Benchmarking various means of collapsing a readable triple-quoted string into a single line appropriate as a portion of a URI.

Main.scala

object Main extends testing.Benchmark {

  val r = """[\r\n\s]""".r

  val s = """
    | Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod
    | tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim
    | veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea
    | commodo consequat. Duis aute irure dolor in reprehenderit in voluptate
    | velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat
    | cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
    """

  def collapseMargin(input: String): String = {
    input.lines.foldLeft(new StringBuilder(input.size)) { (buffer, line) =>
      val len = line.length

      var startIndex = 0
      var endIndex = len

      while (startIndex < len && line.charAt(startIndex) <= ' ') startIndex += 1
      while (endIndex > len && line.charAt(endIndex - 1) <= ' ') endIndex -= 1

      buffer append ' ' append line.substring(startIndex, endIndex)
    }.deleteCharAt(0).mkString
  }

  def run = {
    // r replaceAllIn(s.stripMargin, " ")
    s.stripMargin.lines.map(_.trim()).mkString(" ")
    // collapseMargin(s)
  }
}

results.txt

CACHED REGEX:

  val r = """[\r\n\s]""".r
  r replaceAllIn(s.stripMargin, " ")

> run 100 10
[info] Running Foo 100 10
Foo$	1	1	0	1	0	1	1	0	0	0	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	1	1	0	1	1	0	0	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	0	0	1	0	0	0	0	0	1	0	0	0	0	0	1	1	1	0	0	0	1	0	0	0	0	1	0	0	0
[success] Total time: 5 s, completed Jan 23, 2015 12:53:58 PM
> run 100 100
[info] Running Foo 100 100
Foo$	1	1	1	1	1	1	1	2	1	1	1	1	2	2	1	1	1	1	1	1	1	1	1	1	1	2	1	1	1	1	1	2	1	1	1	1	1	1	1	1	1	1	1	2	1	1	1	1	2	1	1	1	1	1	1	1	1	1	2	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	2	1	1	1	1	1	1	1	1	2	1	1	1	1	1	1	1	1	1
[success] Total time: 5 s, completed Jan 23, 2015 12:54:05 PM
> run 100 1000
[info] Running Foo 100 1000
Foo$	11	11	11	10	11	10	10	11	11	10	11	11	11	11	11	11	11	11	11	11	10	11	11	11	11	11	11	11	13	10	11	11	10	11	10	11	11	11	11	11	11	10	11	10	11	11	10	11	17	10	11	10	10	10	11	11	11	11	11	11	11	11	11	10	10	11	11	11	10	11	11	11	10	11	11	11	11	11	11	10	11	10	11	11	11	10	11	11	11	11	11	11	11	10	10	11	11	11	11	11
[success] Total time: 6 s, completed Jan 23, 2015 12:54:13 PM
> run 100 10000
[info] Running Foo 100 10000
Foo$	105	109	107	108	107	109	108	109	107	110	107	108	108	11	108	107	107	108	107	107	108	107	107	107	117	108	107	107	12	108	108	107	115	108	108	108	116	107	109	107	118	107	108	10	117	108	107	108	118	108	108	107	120	108	107	107	116	108	10	107	118	107	107	108	117	107	107	107	118	108	107	107	117	10	108	109	121	108	108	107	108	107	108	108	108	107	108	107	10	107	107	107	108	107	107	108	108	107	108	113
[success] Total time: 16 s, completed Jan 23, 2015 12:54:32 PM
> run 100 100000
[info] Running Foo 100 100000
Foo$	1073	1098	1106	1106	1106	1106	1105	1134	1104	1115	1107	1195	1189	1176	1114	1117	1099	1106	1115	1104	1108	1120	1105	1101	1107	1104	1106	1136	1117	1097	1103	1118	1115	1107	1108	1111	1096	1110	1104	1113	1107	1108	1097	1098	1107	1106	1106	1107	1103	1106	1110	1117	1109	1106	1112	1106	1097	1114	1109	1113	1108	1114	1101	1098	1115	1118	1108	1109	1108	1102	1099	1114	1121	1108	1107	1108	1098	1098	1107	1114	1112	1109	1103	1098	1103	1106	1104	1112	1113	1104	1104	1123	1113	1112	1117	1111	1107	1100	1116	1117
[success] Total time: 116 s, completed Jan 23, 2015 12:56:52 PM

ITERATOR MAP: s.stripMargin.lines.map(_.trim()).mkString(" ")

