Thanks, I understand it now. Racket is not Scheme but if I were to strictly follow the R6RS, then both should fail, since both characters and booleans require delimiters.
On Tue, Feb 1, 2011 at 9:35 AM, Matthew Flatt <[email protected]> wrote: > Different Scheme variants vary in whether `#t' and `#f' must be > followed by a delimiter. R6RS, for example, requires a delimiter. > > Prior to version 5.0.2, Racket did not require a delimiter, but now it > does (while `#true' and `#false' are also allowed as booleans). > > At Tue, 1 Feb 2011 08:59:04 -0600, qld3303 wrote: > > Hello, > > I'm a beginner trying to write a simple Scheme interpreter to help > > understand Racket better. I try to mimic the results from the repl as > best > > possible however in some cases I'm not sure how to reproduce them, this > > being one such case. It seems to imply that an identifier or something > > other than a boolean could begin with #t but I'm not sure. I tried this > > using Guile and got the opposite results: > > guile> (+ 3 1)#t+ > > 4 > > #t > > #<primitive-generic +> > > guile> (+ 3 1)#\t+ > > 4 > > ERROR: In procedure scm_lreadr: > > ERROR: #<unknown port>:2:1: unknown character name t+ > > ABORT: (read-error) > > > > Currently, my naive repl will work for both characters and booleans but > > perhaps it shouldn't? > > > > Thanks > > > > On Mon, Jan 31, 2011 at 9:13 PM, qld3303 <[email protected]> wrote: > > > > > I'm not clear as to why the following occurs: > > > > > > > (+ 3 1)#t+ > > > 4 > > > readline-input::183: read: bad syntax `#t+' > > > > > > > (+ 3 1)#\t+ > > > 4 > > > #\t > > > #<procedure:+> > > > > > > Why doesn't it recognize that #t is a boolean value? > > > > > _________________________________________________ > > For list-related administrative tasks: > > http://lists.racket-lang.org/listinfo/users >
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