codeworld-base-0.2.0.0: Replacement base module for CodeWorld

Safe HaskellNone
LanguageHaskell98

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 
Floating Number 
Fractional Number 
Num Number 
Ord Number 
Real Number 
RealFloat Number 
RealFrac 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 -> Truth infix 4

Tells whether one number is greater than the other.

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

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

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

Tells whether one number is less than the other.

(<=) :: Number -> Number -> Truth 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.

opposite :: 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).

truncation :: Number -> Number

Gives the number without its fractional part.

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

rounded :: 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 -> Truth

Tells if a number is even.

odd :: Number -> Truth

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 -> Truth

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 

fromString :: String -> Text

toString :: Text -> String

fromCWText :: Text -> Text

toCWText :: Text -> Text

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

lines :: Text -> [Text]

unlines :: [Text] -> Text

words :: Text -> [Text]

unwords :: [Text] -> Text

joined :: [Text] -> Text

substitution :: (Text, Text, Text) -> Text

Gives the result of replacing one piece of text with another.

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

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

Gives the result of performing many substitutions in a piece of text. This is commonly used to build text to show in a program, as in this example:

substitutions("Lives: [lives] of 3 Score: [score]", [("[lives]", printed(lives)), ("[score]", printed(score))])

General purpose functions

ifThenElse :: Truth -> a -> a -> a

(==) :: a -> a -> Truth infix 4

Compares values to see if they are equal.

(/=) :: a -> a -> Truth infix 4

Compares values to see if they are not equal. Note that `a /= b` is the same as `not (a == b)`.

type Truth = Bool

data Bool :: *

Constructors

False 
True 

Instances

Bounded Bool 
Enum Bool 
Eq Bool 
Ord Bool 
Show Bool 
Ix Bool 
Generic Bool 
Bits Bool 
FiniteBits Bool 
Random Bool 
Unbox Bool 
MVector MVector Bool 
Vector Vector Bool 
type Rep Bool = D1 D1Bool ((:+:) (C1 C1_0Bool U1) (C1 C1_1Bool U1)) 
data Vector Bool = V_Bool (Vector Word8) 
data MVector s Bool = MV_Bool (MVector s Word8) 
type (==) Bool a b = EqBool a b 

(&&) :: Truth -> Truth -> Truth infixr 3

(||) :: Truth -> Truth -> Truth infixr 2

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

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

firstOfPair :: (a, b) -> a

Returns the first element of an ordered pair.

secondOfPair :: (a, b) -> b

Returns the second element of an ordered pair.

error :: Text -> a

Fails with an error message.

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

empty :: [a] -> Truth

Determines whether a list is empty or not.

contains :: ([a], a) -> Truth

Determines whether a value is a member of a list or not.

length :: [a] -> Number

Gives the length of a list.

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

Gives the member of a list at a given index. Indices start at 0.

(#) :: [a] -> Number -> a infixl 9

Gives the member of a list at a given index. Indices start at 0.

any :: [Truth] -> Truth

Determines if any proposition in a list is true.

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

all :: [Truth] -> Truth

Determines if all propositions in a list are true.

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

none :: [Truth] -> Truth

Determines if all propositions in a list are false.

For example, `none([odd(n) | n <- [2,3,4]])` is False, because 3 is odd.

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

Forms a list by repeating a source list some number of times.

repeating :: [a] -> [a]

Forms a list by repeating a source list forever.

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

Gives the first members of a list, up to the given number.

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

Gives the last members of a list, up to the given number.

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

Gives all members of a list after the given number.

In general, `xs = first(xs, n) ++ rest(xs, n)`.

while :: ([a], a -> Truth) -> [a]

Gives the longest prefix of a list for which a condition is true.

For example, `while([2,4,5,6], even) = [2,4]`.

until :: ([a], a -> Truth) -> [a]

Gives the longest prefix of a list for which a condition is false.

For example, `until([2,4,5,6], odd) = [2,4]`.

after :: ([a], a -> Truth) -> [a]

Gives the remaining portion of a list after the longest prefix for which a condition is true.

In general, `xs = while(xs, cond) ++ after(xs, cond)

concatenation :: [[a]] -> [a]

Gives the concatenation of all of the lists in its input.

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

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

sorted :: [Number] -> [Number]

Gives a list of numbers reordered into increasing order.

reversed :: [a] -> [a]

Gives a list in the opposite order of the original.

unique :: [a] -> [a]

Gives a list with all duplicate members removed.

transposed :: [[a]] -> [[a]]

combined :: ((a, a) -> a, [a]) -> a

Combines a list of values into a single value, by merging members with a function. The function should take two parameters, and should be associative (so `f(x,f(y,z)) = f(f(x,y),z)`). The list should be non-empty.

