Parsing the Logical expression

Sometimes you need to parse the logical expression.

I have made for my own purposes the regular expression which would distringuish all important tokens from the logical expression:
([\(!\s]*)[\s]*([^<=\s]+)[\s]*(<>|!=|==|<=|>=|<|>)[\s]*([^\s&|\)]*)[\s]*([\)]*)(&&|\|\|)?
or as java string:
"([\\(!\\s]*)[\\s]*([^<=\\s]+)[\\s]*(<>|!=|==|<=|>=|<|>)[\\s]*([^\\s&|\\)]*)[\\s]*([\\)]*)(&&|\\|\\|)?"

this would give for

 !(! (one== 56) && two>45) || !three!=funny
the following solution
Regular Expression ([\(!\s]*)[\s]*([^<=\s]+)[\s]*(<>|!=|==|<=|>=|<|>)[\s]*([^\s&|\)]*)[\s]*([\)]*)(&&|\|\|)?
as a Java string "([\\(!\\s]*)[\\s]*([^<=\\s]+)[\\s]*(<>|!=|==|<=|>=|<|>)[\\s]*([^\\s&|\\)]*)[\\s]*([\\)]*)(&&|\\|\\|)?"
Replacement $1fieldValue(\"$2\")$3$4$5$6
groupCount() 6
Test Target String matches() replaceFirst() replaceAll() lookingAt() find() group(0) group(1) group(2) group(3) group(4) group(5) group(6)
1 !(! (one== 56) && two>45) || !three!=funny No !(! (fieldValue("one")==56) && two>45) || !three!=funny !(! (fieldValue("one")==56) && fieldValue("two")>45) || !fieldValue("three")!=funny Yes Yes !(! (one== 56) !(! ( one == 56 ) null
next find() Yes two>45) two > 45 ) null
next find() Yes !three!=funny ! three != funny null

Comments

shree said…
Some people, when confronted with a problem, think "I know, I'll use regular expressions." Now they have two problems. -Jamie Zawinski
December 10, 2013 at 11:19 PM
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