Xah Talk Show 2019-07-19 lisp syntax, s-exp, meta-expression, Mathematica, meaning of sugar syntax

topics covered:

• racket2 is planning a new syntax
• What is lisp? the characteristics of lisp.
• lisp syntax is actually not 100% regular.
• meaning of lisp “code is data”, aka Homoiconicity. This is actually ill defined. this term became popular around 2008. you see that lots of other languages not based on nested bracket, also qualify as Homoiconic. The heart of the lisp concept “code is data”, is actually regularity of nested syntax.
• example of 100% regular nested brackets syntax: Mathematica.
• the practical problems of purely nested syntax.
• emacs. why not use calc? because, using a real programing language (any python ruby JavaScript) in a full text editor is simpler, more flexble, more powerful.
• what is meta expression, aka mexp.
• the confusion of the concept “sugar syntax”, and the meaning of “syntactically equivalence”

Links:

• racket2 syntax proposal https://github.com/racket/racket/wiki/Racket2
• LISP Infix Syntax Survey
• Concepts and Confusions of Prefix, Infix, Postfix and Lisp Notations
• Fundamental Problems of Lisp
• What is Function, What is Operator?
• Sugar Syntax: Compiler Level vs User Level
• What is the Definition of Operator in Computer Language?
• Elisp: Lisp Symbol