Need to parse real numbers in a european locale, with comma separator

[tkau...@gmail.com]

Consider the decimal number, often represented with a  dot  as the decimal point.  (example   2.1 )

Then consider other locales, of which there are many, that use a comma to separate the decimal portion.  (example  2,1  in Germany)

When Jep parses  "2,1"  it regards the comma as a list separator and treats that as two numbers;  a   2  and a   1   .

I would think we would need to supply a different tokenizer so Jep won't treat the  2,1  as a list.  And then take some other action so the evaluator will accept the comma as marking the decimal place.

Is there any guidance on how to do this?

Thank you.

[Richard Morris]

This should be relatively straight forward using the Configurable Parser

http://www.singularsys.com/jep/doc/html/confparser.html

You basically needed to specify the regexp to match your desired form of number. "(\\d+\\,?\\d*)|(\\,\\d+)"

you will need a more complex one for numbers with exponents.

ConfigurableParser cp = new ConfigurableParser();
cp.addHashComments();
cp.addSlashComments();
cp.addDoubleQuoteStrings();
cp.addWhiteSpace();

//cp.addExponentNumbers();
cp.addTokenMatcher( 
   new NumberTokenMatcher("(\\d+\\,?\\d*)|(\\,\\d+)")  );
cp.addOperatorTokenMatcher();
cp.addSymbols("(",")","[","]",",");
cp.setImplicitMultiplicationSymbols("(","[");
cp.addIdentifiers();
cp.addSemiColonTerminator();
cp.addWhiteSpaceCommentFilter();
cp.addBracketMatcher("(",")");
cp.addFunctionMatcher("(",")",",");
cp.addListMatcher("[","]",",");
cp.addArrayAccessMatcher("[","]");

// Construct the Jep instance and set the parser
jep = new Jep();
jep.setComponent(cp);
 	

[Richard Morris]

After accepting numbers in the correct format you would also need to use some other symbol for the other places "," is normally used. Semi-colon is an obvious choice. Its used as a statement terminator, this is an optional feature which you may not need.

ConfigurableParser cp = new ConfigurableParser();
cp.addHashComments();
cp.addSlashComments();
cp.addDoubleQuoteStrings();
cp.addWhiteSpace();

//cp.addExponentNumbers();
cp.addTokenMatcher( new NumberTokenMatcher("(\\d+\\,?\\d*)|(\\,\\d+)") );

cp.addOperatorTokenMatcher();
cp.addSymbols("(",")","[","]",";"); // changed to use semi-colon
cp.setImplicitMultiplicationSymbols("(","[");
cp.addIdentifiers();
// cp.addSemiColonTerminator();  // need to comment this out
cp.addWhiteSpaceCommentFilter();
cp.addBracketMatcher("(",")");

cp.addFunctionMatcher("(",")",";"); // changed to use semi-colon
cp.addListMatcher("[","]",";"); // changed to use semi-colon

cp.addArrayAccessMatcher("[","]");

// Construct the Jep instance and set the parser
jep = new Jep();
jep.setComponent(cp);
 	

On Friday, 23 January 2015 19:01:22 UTC, tkau...@gmail.com wrote: