kmicinski

#lang racket

;; tail recursive functions
(define (filter f l)
  (define (h l acc)
    (match l
      ['() acc]
      [`(,hd . ,tl)
       (if (f hd)
           (h tl (cons hd acc))

kmicinski

#lang racket

(define x '(this (is an) s expression))

;; Write a function that takes an input list l
;; and adds 2 to every element of the list
;; assume all elements are numbers
#;(define (add-two-to-each l)
  (define addtwo (lambda (x) (+ x 2)))
  ;(define (addtwo x) (+ x 2))

kmicinski

#lang racket

;; Thursday, Dec 8, 2022
;; Class 2 -- Type Inference
;; 
;; In this exercise, we will study type inference, and
;; a variety of type system features.

(provide (all-defined-out))

kmicinski

#lang racket

;; Assignment 4: A church-compiler for Scheme, to Lambda-calculus

(provide church-compile
         ; provided conversions:
         church->nat
         church->bool
         church->listof)

kmicinski

#lang racket

;; Midterm 2 -- Practice Solution

(foldr + 5 '(1 2 3))
;; call the lambda f
;; call the initial value i

(+ 1 (+ 2 (+ 3 5)))

kmicinski

#lang racket

;; How to handle let and let*
(let* ([x 1]
       [y x])
  ((lambda (z) z) y))

(define (prim? s) (member s '(+ - * = equal? list cons car cdr null?)))
(define prim->op (hash '+ + '- - '* * '= = 'equal? equal? 'list list 'cons cons
                       'car car 'cdr cdr 'null? null?))

kmicinski

;; Closure-Creating Interpreters in Racket
#lang racket

;; expressions comprise the λ-calculus extended
;; to include numeric constants and the + builtin
(define (expr? e)
  (match e
    [(? number? n) #t]
    [`(+ ,(? expr? e0) ,(? expr? e1)) #t]
    [(? symbol? x) #t]

kmicinski

#lang racket

;; λ Calculus Exercises
;; Tue, Oct 25, 2022
;; CIS 352

;; Exercise 1:
;; ((λ (x) x) (λ (y) y))
;; Perform beta reduction on this term
;; For credit: the substitution must be made explicit

kmicinski

#lang racket

;; λ Calculus Exercises
;; Tue, Oct 25, 2022
;; CIS 352

;; Exercise 1:
;; ((λ (x) x) (λ (y) y))
;; Perform beta reduction on this term
;; For credit: the substitution must be made explicit

kmicinski

#lang racket
(provide (all-defined-out))

;;
;; CIS352 (Fall '22) -- IfArith Intro
;;

;; builtin functions
(define (function-name? fn)
  (member fn '(+ - / * mod == =0? not)))