What language are you referring to? I'm not quite sure I understand your examples. -------- Related: In Haskell, any 2-argument function can be used (or def

What language are you referring to? I'm not quite sure I understand your examples. -------- Related: In Haskell, any 2-argument function can be used (or defined) infix by surrounding it with backticks, eg: add 2 3 is equivalent to: 2 `add` 3 ---- And you can use this to cleanly write curried functions (often predicates) with their arguments flipped, eg: vowelCount = length . filter (`elem` "aeiou") ---- Note that functions named with punctuation characters are infix by default, and one can be used/defined prefix by surrounding it with brackets, eg: (<$>) = fmap toUpper <$> "aeiou" # => "AEIOU" ---- It's also convenient for resolving a subset of one of the harder problems in computer science: naming things. For a 2-argument function, use it infix and read it as a phrase in english. Which is clearer: ".jpg" `isSuffix` url or: ".jpg" `isSuffixOf` url You can also define functions' precedence and associativity (left/right) when used as an infix operator.