nreplace, nreplace_equal
nreplace, nreplace_equal — replace elements in a list.
Syntax
nreplace (new_s_exp, old_s_exp, list)
nreplace_equal (new_s_exp, old_s_exp, list)
Arguments
- new_s_exp
- The new expression to be inserted into
the list.
- old_s_exp
- The expression in the list to be
replaced.
- list
- A list.
Returns
The list, with all occurrences of
old_s_exp destructively replaced by
new_s_exp.
Description
nreplace traverses the
list, replacing any element which
is eq to
old_s_exp with
new_s_exp.
nreplace_equal uses
equal as its comparison function.
Example
Gamma> R = list (#f, nil, 5, #ftg);
(f nil 5 ftg)
Gamma> nreplace(#h, #ftg, R);
(f nil 5 h)
Gamma> x = list(1,2,3,1,6,7);
(1 2 3 1 6 7)
Gamma> nreplace(4,1,x);
(1 2 3 1 6 7)
Gamma> nreplace_equal(4,1,x);
(4 2 3 4 6 7)
Gamma> x;
(4 2 3 4 6 7)
Gamma>
