Example 3: W4


From UAX#9:
W4. A single European separator between two European numbers changes to a European number. A single common separator between two numbers of the same type changes to that type:
Actual code:
'continue' while s/$EN$ES$EN/$EN$EN$EN/g;

'continue' while s/([$EN$AN])$CS\1/$1$1$1/g;

Details: