1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
|
(* camlp5r *)
(* calc.ml,v *)
value g = Grammar.gcreate (Plexer.gmake ());
value e = Grammar.Entry.create g "expression";
EXTEND
e:
[ [ x = e; "+"; y = e -> x + y
| x = e; "-"; y = e -> x - y ]
| [ x = e; "*"; y = e -> x * y
| x = e; "/"; y = e -> x / y ]
| [ x = INT -> int_of_string x
| "("; x = e; ")" -> x ] ]
;
END;
open Printf;
if not Sys.interactive.val then
try
for i = 1 to Array.length Sys.argv - 1 do {
let r = Grammar.Entry.parse e (Stream.of_string Sys.argv.(i)) in
printf "%s = %d\n" Sys.argv.(i) r;
flush stdout;
}
with [ Ploc.Exc loc exc ->
Fmt.(pf stderr "%s%a@.%!" (Ploc.string_of_location loc) exn exc)
| exc -> Fmt.(pf stderr "%a@.%!" exn exc)
]
else ()
;
|
