1 /**

     2 	@name String

     3 	@class Additions to the core string object.

     4 */

     5 

     6 /** @author Steven Levithan, released as public domain. */

     7 String.prototype.trim = function() {

     8 	var str = this.replace(/^\s+/, '');

     9 	for (var i = str.length - 1; i >= 0; i--) {

    10 		if (/\S/.test(str.charAt(i))) {

    11 			str = str.substring(0, i + 1);

    12 			break;

    13 		}

    14 	}

    15 	return str;

    16 }

    17 /*t:

    18 	plan(6, "Testing String.prototype.trim.");

    19 	

    20 	var s = "   a bc   ".trim();

    21 	is(s, "a bc", "multiple spaces front and back are trimmed.");

    22 

    23 	s = "a bc\n\n".trim();

    24 	is(s, "a bc", "newlines only in back are trimmed.");

    25 	

    26 	s = "\ta bc".trim();

    27 	is(s, "a bc", "tabs only in front are trimmed.");

    28 	

    29 	s = "\n \t".trim();

    30 	is(s, "", "an all-space string is trimmed to empty.");

    31 	

    32 	s = "a b\nc".trim();

    33 	is(s, "a b\nc", "a string with no spaces in front or back is trimmed to itself.");

    34 	

    35 	s = "".trim();

    36 	is(s, "", "an empty string is trimmed to empty.");

    37 

    38 */

    39 

    40 String.prototype.balance = function(open, close) {

    41 	var i = 0;

    42 	while (this.charAt(i) != open) {

    43 		if (i == this.length) return [-1, -1];

    44 		i++;

    45 	}

    46 	

    47 	var j = i+1;

    48 	var balance = 1;

    49 	while (j < this.length) {

    50 		if (this.charAt(j) == open) balance++;

    51 		if (this.charAt(j) == close) balance--;

    52 		if (balance == 0) break;

    53 		j++;

    54 		if (j == this.length) return [-1, -1];

    55 	}

    56 	

    57 	return [i, j];

    58 }

    59 /*t:

    60 	plan(16, "Testing String.prototype.balance.");

    61 	

    62 	var s = "{abc}".balance("{","}");

    63 	is(s[0], 0, "opener in first is found.");

    64 	is(s[1], 4, "closer in last is found.");

    65 	

    66 	s = "ab{c}de".balance("{","}");

    67 	is(s[0], 2, "opener in middle is found.");

    68 	is(s[1], 4, "closer in middle is found.");

    69 	

    70 	s = "a{b{c}de}f".balance("{","}");

    71 	is(s[0], 1, "nested opener is found.");

    72 	is(s[1], 8, "nested closer is found.");

    73 	

    74 	s = "{}".balance("{","}");

    75 	is(s[0], 0, "opener with no content is found.");

    76 	is(s[1], 1, "closer with no content is found.");

    77 	

    78 	s = "".balance("{","}");

    79 	is(s[0], -1, "empty string opener is -1.");

    80 	is(s[1], -1, "empty string closer is -1.");

    81 	

    82 	s = "{abc".balance("{","}");

    83 	is(s[0], -1, "opener with no closer returns -1.");

    84 	is(s[1], -1, "no closer returns -1.");

    85 	

    86 	s = "abc".balance("{","}");

    87 	is(s[0], -1, "no opener or closer returns -1 for opener.");

    88 	is(s[1], -1, "no opener or closer returns -1 for closer.");

    89 	

    90 	s = "a<bc}de".balance("<","}");

    91 	is(s[0], 1, "unmatching opener is found.");

    92 	is(s[1], 4, "unmatching closer is found.");

    93 */