Error with If Statment in Liberty/ISE Eiffel - utf-8

Question

I have a problem with the if statment.
I have a program with commandline-arguments and utf8 (€ - Symbol).
The error is in works_not in the if statement.
class EURO
insert ARGUMENTS
create {ANY}
make
feature {ANY}
make
do
works_not
works
end
works_not
local ok: BOOLEAN
do
print ("%N%NAnzahl Argumente : " + argument_count.to_string + "%N")
print ("%NArgument -> Programmname : " + argument(0))
print ("%NArgument -> Wert : " + argument(1))
print ("%NArgument -> Währung : " + argument(2) + "%N")
ok := argument(2) = "€"
print ("%NArgument(2) ist Euro ? " + ok.to_string + "%N%N")
print ("don't work")
io.put_new_line
if argument(2) = "€" then
euro_in_dm(argument(1).to_real)
else
dm_in_euro(argument(1).to_real)
end
end
works
do
print ("works ")
io.put_new_line
if argument_count /= 2 then
print("%N%N Error (1) %N%N")
else
inspect
argument(2)
when "€" then
euro_in_dm(argument(1).to_real)
when "DM","dm" then
dm_in_euro(argument(1).to_real)
else
print("%N%N Error (2) %N%N")
end
end
end
feature
euro_in_dm (a: REAL)
do
io.put_string("%N Euro -> DM ")
io.put_real(a * 1.95583)
io.put_string("%N%N")
end
dm_in_euro (a: REAL)
do
io.put_string("%N DM -> Euro ")
io.put_real(a / 1.95583)
io.put_string("%N%N")
end
end

Answer 1

The issue is in the comparison operator argument(2) = "€".
In Eiffel strings have a reference type, so the equality operator = compares references to the string objects, not their contents. If you want to compare the string values instead, you need to use an operator ~ that internally calls is_equal after checking that types of both operands are exactly the same, or a more robust version same_string (provided that it is available in your version of the environment). To summarize, you can try one of the following instead of the equality:
argument(2).same_string ("€")
argument(2) ~ "€"
argument(2).is_equal ("€")