August 26

Teams

Pattern Matching and Structural Recursion

Examples:

• L_Int_height.rkt

• L_Int_height.py

Definitional Interpreters for L_Int

interp-Rint.rkt

Rint-interp-example.rkt

interp_Pint.py

The L_Var Language: L_Int + variables and let

Racket version:

exp ::= int | (read) | (- exp) | (+ exp exp) 
      | var | (let ([var exp]) exp)
L_Var ::= exp

Python version:

exp ::= int | input_int() | - exp | exp + exp | var
stmt ::= print(exp) | exp | var = exp
L_Var ::= stmt*

Racket examples:

(let ([x (+ 12 20)])
  (+ 10 x))

(let ([x 32]) 
  (+ (let ([x 10]) x) 
     x))

Python examples:

x = 12 + 20
print(10 + x)

x = 33
x = 10
print(x + x)

Racket Interpreter for L_Var: interp-Rvar.rkt

Python Interpreter for L_Var: interp_Pvar.rkt

x86 Assembly Language

reg ::= rsp | rbp | rsi | rdi | rax | .. | rdx  | r8 | ... | r15
arg ::=  $int | %reg | int(%reg) 
instr ::= addq  arg, arg |
		  subq  arg, arg |
		  negq  arg | 
		  movq  arg, arg | 
		  callq label |
		  pushq arg | 
		  popq arg | 
		  retq 
prog ::=  .globl main
		   main:  instr^{+}

Intel Machine: * program counter * registers * memory (stack and heap)