Function: readvec
Section: programming/specific
C-Name: gp_readvec_file
Prototype: D"",s,
Help: readvec({filename}): create a vector whose components are the evaluation
 of all the expressions found in the input file filename.
Description:
 (str):gen      gp_readvec_file($1)
Doc: reads in the file
 \var{filename} (subject to string expansion). If \var{filename} is
 omitted, re-reads the last file that was fed into \kbd{gp}. The return
 value is a vector whose components are the evaluation of all sequences
 of instructions contained in the file. For instance, if \var{file} contains
 \bprog
 1
 2
 3
 @eprog\noindent
 then we will get:
 \bprog
 ? \r a
 %1 = 1
 %2 = 2
 %3 = 3
 ? read(a)
 %4 = 3
 ? readvec(a)
 %5 = [1, 2, 3]
 @eprog
 In general a sequence is just a single line, but as usual braces and
 \kbd{\bs} may be used to enter multiline sequences.
Variant: The underlying library function
 \fun{GEN}{gp_readvec_stream}{FILE *f} is usually more flexible.
