yao2030

(load "stream-map.ss")
(load "ex59")

(define (scale-stream s f)
  (stream-map (lambda (x) (* x f)) s))
(define (mul-series s1 s2)
  (cons-stream (* (stream-car s1)
		  (stream-car s2))
	       (add-streams
		(scale-stream (stream-cdr s2) (stream-car  s1))

yao2030

def evaluatePoly(poly, x):
    result = 0.0
    for i in range(len(poly)):
        result += poly[i] * x ** i
    return result
# poly = [0.0, 0.0, 5.0, 9.3, 7.0]
# x = -13
# print evaluatePoly(poly, x)

def computeDeriv(poly):

yao2030

(define (and->if exp)
  (expand-and-clauses (and-clauses exp)))
(define (expand-and-clauses clauses)
  (if (null? clauses)
      true
      (let ((first (car clauses))
            (rest (cdr clauses)))
        (if (false? first)
            'f
            (make-if first (expand-and-clauses rest) false)))))

yao2030

(define (expand-clauses clauses)
  (if (null? clauses)
      'false                            ; no else clause
      (let ((first (car clauses))
            (rest (cdr clauses)))
       (if (cond-else-clause? first)
            (if (null? rest)
                (sequence->exp (cond-actions first))
                (error "ELSE clause isn't last -- COND->IF"
                       clauese))

yao2030

(define (let? exp)
  (tagged-list? exp 'let))

(define (let-clauses exp)
  (cdr exp))

(define (get-parameters clauses)
  (if (null? (car clauses))
      '()
      (cons (caaar clauses)

yao2030

(define (let*->nested-lets clauses)
  (if (null? (car clauses))
      (cadr clauses)
      (list 'let (list (caar clauses))
            (let*->nested-lets (cons (cdar clauses)
                                     (cdr clauses))))))


1 ]=> (let*->nested-lets '(((x 3) (y (+ x 2)) (z (+ x y 5))) (* x z)))

yao2030

# def fib(n):
#     global numCalls
#     numCalls += 1
#     print 'fib called with', n
#     if n == 0 or n == 1:
#         return 1
#     else:
#         return fib(n-1) + fib(n-2)

# # numCalls = 0

yao2030

#!/usr/bin/perl
use strict;

print "Looking for my files that are both writable and executable\n";

die "No file specified\n" unless @ARGV;

my @myfile;

foreach my $file (@ARGV)

yao2030

#/usr/bin/perl
##Copyright (C) 2013 by Yours truly
#
$_ = "I saw Barney\ndown at the bowling alley\nwith Fred\nlast night.\n";

if (m{
        barney # the little guy
        .* # anthing in between
        fred # the loud guy
    }six)

yao2030

#/usr/bin/perl
##Copyright (C) 2013 by Yours truly

$_ = "Hello there, neighbor";

if (/(\S+) (\S+), (\S+)/) 
{
    print "words were $1 $2 $3\n";
}