Itty Bitty Programming Language Assignment

Credit

This assignment is based on MUPL by Dan Grossman and his team at UW.

Code To Investigate

Ast

(struct IdentifierExp (name)                                           #:transparent)
(struct IntExp        (value)                                          #:transparent)
(struct AddExp        (left_exp right_exp)                             #:transparent)
(struct IfGreaterExp  (left_exp right_exp then_body_exp else_body_exp) #:transparent)
(struct NilExp        ()                                               #:transparent)
(struct IsNilExp      (exp)                                            #:transparent)
(struct ConsExp       (car_exp cdr_exp)                                #:transparent)
(struct CarOfConsExp  (cons_exp)                                       #:transparent)
(struct CdrOfConsExp  (cons_exp)                                       #:transparent)
(struct LetExp        (binding_name binding_exp body_exp)              #:transparent)
(struct FunctionExp   (name_option parameter_name body_exp)            #:transparent)
(struct CallExp       (function_exp argument_exp)                      #:transparent)

Code To Implement

Eval

lookup-value-in-environment

(struct entry (name value) #:transparent)

(define (lookup-value-in-environment env identifier-name)
  (cond [(null? env) (error "unbound identifier during evaluation" identifier-name)]
        [(equal? (entry-name (car env)) identifier-name) (entry-value (car env))]
        [#t (lookup-value-in-environment (cdr env) identifier-name)]))

Macros

IbLet*

(struct binding (name exp) #:transparent)