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rose-ash/lib/ocaml/baseline/bracket_match.ml
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ocaml: phase 5.1 bracket_match.ml baseline (5/9 balanced strings)
Stack-based multi-bracket parenthesis matching for ( [ { ) ] }.
Non-bracket chars are skipped (treated as content).

Tests:
  ()           yes
  [{()}]       yes
  ({[}])       no  (mismatched closer)
  ""           yes
  ((           no  (unclosed)
  ()[](){}     yes
  (a(b)c)      yes  (a/b/c skipped)
  (()          no
  ])           no
                 5 balanced

Body uses begin/end-wrapped match inside while:

  else if c = ')' || c = ']' || c = '}' then begin
    match !stack with
    | [] -> ok := false
    | top :: rest ->
      let pair =
        (c = ')' && top = '(') ||
        (c = ']' && top = '[') ||
        (c = '}' && top = '{')
      in
      if pair then stack := rest else ok := false
  end

Tests side-effecting match arms inside while body, ref-of-list as
stack, multi-char pairing dispatch.

174 baseline programs total.
2026-05-11 01:02:59 +00:00

33 lines
807 B
OCaml

let bracket_match s =
let n = String.length s in
let stack = ref [] in
let ok = ref true in
let i = ref 0 in
while !ok && !i < n do
let c = s.[!i] in
if c = '(' || c = '[' || c = '{' then
stack := c :: !stack
else if c = ')' || c = ']' || c = '}' then begin
match !stack with
| [] -> ok := false
| top :: rest ->
let pair =
(c = ')' && top = '(') ||
(c = ']' && top = '[') ||
(c = '}' && top = '{')
in
if pair then stack := rest else ok := false
end;
i := !i + 1
done;
if !ok && !stack = [] then 1 else 0
;;
let strings = ["()"; "[{()}]"; "({[}])"; ""; "(("; "()[](){}"; "(a(b)c)"; "(()"; "])"] in
let count = ref 0 in
List.iter (fun s ->
count := !count + bracket_match s
) strings;
!count