Xah Talk Show 2019-08-04 emacs regex tutorial. ruby sigil, programing language type as syntax

topic covered:

• Emacs: Regex Tutorial
• example of regex use. M-x list-matching-lines. this command is a great way to test/learn regex in emacs.
• Regex are all similar. in perl python ruby php java JavaScript etc. But emacs regex is slightly more different.
• The main difference between emacs regex and other lang's regex.
• demo the power of regex. Find email addresses in a file. Find all emoji.
• The syntax of regex.

other topic mentioned:

• How Compiler Works
• Jargon Automata in Finite State Automata
• Predicate in Programing Languages and Naming
• Parameter names start with phi φ, variable names start with xi ξ
• The Sigils WAR, Language Design and Coding Convention
• Clojure: Variable Name Conventions