LangStudies/App/EoI/Lectures/Lecture.1.2.3.Notes.md

Pipeline

Interpretation Involves RUNTIME SEMANTICS

THE MEANING OF THE PROGRAM MODEL

Compliation delegates semantics of runtime behavior to a TARGET language

Interpetation deals with the semantics itself.

Types of Interpreter implementation:

• AST-based (recursive)
• Bytecode (Virtual Machines)

Types of Compiler implementation:

• Ahead-of-time (AOT)
• Just-in-time (JIT)

Interpeter-AST:

Translation Stage:

1. Program Model
2. Lexer: Processing into token elements for a parser.
   • Output : Tokens
3. Parser: Syntactic Analysis
   • Output : Abstract Syntax Tree (AST)

Runtime Stage: 4. Interpeter 5. Runtime Behavior

Interpreter-Bytecode:

Translation Stage:

1. Program Model
2. Lexer: Processing into token elements for a parser.
   • Output : Tokens
3. Parser: Syntactic Analysis
   • Output : Abstract Syntax Tree (AST)
4. Bytecode Emitter
5. Bytecode instructions primed.

Runtime Stage: 6. Interpreter 7. Runtime Behavior

Types of Virtual Machine behavior:

• Stack based
  • Stack for operands and operators
  • Result is always on top of stack
• Register based
  • Virtual registers
  • Result in accumulation register
  • Map to real via register allocation

Compiler Ahead-of-Time:

1. Program Model
2. Lexer: Processing into token elements for a parser.
   • Output : Tokens
3. Parser: Syntactic Analysis
   • Output : Abstract Syntax Tree (AST)
4. Code Generator
5. Intermediate representation primed
6. Target machine instruction set code generation
7. Target machine is intended interpretation platform.
8. Runtime Behavior.

Compiler with LLVM platform:

1. Program Model
2. Lexer: Processing into token elements for a parser.
   • Output : Tokens
3. Parser: Syntactic Analysis
   • Output : Abstract Syntax Tree (AST)
4. LLVM IR generator
5. LLVM Native code generator
6. Target machine is intended interpretation platform
7. Runtime Behavior.

Lexer, and parser are considered FRONT-END.
Code Generation or byte-code gen or interpreter ast impelementation gen for target instruction platform is considered BACK-END.

Jit Compiler:

1. Program Model
2. Lexer: Processing into token elements for a parser.
   • Output : Tokens
3. Parser: Syntactic Analysis
   • Output : Abstract Syntax Tree (AST)
4. Bytecode Emitter
5. Bytecode fed to interpeter
6. Interetor may code gen immediately to target hardware platform or interpret ast directly.
7. Runtime Behavior.

Transpiler:

1. Program Model in input langauge
2. Lexer: Processing into token elements for a parser.
   • Output : Tokens
3. Parser: Syntactic Analysis
   • Output : Abstract Syntax Tree (AST)
4. AST Transformation to target AST
5. Code generation
6. Program Model in output langauge