For example, `combined(fromOperator(+), [1, 3, 5])` is equal to `9`.

data Maybe a :: * -> *

Constructors

Nothing 
Just a 

Instances

Monad Maybe 
Functor Maybe 
Applicative Maybe 
Foldable Maybe 
Generic1 Maybe 
Alternative Maybe 
MonadPlus Maybe 
Show1 Maybe 
Read1 Maybe 
Ord1 Maybe 
Eq1 Maybe 
Eq a => Eq (Maybe a) 
Ord a => Ord (Maybe a) 
Show a => Show (Maybe a) 
Generic (Maybe a) 
Monoid a => Monoid (Maybe a) 
(Selector s, ToJSON a) => RecordToPairs (S1 s (K1 i (Maybe a))) 
(Selector s, FromJSON a) => FromRecord (S1 s (K1 i (Maybe a))) 
type Rep1 Maybe = D1 D1Maybe ((:+:) (C1 C1_0Maybe U1) (C1 C1_1Maybe (S1 NoSelector Par1))) 
type Rep (Maybe a) = D1 D1Maybe ((:+:) (C1 C1_0Maybe U1) (C1 C1_1Maybe (S1 NoSelector (Rec0 a)))) 
type (==) (Maybe k) a b = EqMaybe k a b 

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.

hasValue :: Maybe a -> Truth

Determines if a Maybe has a value.

definitely :: Maybe a -> a

Extracts the value from a Maybe, and crashes the program if there is no such value.

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

data IO a :: * -> *

Instances

Monad IO 
Functor IO 
Applicative IO 
PrimMonad IO 
PrimBase IO 
type PrimState IO = RealWorld 

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 
Floating Number 
Fractional Number 
Num Number 
Ord Number 
Real Number 
RealFloat Number 
RealFrac Number 
Show Number 

data Text

Instances

Eq Text 

Colors

newtype Color

Constructors

RGBA (Number, Number, Number, Number) 

Instances

Eq Color 

type Colour = Color

Pictures

type Point = (Number, Number)

type Vector = (Number, Number)

data Picture

data TextStyle

Constructors

Plain 
Italic 
Bold 

blank :: Picture

A blank picture

path :: [Point] -> Picture

A thin sequence of line segments with these endpoints

thickPath :: ([Point], Number) -> Picture

A thin sequence of line segments, with these endpoints and line width

polygon :: [Point] -> Picture

A thin polygon with these points as vertices

thickPolygon :: ([Point], Number) -> Picture

A thin polygon with these points as vertices

solidPolygon :: [Point] -> Picture

A solid polygon with these points as vertices

curve :: [Point] -> Picture

A thin curve passing through these points.

thickCurve :: ([Point], Number) -> Picture

A thick curve passing through these points, with this line width

loop :: [Point] -> Picture

A thin closed loop passing through these points.

thickLoop :: ([Point], Number) -> Picture

A thick closed loop passing through these points, with this line width.

solidLoop :: [Point] -> Picture

A solid closed loop passing through these points.

rectangle :: (Number, Number) -> Picture

A thin rectangle, with this width and height

solidRectangle :: (Number, Number) -> Picture

A solid rectangle, with this width and height

thickRectangle :: (Number, Number, Number) -> Picture

A thick rectangle, with this width and height and line width

circle :: Number -> Picture

A thin circle, with this radius

solidCircle :: Number -> Picture

A solid circle, with this radius

thickCircle :: (Number, Number) -> Picture

A thick circle, with this radius and line width

arc :: (Number, Number, Number) -> Picture

A thin arc, starting and ending at these angles, with this radius

sector :: (Number, Number, Number) -> Picture

A solid sector of a circle (i.e., a pie slice) starting and ending at these angles, with this radius

thickArc :: (Number, Number, Number, Number) -> Picture

A thick arc, starting and ending at these angles, with this radius and line width

text :: Text -> Picture

A piece of text

styledText :: (Text, Font, TextStyle) -> Picture

A styled piece of text

colored :: (Picture, Color) -> Picture

A picture drawn entirely in this color.

coloured :: (Picture, Color) -> Picture

A picture drawn entirely in this color.

translated :: (Picture, Number, Number) -> Picture

A picture drawn translated in these directions.

scaled :: (Picture, Number, Number) -> Picture

A picture scaled by these factors.

dilated :: (Picture, Number, Number) -> Picture

A picture scaled by these factors.

rotated :: (Picture, Number) -> Picture

A picture rotated by this angle.

(&) :: 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

data Event

An event initiated by the user.

Values of this type represent events that the user triggers when using an interaction, defined with interactionOf.

Key events describe the key as Text. Most keys are represented by a single character text string, with the capital letter or other symbol from the key. Keys that don't correspond to a single character use longer names from the following list. Keep in mind that not all of these keys appear on all keyboards.

  • Up, Down, Left, and Right for the cursor keys.
  • F1, F2, etc. for function keys.
  • Backspace
  • Tab
  • Enter
  • Shift
  • Ctrl
  • Alt
  • Esc
  • PageUp
  • PageDown
  • End
  • Home
  • Insert
  • Delete
  • CapsLock
  • NumLock
  • ScrollLock
  • PrintScreen
  • Break
  • Separator
  • Cancel
  • Help

Instances

Eq Event 

data MouseButton :: *

Instances

Debugging

traced :: (a, Text) -> a

Entry points

type Program = IO ()

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

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