typexpr:`'`

ident|`(`

typexpr`)`

|typexpr`->`

typexpr|typexpr{`*`

typexpr}+|typeconstr|typexprtypeconstr|`(`

typexpr{`,`

typexpr}`)`

typeconstr

The table below shows the relative precedences and associativity of operators and non-closed type constructions. The constructions with higher precedences come first.

Operator | Associativity |
---|---|

Type constructor application | -- |

* | -- |

-> | right |

Type expressions denote types in definitions of data types as well as in type constraints over patterns and expressions.

The type expression `'`

*ident* stands for the type variable named
*ident*. In data type definitions, type variables are names for the
data type parameters. In type constraints, they represent unspecified
types that can be instantiated by any type to satisfy the type
constraint.

The type expression `(`

*typexpr* `)`

denotes the same type as
*typexpr*.

The type expression *typexpr*_{1} `->`

*typexpr*_{2} denotes the type of
functions mapping arguments of type *typexpr*_{1} to results of type
*typexpr*_{2}.

The type expression *typexpr*_{1} `*`

...`*`

*typexpr*_{n}
denotes the type of tuples whose elements belong to types *typexpr*_{1},...*typexpr*_{n} respectively.

Type constructors with no parameter, as in *typeconstr*, are type
expressions.

The type expression *typexpr* *typeconstr*, where *typeconstr* is a type
constructor with one parameter, denotes the application of the unary type
constructor *typeconstr* to the type *typexpr*.

The type expression *(**typexpr*_{1},...,*typexpr*_{n}*)* *typeconstr*, where
*typeconstr* is a type constructor with n parameters, denotes the
application of the n-ary type constructor *typeconstr* to the types
*typexpr*_{1} through *typexpr*_{n}.