> run 100 10
[info] Running Foo 100 10
Foo$	1	1	1	0	0	1	1	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0	0	0	0	0	1	0	0	0	0	1	0
[success] Total time: 5 s, completed Jan 23, 2015 12:59:47 PM
> run 100 100
[info] Running Foo 100 100
Foo$	1	1	1	0	0	0	1	0	0	0	1	0	0	0	0	0	0	1	0	0	0	0	0	1	0	0	0	0	0	1	0	0	0	0	0	1	1	1	1	0	1	0	1	0	1	0	0	0	0	0	0	0	0	0	0	0	1	0	0	1	0	0	0	0	0	1	0	0	0	1	0	0	0	0	0	1	0	0	0	1	0	0	0	0	0	0	0	0	0	1	0	0	0	0	1	0	0	0	0	0
[success] Total time: 6 s, completed Jan 23, 2015 1:00:01 PM
> run 100 1000
[info] Running Foo 100 1000
Foo$	11	3	2	3	2	2	2	3	2	2	3	2	3	2	2	3	2	2	2	2	2	3	2	2	2	3	3	2	2	3	2	2	2	2	4	3	2	2	2	2	2	3	2	2	2	2	3	2	2	2	3	2	2	2	2	2	2	3	2	2	3	2	2	2	2	2	3	2	3	2	3	2	2	2	3	2	3	2	2	2	2	2	2	3	2	3	2	3	2	2	2	3	2	2	2	2	2	2	2	2
[success] Total time: 6 s, completed Jan 23, 2015 1:00:09 PM
> run 100 10000
[info] Running Foo 100 10000
Foo$	27	23	23	23	23	23	24	23	24	23	24	23	23	23	23	23	24	24	34	24	24	23	23	23	23	23	29	23	23	23	23	23	23	23	23	24	23	23	23	23	23	23	23	23	23	24	23	23	23	23	23	25	23	23	23	23	23	23	23	30	23	23	22	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	28	23	23	23	23	23	23	23	28	24	23	23	23	23	23	23
[success] Total time: 8 s, completed Jan 23, 2015 1:00:18 PM
> run 100 100000
[info] Running Foo 100 100000
Foo$	244	247	233	247	232	232	238	233	242	232	244	233	248	23	245	232	241	232	233	234	232	242	232	243	232	242	233	241	23	237	233	232	255	233	240	232	243	232	242	233	242	232	233	23	233	243	233	243	232	242	232	241	232	233	234	232	242	237	24	232	242	234	241	233	243	231	232	235	236	244	232	245	231	24	232	241	232	234	235	232	242	232	242	231	243	233	241	232	24	233	232	234	232	240	232	242	235	244	232	242
[success] Total time: 29 s, completed Jan 23, 2015 1:00:49 PM

SINGLE ITERATION WITH SUBSTRING TRIM:

  def collapseMargin(input: String): String = {
    input.lines.foldLeft(new StringBuilder(input.size)) { (buffer, line) =>
      val len = line.length

      var startIndex = 0
      var endIndex = len

      while (startIndex < len && line.charAt(startIndex) <= ' ') startIndex += 1
      while (endIndex > len && line.charAt(endIndex - 1) <= ' ') endIndex -= 1

      buffer append ' ' append line.substring(startIndex, endIndex)
    }.deleteCharAt(0).mkString
  }

> run 100 10
[info] Running Foo 100 10
Foo$	0	1	0	1	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0	0
[success] Total time: 5 s, completed Jan 23, 2015 12:50:01 PM
> run 100 100
[info] Running Foo 100 100
Foo$	1	1	0	0	1	1	0	0	0	1	1	0	0	0	1	0	0	1	1	0	0	0	0	1	1	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	0	0	1	0	0	1	0	0	1	0	1	0	1	0	0	1	0	0	0	0	0	0	1	0	0	0	1	0	0	0	0	1	0	0	1	1	0	0	1	0	1	1	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0
[success] Total time: 5 s, completed Jan 23, 2015 12:50:08 PM
> run 100 1000
[info] Running Foo 100 1000
Foo$	3	2	1	2	1	1	1	1	2	1	1	1	1	1	1	1	1	2	1	1	1	2	1	2	1	1	1	1	1	1	1	2	1	1	1	1	2	2	1	1	1	1	2	2	1	1	1	1	1	1	1	1	1	1	1	2	1	2	2	1	1	2	1	1	1	1	2	1	2	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	2	1	1	1	1	1	1	1	1	2
[success] Total time: 5 s, completed Jan 23, 2015 12:50:15 PM
> run 100 10000
[info] Running Foo 100 10000
Foo$	21	13	12	12	11	11	12	12	11	11	12	12	11	11	12	11	12	12	11	12	11	11	11	11	15	14	11	12	12	11	11	11	11	12	11	20	11	12	12	11	11	11	11	11	11	11	17	12	11	11	11	11	11	11	11	11	11	18	12	12	11	12	12	12	11	12	12	11	14	11	12	11	11	12	11	11	11	11	12	11	12	11	12	11	11	11	11	12	11	11	20	11	12	12	12	11	11	12	12	11
[success] Total time: 6 s, completed Jan 23, 2015 12:50:24 PM
> run 100 100000
[info] Running Foo 100 100000
Foo$	155	157	118	115	125	116	115	116	125	117	115	116	126	11	116	115	126	115	115	115	130	116	115	115	117	115	116	115	11	115	115	124	116	115	116	126	116	115	115	126	115	116	115	12	116	115	115	127	115	116	115	118	116	115	115	117	115	115	11	116	115	115	125	115	115	115	124	115	115	115	124	115	115	11	124	115	115	115	124	115	115	115	125	115	115	115	117	115	11	115	116	116	115	128	115	115	115	128	115	115
[success] Total time: 16 s, completed Jan 23, 2015 12:50:42 PM