Week 01: Introduction & the Cool Programming Language

How to Run the Program

• Compiler (Offline)
  • $Program \rightarrow Compiler \rightarrow Execute$
  • $Data \rightarrow Execute \rightarrow Output$
• Interpreter (Online)
  • $Program + Data \rightarrow Interpreter \rightarrow Output$

Compiler Concept

• (Syntactic) Lexical Analysis
  • Concept: Divide program text into words or tokens.
  • Input: text
  • Output: words or tokens
  • Sample Input: if x == y then z = 1; else z = 2;
  • Sample Output: #IF #ID(x) #EQAUL #ID(y) #THEN ...
• (Syntactic) Parsing
  • Concept: Diagramming Sentences.
  • Input: Tokens
  • Output: Abstruct Semantic Tree
  • Sample Input: #INT(5) #PLUS #INT(3) #MULTIPLY #INT(5)
  • Sample Output: (#PLUS (#INT(5)) (#MULTIPLY (#INT(3)) (#INT(5))))
• (Types scope) Semantic Analysis
  • Concept: Catch inconsistencies.
  • Sample Input: { int Jack=3; { int Jack=4; cout << Jack; } }
  • Question: What is the value?
• Optimization
  • Concept: Run faster/Use less memory/Use low power/network.
• (Translation) Code Generation
  • Concept: Produce assembly code.

Related Questions

• Why are there so many programming languages?
  • Application domains have distinct/conflicting needs.
• Why are there new programming languages?
  • Programming training is the dominant cost for a programming language.
  • Wild-used languages are slow to change.
  • Easy to start a new language: when productivity > training cost
  • Languages adopted to fill a void. (Void means new techniques.)
• What is a good programming languages?
  • There is no universally accepted metric for language design.