codeworld-base-0.1.0.0: Replacement base module for CodeWorld

Safe HaskellNone

Prelude

Contents

Description

The standard set of functions and variables available to all programs.

You may use any of these functions and variables without defining them.

Synopsis

Documentation

Welome to CodeWorld! You can define your own pictures, animations, and games by defining variables and functions. There are four kinds of CodeWorld programs:

  • Pictures. To create a picture, you'll define the variable called main using pictureOf. The parameter to pictureOf should be a Picture. Example:
main = pictureOf(tree)
  • Animations. To create an animation, you'll define the variable called main using animationOf. The parameter to animationOf should be a function, mapping each time in seconds (a Number) to a Picture that is shown at that time. Example:
main = animationOf(spinningWheel)
  • Simulations. A simulation is like an animation, in that it changes over time. But while an animation changes in a simple regular way over time, a simulation can change in different ways depending on the state of things at any moment. To create a simulation, you should first decide on the type to describe the state of things (called the "world" type), and describe the simulation in terms of the starting state, the step that says how things change over time, and and a draw function that can build a picture from a state. Then you'll use simulationOf to define main. Example:
main = simulationOf(start, step, draw)
  • Interactions. Finally, you can build an interactive simulation, such as a game. This is very like a simulation, except that it also has an event function, which says how the state of things changes when events (like keys being pressed or the mouse moving) happen. You'll use interactionOf to define these. Example:
main = interactionOf(start, step, event, draw)

Numbers

data Number

The type for numbers.

Numbers can be positive or negative, whole or fractional. For example, 5, 3.2, and -10 are all values of the type Number.

Instances

Enum Number 
Eq Number 
Fractional Number 
Num Number 
Ord Number 
Show Number 

(+) :: Number -> Number -> Number infixl 6

Adds two numbers.

(-) :: Number -> Number -> Number infixl 6

Subtracts two numbers.

(*) :: Number -> Number -> Number infixl 7

Multiplies two numbers.

(/) :: Number -> Number -> Number infixl 7

Divides two numbers. The second number should not be zero.

(^) :: Number -> Number -> Number infixr 8

Raises a number to a power.

(>) :: Number -> Number -> Bool infix 4

Tells whether one number is greater than the other.

(>=) :: Number -> Number -> Bool infix 4

Tells whether one number is greater than or equal to the other.

(<) :: Number -> Number -> Bool infix 4

Tells whether one number is less than the other.

(<=) :: Number -> Number -> Bool infix 4

Tells whether one number is less than or equal to the other.

max :: (Number, Number) -> Number

Gives the larger of two numbers.

min :: (Number, Number) -> Number

Gives the smaller of two numbers.

negate :: Number -> Number

Gives the opposite (that is, the negative) of a number.

abs :: Number -> Number

Gives the absolute value of a number.

If the number if positive or zero, the absolute value is the same as the number. If the number is negative, the absolute value is the opposite of the number.

signum :: Number -> Number

Gives the sign of a number.

If the number is negative, the signum is -1. If it's positive, the signum is 1. If the number is 0, the signum is 0. In general, a number is equal to its absolute value (abs) times its sign (signum).

truncate :: Number -> Number

Gives the number without its fractional part.

For example, truncate(4.2) is 4, while truncate(-4.7) is -4.

round :: Number -> Number

Gives the number rounded to the nearest integer.

For example, round(4.2) is 4, while round(4.7) is 5.

ceiling :: Number -> Number

Gives the smallest integer that is greater than or equal to a number.

For example, ceiling(4) is 4, while ceiling(4.1) is 5. With negative numbers, ceiling(-3.5) is -3, since -3 is greater than -3.5.

floor :: Number -> Number

Gives the largest integer that is less than or equal to a number.

For example, floor(4) is 4, while floor(3.9) is 3. With negative numbers, floor(-3.5) is -4, since -4 is less than -3.5.

quotient :: (Number, Number) -> Number

Gives the integer part of the result when dividing two numbers.

For example, 3/2 is 1.5, but quotient(3, 2) is 1, which is the integer part.

remainder :: (Number, Number) -> Number

Gives the remainder when dividing two numbers.

For example, remainder(3,2) is 1, which is the remainder when dividing 3 by 2.

reciprocal :: Number -> Number

Gives the repicrocal of a number.

For example, reciprocal(5) is 1/5 (also written as 0.2).

pi :: Number

The constant pi, which is equal to the ration between the circumference and diameter of a circle.

pi is approximately 3.14159.

exp :: Number -> Number

Gives the exponential of a number. This is equal to the constant e, raised to the power of the number.

The exp function increases faster and faster very quickly. For example, if t is the current time in seconds, exp(t) will reach a million in about 14 seconds. It will reach a billion in around 21 seconds.

sqrt :: Number -> Number

Gives the square root of a number. This is the positive number that, when multiplied by itself, gives the original number back.

