Basic Types

Booleans: Bool

Integers: Int, Integer

Reals: Float, Double

Characters: Char

Booleans

Literals: False and True

not :: Bool -> Bool             -- negation
(||) :: Bool -> Bool -> Bool    -- disjunction
(&&) :: Bool -> Bool -> Bool    -- conjunction

Examples:

not True                -- False
not False               -- True

True || False           -- True
True && False           -- False

(False || True) && True -- True
not (not True)          -- True
not not True            -- error

We cannot pass another function as the input to the function

Integers

Type:

Int: Integers of 64 bits
Integer: for longer numbers

Literals: 15, (-22), 857563543132

Operations: +, -, *, div, mod, rem, ^

Relational operators: <, >, <=, >=, ==, /= <- Inequality (no !=)

Examples:

ghci> 3 + 4 * 5
23
ghci> (3 + 4) * 5
35
ghci> 2^10
1024
ghci> 3 + 1 /= 4
False
ghci> div 11 2
5
ghci> mod 11 2
1
ghci> rem 11 2
1
ghci> mod (-11) 2
1
ghci> rem (-11) 2
-1

mod: result always >= 0 rem: takes the sign of the dividend

Reals

Type:

Float: 32-bit floating point reals
Double: 64-bit floating point reals

Literals: 3.14, 1e-9, -3.0

Operations: +, -, *, /, **

Relational operators: <, >, <=, >=, ==, /=

Integer to Real conversion: fromIntegral

Real to Integer conversion: round, floor, ceiling

Examples:

ghci> round 3.6
4
ghci> round (-3.6)
-4
ghci> map round [3.5, 4.5, 5.5, 6.5]
[4,4,6,6]

Round: rounds to the closest number.

Same code in C++:

std::vector<double> nums = {3.5, 4.5, 5.5, 6.5};
std::vector<int> rounded;
std::transform(nums.begin(), nums.end(), std::back_inserter(rounded), 
               [](double x) { return std::round(x); });

ghci> map ceiling [2.1, 2.2, 2.6, 2.9]
[3,3,3,3]
ghci> map floor [2.1, 2.2, 2.6, 2.9]
[2,2,2,2]

ghci> 10.0/3.0
3.3333333333333335
ghci> 2.0 ** 3.0
8.0
ghci> fromIntegral 4
4