tennant <[email protected]> >>> Quoth Keith Wright <[email protected]>:
>>> I don't know what happens (in Guile), but I can tell >>> you what _should_ happen. (In my humble opinion as >>> a demi-god of semantics.) >> I'm trying to wrap my head around symbols, variables >> and names of variables. They seem to me to be three >> different things. > NB: I hate emoticons. The lack of a smiley face does > not imply seriousness. This sort of thing has been > puzzling a lot of people for a long time. In particular, > I published a paper about it some 25 years ago, but have > since decided that I don't know enough to be publishing. > That's why it's fun to rave on the mailing list. So... you're not a demi-god of semantics. Damn. I told all my friends that you were. > I almost understand something about symbols and variables, but the > _name_ of a variable is not a technical term. I don't name variables, > I just call them "this variable" or "that variable", or sometimes > describe them as the "local variable |foo|". >>> But you are asking the wrong question. Ask not what happens when a >>> symbol is defined, ask what you can do to make the macro define an >>> unquoted variable. >> Answer: Pass it an unquoted variable. >> >> Is that the answer you expected? > I am not sure I expected it, but it makes me feel good to know that it > works. Pleased to be of service. >> My semantic point is that the first argument to definer (above) is >> not a symbol and it's not a variable (an unbound variable error would >> be thrown if it was), so in the context of the first agument to >> define there is a third data type; 'variable name'. > > I am quite sure that it _is_ a variable, because the Scheme report, in > the section on Variable Definitions, says: > > (define <variable> <expression>) > ...define binds <variable> to a new location... > > you yourself say "pass it an unquoted variable". I thought about this obvious contradiction but decided the pith outweighed the loss. > "The name of the song is called 'Haddocks' eyes'." "Oh, that's the > name of the song, is it?" Alice said. "No, you don't understand," > the Knight said, looking a little vexed. "That's what the name is > _called_." I wonder what song it was to which Haddock's Eyes referred. Sebastian
