#lang planet wrturtle/pyret/bsl

# Exercises in chapter 2 of HtDP, written in pyret/bsl

# Exercise 1
def x: 8
def y: 36

# Create an expression that computes the distance between x and y
sqrt(x * x + y * y)

# Exercise 2
def prefix: "hello"
def suffix: "world"

# Create an expression that adds "_" between prefix and suffix

prefix + "_" + suffix

# Exercise 3
def str: "helloworld"
def i: 5

# Create an expression that adds "_" at the ith position of str
substring(str, 0, i) + "_" + substring(str, i, len(str))

# Exercise 4
# Same setup as ex 3, but this time, /remove/ the letter at position i
substring(str, 0, i) + substring(str, i+1, len(str))

# See `chapter2-images.rkt` for the exercises involving images.

# Exercise 9
def b1: True
def b2: False

# Create an expression tfhat determines whether b1 is False or b2 is True
b1 = False or b2 = True