Homogenous prefix notation is a reliable behavior and constraint of Lisp’s syntax, but is probably also one of the things that trips up most people when they are trying to read and make sense of long programs. Infix notation is a very natural form for defining collaboration between terms, whether it’s 1 + 1 or Alice and Bob.

I admit, my opinion of infix may possibly cultural-linguisitically biased as grammar in other languages could have adopted prefix action words before subject and object). Mechanistically however, infix operators have the advantage of not requiring an expression delimiter-set like ( ... ) to indicate expression completeness too.

In Ruby, the infix operators like +, * and << are all modeled as methods sent to the left operand with the right operand as argument. In practise this tends to work out okay most of the time, but without something like refine, it is not possible to define operators for use with DSLs unless you also define special objects for those DSLs, which can make embedding the DSL more cumbersome.

Having worked a lot with Cucumber in the past 2 years to define acceptance tests/executable features, I’ve grown accustomed to and am enjoying the flexibility in begin able to define a library of functions (Step Definitions) with somewhat arbitrary “anyfix” composition properties.

There are technical reasons why this is not easily applicable to typical general imperative programming language design, but apart from the typical “you’ll shoot your eye out” caveat, there are no essential concept violations by providing an “anyfix” expression signature capability for general programming.

Imagine for example a function definition such as:

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function shoot(shooter, target, weapon) {
  ...
}

shoot(cowboy, alien, pistol);

…could instead be mapped as…

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function (shooter) shoot at (target) with (weapon) {
  ...
}

(cowboy) shoot at (alien) with (pistol);
// or possibly sans-parentheses as...
cowboy shoot at alien with pistol;

A language with a feature like that could lead to some pretty sweet embedded DSLs. Just sayin’.