RosettaCodeData/Task/Balanced-brackets/Component-Pascal/balanced-brackets.pas

MODULE Brackets;
IMPORT StdLog, Args, Stacks (* See Task Stacks *);
TYPE

    Character = POINTER TO RECORD (Stacks.Object)
        c: CHAR
    END;

PROCEDURE NewCharacter(c: CHAR): Character;
VAR
    n: Character;
BEGIN
    NEW(n);n.c:= c;RETURN n
END NewCharacter;

PROCEDURE (c: Character) Show*;
BEGIN
    StdLog.String("Character(");StdLog.Char(c.c);StdLog.String(");");StdLog.Ln
END Show;

PROCEDURE CheckBalance(str: ARRAY OF CHAR): BOOLEAN;
VAR
    s: Stacks.Stack;
    n,x: ANYPTR;
    i: INTEGER;
    c : CHAR;
BEGIN
    i := 0; s := Stacks.NewStack();
    WHILE (i < LEN(str$)) & (~Args.IsBlank(str[i])) & (str[i] # 0X) DO
        IF s.Empty() THEN
            s.Push(NewCharacter(str[i]));
        ELSE
            n := s.top.data;
            WITH
                n :  Character DO
                IF (str[i] = ']')& (n.c = '[') THEN
                    x := s.Pop();
                ELSE
                    s.Push(NewCharacter(str[i]))
                END;
            ELSE RETURN FALSE;
            END;
        END;
        INC(i)
    END;
    RETURN s.Empty();
END CheckBalance;

PROCEDURE Do*;
VAR
    p : Args.Params;
    i: INTEGER;
BEGIN
    Args.Get(p); (* Get Params *)
    FOR i := 0 TO p.argc - 1 DO
        StdLog.String(p.args[i] + ":>");StdLog.Bool(CheckBalance(p.args[i]));StdLog.Ln
    END
END Do;

END Brackets.