ShuntingYardConverter silently drops tokens

[Maxr1998]

ShuntingYardConverter silently drops tokens

[uklimaschewski]

I plan a release after some more issues are fixed, will be soon.

[HSGamer]

After debugging some nonsense & evaluable strings, I think the culprit is in this line

EvalEx/src/main/java/com/ezylang/evalex/parser/ShuntingYardConverter.java

Line 115 in 9c78907

return operandStack.pop();

When I try the normal expressions, the operandStack size is mostly 1 so it'll take the whole tokenized node.
However, when I try the nonsense strings, the operandStack size is higher than 1 (Test 2 + 2 2 + 3 would be 3) and the line would take the last node in the stack.

I think we should include another exception check when operandStack is higher than 1 after the Shunting Yard conversion.

EDIT: Is there any legit case where the operandStack size is higher than 1? Because I could be wrong since I only tested with a little part of the Unit Tests.

[HSGamer]

When looking at it quickly back then, I also noticed this. There may be some use case if you use functions with multiple parameters. You could try how it behaves for an if call for example.

It's verified that the size is also 1 (IF(5 + 2 > 3, 5 + 2, 2 + 3) + FLOOR(11.2)).
I'll make a PR and wait for the owner to reply further more.

[RobertZenz]

I believe that is implicit multiplication at work.

Test 2 + 2 2 + 3
   0 2 + 2 2 + 3
   0*2 + 2*2 + 3
   0   +  4  + 3 = 7

Basically, but seems like the first one is dropped somewhen before the actual evaluation because the variable is not set.

[Maxr1998]

I don't think that's the case. An unset variable should error out, but it doesn't because it's already dropped before the abstract syntax tree is evaluated.

Another example: 2 3 + 4 evaluates to 7, which completely ignores the 2. If it was implicit multiplication, it should result in 9.

[RobertZenz]

That's true, then I'm out of ideas.

[HSGamer]

Test World would become {"type":"VARIABLE_OR_CONSTANT","value":"World"}
Test World Hello would become {"type":"VARIABLE_OR_CONSTANT","value":"Hello"}
Test World 1 would become {"type":"NUMBER_LITERAL","value":"1"}

So, same issue I guess.

[Maxr1998]

When looking at it quickly back then, I also noticed this. There may be some use case if you use functions with multiple parameters. You could try how it behaves for an if call for example.

[Maxr1998]

Thanks for the fix and merge! Will there be a patch release with this fix applied in the near future?

[Maxr1998]

Alright, no rush, thanks for the info though!