On Sun, Feb 10, 2019 at 11:56 PM Bradley Lucier lucier@math.purdue.edu wrote:
“filter” is not part of the R4RS or R5RS scheme standards, which Gambit
implements. It appears that Marc is rapidly adding routines to Gambit to make it R7RS compliant, but I don’t see a “filter” routine in R7RS-small.
“Filter” is implemented in SRFI-1, and there is port of SRFI-1 to Gambit in the “Dumping Grounds”:
Right. The only SRFI-1 procedures added to R7RS-small are `make-list` and `list-copy`, based on the corresponding vector and string procedures. In addition, some others were slightly changed for SRFI 1 compatibility: e.g. R7RS-small `map` is specified to stop when one of the list arguments is exhausted, whereas in R5RS it was an error to provide lists of different lengths.