One might experience an interesting compile error…
unexpected token: "" (column 1, code point U+200B)
…when compiling a phoenix project for iex.
The U+200B code, thank GOD it was there, can be looked up online, it means 0 width space. There are some platforms that allow one to copy this 0 width space.
After copying it, paste it into your ide’s “find” input field. I thought I only had one 0 width space, turns out I had eight. Deleted them all and the error was resolved.
edit: well actually that does a space with width. I remember on windows there were a funny (some key) + backspace that inserted a zero space width. Happened all the time too.
It probably could be fixed in similar way to Rust. It has big list of “similar” Unicode characters and will print message with name of the incorrect character next to the character that user probably wanted.
This probably would be a nice addition and maybe @josevalim can express his feelings about similar behaviour, as plain U+200B will not always tell users what can be wrong. More expressive errors in that case could be helpful in some situations.