The sqrt always increases, but slows down. For example, if t is the current time, sqrt(t) will reach 5 in 25 seconds. But it will take 100 seconds to reach 10, and 225 seconds (almost 4 minutes) to reach 15.

log :: Number -> Number

Gives the natural log of a number. This is the opposite of the exp function.

Like sqrt, the log function always increases, but slows down. However, it slows down much sooner than the sqrt function. If t is the current time in seconds, it takes more than 2 minutes for log(t) to reach 5, and more than 6 hours to reach 10!

logBase :: (Number, Number) -> Number

Gives the logarithm of the first number, using the base of the second number.

sin :: Number -> Number

Gives the sine of an angle, where the angle is measured in degrees.

tan :: Number -> Number

Gives the tangent of an angle, where the angle is measured in degrees.

This is the slope of a line at that angle from horizontal.

cos :: Number -> Number

Gives the cosine of an angle, where the angle is measured in degrees.

asin :: Number -> Number

Gives the inverse sine of a value, in degrees.

This is the unique angle between -90 and 90 that has the input as its sine.

atan :: Number -> Number

Gives the inverse tangent of a value, in degrees.

This is the unique angle between -90 and 90 that has the input as its tangent.

atan2 :: (Number, Number) -> Number

Gives the angle between the positive x axis and a given point, in degrees.

acos :: Number -> Number

Gives the inverse cosine of a value, in degrees.

This is the unique angle between 0 and 180 that has the input as its cosine.

properFraction :: Number -> (Number, Number)

Separates a number into its whole and fractional parts.

For example, properFraction(1.2) is (1, 0.2).

even :: Number -> Bool

Tells if a number is even.

odd :: Number -> Bool

Tells if a number is odd.

gcd :: (Number, Number) -> Number

Gives the greatest common divisor of two numbers.

This is the largest number that divides each of the two parameters. Both parameters must be integers.

lcm :: (Number, Number) -> Number

Gives the least common multiple of two numbers.

This is the smallest number that is divisible by both of the two parameters. Both parameters must be integers.

sum :: [Number] -> Number

Gives the sum of a list of numbers.

product :: [Number] -> Number

Gives the product of a list of numbers.

maximum :: [Number] -> Number

Gives the largest number from a list.

minimum :: [Number] -> Number

Gives the smallest number from a list.

isInteger :: Number -> Bool

Tells whether a Number is an integer or not.

An integer is a whole number, such as 5, 0, or -10. Numbers with non-zero decimals, like 5.3, are not integers.

fromInteger :: Integer -> Number

fromRational :: Rational -> Number

fromInt :: Int -> Number

toInt :: Number -> Int

fromDouble :: Double -> Number

toDouble :: Number -> Double

Text

data Text :: *

Instances

Eq Text 
Data Text 
Ord Text 
Read Text 
Show Text 
IsString Text 
NFData Text 
Monoid Text 
Typeable * Text 

fromString :: String -> Text

append :: (Text, Text) -> Text

(<>) :: Text -> Text -> Text infixr 6

lines :: Text -> [Text]

words :: Text -> [Text]

unlines :: [Text] -> Text

unwords :: [Text] -> Text

join :: ([Text], Text) -> Text

replace :: (Text, Text, Text) -> Text

Replaces one piece of text with another.

For example, `replace("How do you do?", "do", "be")` is equal to `"How be you be?"`.

stripPrefix :: (Text, Text) -> Text

Removes a prefix from some text.

For example, `stripPrefix("Dr. Jones", "Dr. ")` is equal to `Jones`. If the prefix isn't there, the result is the same string, unchanged.

stripSuffix :: (Text, Text) -> Text

Removes a suffix from some text.

For example, `stripSuffix("smallest", "est")` is equal to `"small"`. If the suffix isn't there, the result is the same string, unchanged.

search :: (Text, Text) -> [Number]

Finds all indices where some text appears in a larger piece of text.

For example, `search("How do you do?", "do")` is equal to the list `[4, 11]`. Indices start at zero.

substring :: (Text, Number, Number) -> Text

Takes part of a string at a starting index and length.

For example, `substring("funny", 2, 2)` is equal to `"nn"`. Indices start at zero.

General purpose functions

data Bool :: *

Constructors

False 
True 

Instances

Bounded Bool 
Enum Bool 
Eq Bool 
Ord Bool 
Show Bool 
Random Bool 

(&&) :: Bool -> Bool -> Bool

(||) :: Bool -> Bool -> Bool

not :: Bool -> Bool

data Maybe a :: * -> *

Constructors

Nothing 
Just a 

Instances

Monad Maybe 
Functor Maybe 
MonadPlus Maybe 
Eq a => Eq (Maybe a) 
Ord a => Ord (Maybe a) 
Show a => Show (Maybe a) 

withDefault :: (Maybe a, a) -> a

Converts a Maybe value to a plain value, by using a default.

For example, `withDefault(Nothing, 5)` is equal to 5, while `withDefault(Just(3), 5)` is equal to 3.

maybe :: (Maybe a, a -> b, b) -> b

Gets a value from a Maybe value by applying either a default value or another function.

