Is Haskell self defined?

Question

For instance, how is function application defined (' ')? Does that definition have to be within the parser/compiler itself, or can it be overridden in a custom script?

Answer 1

Haskell is not defined metacircularly. It is defined by the haskell report: http://www.haskell.org/onlinereport/haskell2010/

There is no pluggable haskell compiler that lets you dynamically override application. You can use template haskell, or you can parse haskell using haskell-src-exts and write your own interpreter, or you can use plugins: http://www.haskell.org/ghc/docs/7.4.1/html/users_guide/compiler-plugins.html