Groovy numeric String compare

Question

What do I do wrong:

assert  'foo'  == 'foo'  //PASS
assert  '500'  == '500'  //PASS
assert  '500'  <  '1000' //FAIL <-- Supposed to pass
assert  '500'  <= '1000' //FAIL <-- Supposed to pass
assert  '1000' >  '500'  //FAIL <-- Supposed to pass
assert  '1000' >= '500'  //FAIL <-- Supposed to pass

It is for a customizable "condition" object:

class Condition {
    static def compareClosure = [
            '==' : { a, b -> a == b},
            '!=' : { a, b -> a != b},
            '<'  : { a, b -> a <  b},
            '<=' : { a, b -> a <= b},
            '>'  : { a, b -> a >  b},
            '>=' : { a, b -> a >= b}
    ]

    String comparator
    def value

    Condition(String comparator, String value) {
        this.value = value
        this.comparator = comparator
    }

    boolean isSatisfiedBy(def value) {
        compareClosure[comparator](value, this.value)
    }
}

So

assert new Condition('<=', '1000').isSatisfiedBy('500') //FAIL

Is there a way to do this without converting value to a numeric type ?

http://stackoverflow.com/questions/1262239/natural-sort-order-string-comparison-in-java-is-one-built-in — tim_yates, Mar 21 '13 at 22:52

James Kleeh · Answer 1 · 2013-03-22T02:13:30.490

0

The short answer to your question is no.

However, I have a feeling this is for sorting purposes. If that is the case. Here is the sort function I use for this purpose.

Example in action: Groovy Web Console

    Closure customSort = { String a, String b ->
      def c = a.isBigDecimal() ? new BigDecimal(a) : a
      def d = b.isBigDecimal() ? new BigDecimal(b) : b


      if (c.class == d.class) {
        return c <=> d
      } else if (c instanceof BigDecimal) {
        return -1
      } else {
        return 1
      }

    }

['foo','500','1000', '999', 'abc'].sort(customSort)

edited Mar 22 '13 at 02:13

answered Mar 21 '13 at 22:36

James Kleeh

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Thanks, it was not for that purpose. I've edited my question with more info – Thermech Mar 21 '13 at 23:24
Instead of relying on exceptions, use [String.isInteger()](http://groovy.codehaus.org/groovy-jdk/java/lang/String.html#isInteger%28%29): `c = a.integer ? a.toInteger() : a` – OverZealous Mar 22 '13 at 00:27
Thanks - didn't know that was out there – James Kleeh Mar 22 '13 at 02:11

Groovy numeric String compare

1 Answers1