Class: StringUtilities

• Inheritance
• Description
• Class protocol
  • edit distance

Inheritance:

   Object
   |
   +--StringUtilities

Package:

stx:libbasic2

Category:

Collections-Text-Support

Version:

rev: 1.1 date: 2009/08/16 21:07:08

user: cg

file: StringUtilities.st directory: libbasic2

module: stx stc-classLibrary: libbasic2

Description:

some less often used algorithms have been moved to here to
make libbasic more compact.

Class protocol:

 editDistanceFrom: s1 to: s2 s: substWeight k: kbdTypoWeight c: caseWeight e: exchangeWeight i: insrtWeight

 isKey: k1 nextTo: k2

return true, if k1 and k2 are adjacent keys on the keyboard.
This is used to specially priorize plausible typing errors of adjacent keys.

 isKey: k1 nextTo: k2 onKeyboard: keys

return true, if k1 and k2 are adjacent keys on the keyboard defined by keys

 keyboardLayout

the keyboard layout (used with algorithms to find possible typing errors,
for example: edit distance in levenshtein)

 keyboardLayoutForLanguage: lang

the keyboard layout (used with algorithms to find possible typing errors,
for example: edit distance in levenshtein).
CAVEAT: hard coded us- and german keyboards here.

 levenshteinDistanceFrom: string1 to: string2 s: substWeight k: kbdTypoWeight c: caseWeight e: exchangeWeight i: insrtWeight d: deleteWeight

parametrized levenshtein.
return the levenshtein distance of two strings;
this value corrensponds to the number of replacements that have to be
made to get string2 from string1.

The arguments are the costs for
s:substitution,
k:keyboard type (substitution), if nil, s is used
c:case-change, if nil, s is used
i:insertion
d:deletion
e:exchange if nil, s*2 is used
of a character.
See IEEE transactions on Computers 1976 Pg 172 ff.