- Lisp only needs parentheses because its operators have variable arity, that’s about as deep as the “type system” goes.
- The concatenative languages wiki <https://concatenative.org> only lists Om <http://om-language.org> among the (non-reverse) Polish notation concatenative languages, but its semantics are a bit more tricky than those for RPN languages when expressed in terms of left-to-right evaluation (stream processing, not stacks).
- I think I’ve heard that the APL semantics is commonly described right to left so might be related?
- The proposed Lisp-2 notation with a syntactic distinction between operators and operands strongly reminds me of how the Self expression syntax <https://handbook.selflanguage.org/2017.1/langref.html#expres...> works (its main difference from Smalltalk).
- Lisp only needs parentheses because its operators have variable arity, that’s about as deep as the “type system” goes.
- The concatenative languages wiki <https://concatenative.org> only lists Om <http://om-language.org> among the (non-reverse) Polish notation concatenative languages, but its semantics are a bit more tricky than those for RPN languages when expressed in terms of left-to-right evaluation (stream processing, not stacks).
- Unrelated, but see XY <http://www.nsl.com/k/xy/xy.htm> for a very elegant RPN semantics.
- I think I’ve heard that the APL semantics is commonly described right to left so might be related?
- The proposed Lisp-2 notation with a syntactic distinction between operators and operands strongly reminds me of how the Self expression syntax <https://handbook.selflanguage.org/2017.1/langref.html#expres...> works (its main difference from Smalltalk).