For example, `maybe(Nothing, blank, circle)` is a picture, while `maybe(Just(10), blank, circle)` is a picture of a circle with radius 10.

data Either a b :: * -> * -> *

Constructors

Left a 
Right b 

Instances

Monad (Either e) 
Functor (Either a) 
(Eq a, Eq b) => Eq (Either a b) 
(Ord a, Ord b) => Ord (Either a b) 
(Read a, Read b) => Read (Either a b) 
(Show a, Show b) => Show (Either a b) 
Typeable (* -> * -> *) Either 
type (==) (Either k k1) a b = EqEither k k1 a b 

either :: (Either a b, a -> c, b -> c) -> c

Gets a value from an Either value by applying either of two functions, depending on if the value is the left or right possibility.

For example, `either(Left(5), circle, text)` is a circle with radius 5. But `either(Right("hello"), circle, text)` is a picture with the text `"hello"`.

(==) :: a -> a -> Bool

(/=) :: a -> a -> Bool

fst :: (a, b) -> a

snd :: (a, b) -> b

toOperator :: ((a, b) -> c) -> a -> b -> c

Converts a function to an operator.

Example use:

f(x,y) = 2*x + y (%) = toOperator(f)

eight = 3 % 2

This has the same effect as defining % as:

x % y = 2*x + y eight = 3 % 2

fromOperator :: (a -> b -> c) -> (a, b) -> c

Converts an operator into a normal function.

Example use:

divide = fromOperator(/) four = divide(16, 4)

id :: a -> a

const :: a -> b -> a

(.) :: (b -> c) -> (a -> b) -> a -> c

flip :: ((a, b) -> c) -> (b, a) -> c

Converts a function into a version that takes the arguments in the opposite order.

Example:

f(x,y) = 2*x + y g = flip(f) eight = g(2,3)

until :: (a -> Bool, a -> a, a) -> a

Continues passing a value through a function until it meets a condition.

Example:

seven = until(odd, (/ 2), 56)

error :: Text -> a

ifThenElse :: Bool -> a -> a -> a

map :: ([a], a -> b) -> [b]

Applies a function to each element of a list, and produces a list of results.

For example, `map([1, 2, 3, 4, 5], circle)` is a list of circles of different sizes.

(++) :: [a] -> [a] -> [a]

filter :: ([a], a -> Bool) -> [a]

Keeps only the elements of a list for which a function evaluates to True.

For example, `filter([1, 2, 3, 4, 5], even)` is equal to `[2, 4]`.

first :: [a] -> a

rest :: [a] -> [a]

init :: [a] -> [a]

last :: [a] -> a

null :: [a] -> Bool

length :: [a] -> Number

(!!) :: [a] -> Number -> a

reverse :: [a] -> [a]

and :: [Bool] -> Bool

or :: [Bool] -> Bool

any :: ([a], a -> Bool) -> Bool

Determines if any member of a list matches a condition.

For example, `any([1, 2, 3], even)` is True, because 2 is even.

all :: ([a], a -> Bool) -> Bool

Determines if all members of a list match a condition.

For example, `all([2, 3, 4], even)` is False, because 3 is not even.

concat :: [[a]] -> [a]

concatMap :: ([a], a -> [b]) -> [b]

Builds a list from all of the members in the lists produced by applying a function to each element of the given list.

repeat :: a -> [a]

replicate :: (a, Number) -> [a]

cycle :: [a] -> [a]

take :: ([a], Number) -> [a]

drop :: ([a], Number) -> [a]

splitAt :: ([a], Number) -> ([a], [a])

takeWhile :: (a -> Bool) -> [a] -> [a]

dropWhile :: (a -> Bool) -> [a] -> [a]

span :: (a -> Bool) -> [a] -> ([a], [a])

break :: (a -> Bool) -> [a] -> ([a], [a])

isMember :: ([a], a) -> Bool

lookup :: ([(a, b)], a) -> Maybe b

transpose :: [[a]] -> [[a]]

subsequences :: [a] -> [[a]]

permutations :: [a] -> [[a]]

nub :: [a] -> [a]

sort :: [Number] -> [Number]

Colors

newtype Color

Constructors

RGBA (Number, Number, Number, Number) 

Instances

Show Color 

Pictures

type Point = (Number, Number)

type Vector = (Number, Number)

data Picture

Instances

Show Picture 

(&) :: Picture -> Picture -> Picture infixr 0

coordinatePlane :: Picture

A coordinate plane. Adding this to your pictures can help you measure distances more accurately.

Example:

main = pictureOf(myPicture & coordinatePlane) myPicture = ...

codeWorldLogo :: Picture

The CodeWorld logo.

Events

Entry points

data IO a :: * -> *

Instances

Monad IO 
Functor IO 

type Program = IO ()

simulationOf :: ([Number] -> a, (a, Number) -> a, a -> Picture) -> Program

interactionOf :: ([Number] -> a, (a, Number) -> a, (a, Event) -> a, a -> Picture) -> Program