Safe Haskell	None
Language	Haskell98

Hascal

Description

Hascal is a simple, minimalistic, tiny calculator library and program.

Hascal only understands single-character operators.
Hascal only understands infix operators.
Hascal does not understand parantheses.
_ is hard-coded as single prefix for negating numbers.
By default, Hascal understands the operators +, -, *, /, ^, and ? (logarithm).
By default, Hascal understands the constants pi, e, and i.
Using Hascal as a library, you can add new operators and new constants using a configuration data type.

The hascal executable program is easy to use. In a shell, type:

>>> hascal 1+2-3*4/5^6?7
-1.7263530417152033

Given a configuration, the hascal function similarly evaluates an expression of type String. In a Haskell interpreter like GHCI, type:

>>> hascal def "1+2-3*4/5^6?7"
Right (0.2736469582847967 :+ 0.0)

>>> hascal def "1++2"
Left "Error at \"\"."

Synopsis

Documentation

data Config t Source #

A configuration. def is the default configuration.

Constructors

Config
Fields operators :: [Operator t] A list of operators. The order in this list also determines the order of evaluation. constants :: [Constant t] A list of constants.

Instances

(Read t, RealFloat t) => Default (Config t) Source #
Methods def :: Config t #

class Default a where #

A class for types with a default value.

Methods

def :: a #

The default value for this type.

Instances

Default Double
Methods def :: Double #
Default Float
Methods def :: Float #
Default Int
Methods def :: Int #
Default Int8
Methods def :: Int8 #
Default Int16
Methods def :: Int16 #
Default Int32
Methods def :: Int32 #
Default Int64
Methods def :: Int64 #
Default Integer
Methods def :: Integer #
Default Ordering
Methods def :: Ordering #
Default Word
Methods def :: Word #
Default Word8
Methods def :: Word8 #
Default Word16
Methods def :: Word16 #
Default Word32
Methods def :: Word32 #
Default Word64
Methods def :: Word64 #
Default ()
Methods def :: () #
Default CShort
Methods def :: CShort #
Default CUShort
Methods def :: CUShort #
Default CInt
Methods def :: CInt #
Default CUInt
Methods def :: CUInt #
Default CLong
Methods def :: CLong #
Default CULong
Methods def :: CULong #
Default CLLong
Methods def :: CLLong #
Default CULLong
Methods def :: CULLong #
Default CFloat
Methods def :: CFloat #
Default CDouble
Methods def :: CDouble #
Default CPtrdiff
Methods def :: CPtrdiff #
Default CSize
Methods def :: CSize #
Default CSigAtomic
Methods def :: CSigAtomic #
Default CClock
Methods def :: CClock #
Default CTime
Methods def :: CTime #
Default CUSeconds
Methods def :: CUSeconds #
Default CSUSeconds
Methods def :: CSUSeconds #
Default CIntPtr
Methods def :: CIntPtr #
Default CUIntPtr
Methods def :: CUIntPtr #
Default CIntMax
Methods def :: CIntMax #
Default CUIntMax
Methods def :: CUIntMax #
Default All
Methods def :: All #
Default Any
Methods def :: Any #
Default [a]
Methods def :: [a] #
Default (Maybe a)
Methods def :: Maybe a #
Integral a => Default (Ratio a)
Methods def :: Ratio a #
Default a => Default (IO a)
Methods def :: IO a #
(Default a, RealFloat a) => Default (Complex a)
Methods def :: Complex a #
Default a => Default (Dual a)
Methods def :: Dual a #
Default (Endo a)
Methods def :: Endo a #
Num a => Default (Sum a)
Methods def :: Sum a #
Num a => Default (Product a)
Methods def :: Product a #
Default (First a)
Methods def :: First a #
Default (Last a)
Methods def :: Last a #
(Read t, RealFloat t) => Default (Config t) #
Methods def :: Config t #
Default r => Default (e -> r)
Methods def :: e -> r #
(Default a, Default b) => Default (a, b)
Methods def :: (a, b) #
(Default a, Default b, Default c) => Default (a, b, c)
Methods def :: (a, b, c) #
(Default a, Default b, Default c, Default d) => Default (a, b, c, d)
Methods def :: (a, b, c, d) #
(Default a, Default b, Default c, Default d, Default e) => Default (a, b, c, d, e)
Methods def :: (a, b, c, d, e) #
(Default a, Default b, Default c, Default d, Default e, Default f) => Default (a, b, c, d, e, f)
Methods def :: (a, b, c, d, e, f) #
(Default a, Default b, Default c, Default d, Default e, Default f, Default g) => Default (a, b, c, d, e, f, g)
Methods def :: (a, b, c, d, e, f, g) #

hascal :: (Read t, RealFloat t) => Config t -> String -> Result t Source #

Given a configuration and a String-expression, returns Either a String containing an error message; or a Complex number.

showHascal :: (Show t, Read t, RealFloat t) => Config t -> String -> String Source #

Given a configuration and a String-expression, returns a String containing the error message or the resulting complex number.

showNumber :: (Show t, RealFloat t) => Complex t -> String Source #

Show a Complex number a little bit more human-readable by matching both the real and the imaginery part against zero and one.