| Safe Haskell | Trustworthy |
|---|---|
| Language | Haskell98 |
Test.QuickCheck.Modifiers
Description
Modifiers for test data.
These types do things such as restricting the kind of test data that can be generated. They can be pattern-matched on in properties as a stylistic alternative to using explicit quantification.
Examples:
-- Functions cannot be shown (but see Test.QuickCheck.Function) prop_TakeDropWhile (Blindp) (xs :: [A]) = takeWhile p xs ++ dropWhile p xs == xs
prop_TakeDrop (NonNegativen) (xs :: [A]) = take n xs ++ drop n xs == xs
-- cycle does not work for empty lists prop_Cycle (NonNegativen) (NonEmpty(xs :: [A])) = take n (cycle xs) == take n (xs ++ cycle xs)
-- Instead offorAllorderedListprop_Sort (Ordered(xs :: [OrdA])) = sort xs == xs
- newtype Blind a = Blind {
- getBlind :: a
- newtype Fixed a = Fixed {
- getFixed :: a
- newtype OrderedList a = Ordered {
- getOrdered :: [a]
- newtype NonEmptyList a = NonEmpty {
- getNonEmpty :: [a]
- newtype Positive a = Positive {
- getPositive :: a
- newtype NonZero a = NonZero {
- getNonZero :: a
- newtype NonNegative a = NonNegative {
- getNonNegative :: a
- newtype Large a = Large {
- getLarge :: a
- newtype Small a = Small {
- getSmall :: a
- data Smart a = Smart Int a
- newtype Shrink2 a = Shrink2 {
- getShrink2 :: a
- data Shrinking s a = Shrinking s a
- class ShrinkState s a where
- shrinkInit :: a -> s
- shrinkState :: a -> s -> [(a, s)]
Type-level modifiers for changing generator behavior
Blind x: as x, but x does not have to be in the Show class.
Fixed x: as x, but will not be shrunk.
newtype OrderedList a Source
Ordered xs: guarantees that xs is ordered.
Constructors
| Ordered | |
Fields
| |
Instances
| Functor OrderedList | |
| Eq a => Eq (OrderedList a) | |
| Ord a => Ord (OrderedList a) | |
| Read a => Read (OrderedList a) | |
| Show a => Show (OrderedList a) | |
| (Ord a, Arbitrary a) => Arbitrary (OrderedList a) |
newtype NonEmptyList a Source
NonEmpty xs: guarantees that xs is non-empty.
Constructors
| NonEmpty | |
Fields
| |
Instances
| Functor NonEmptyList | |
| Eq a => Eq (NonEmptyList a) | |
| Ord a => Ord (NonEmptyList a) | |
| Read a => Read (NonEmptyList a) | |
| Show a => Show (NonEmptyList a) | |
| Arbitrary a => Arbitrary (NonEmptyList a) |
Positive x: guarantees that x > 0.
Constructors
| Positive | |
Fields
| |
NonZero x: guarantees that x /= 0.
Constructors
| NonZero | |
Fields
| |
newtype NonNegative a Source
NonNegative x: guarantees that x >= 0.
Constructors
| NonNegative | |
Fields
| |
Instances
| Functor NonNegative | |
| Enum a => Enum (NonNegative a) | |
| Eq a => Eq (NonNegative a) | |
| Ord a => Ord (NonNegative a) | |
| Read a => Read (NonNegative a) | |
| Show a => Show (NonNegative a) | |
| (Num a, Ord a, Arbitrary a) => Arbitrary (NonNegative a) |
Large x: by default, QuickCheck generates Ints drawn from a small
range. Large Int gives you values drawn from the entire range instead.
Small x: generates values of x drawn from a small range.
The opposite of Large.
Smart _ x: tries a different order when shrinking.
Shrink2 x: allows 2 shrinking steps at the same time when shrinking x
Constructors
| Shrink2 | |
Fields
| |
Shrinking _ x: allows for maintaining a state during shrinking.
Constructors
| Shrinking s a |
class ShrinkState s a where Source