# Constants

_Constants_ are definitions which provide a name and explicit type for some
[value](values.md). The `const` keyword (definition type) is used to define a
constant.

```
const weak_pi: Float64 is 3.14
const my_name: String  is "Pat"
```

In general:

```
const <name>: <type> is <value>
```

Since a constant is categorized as a [definition](general-syntax.md#definitions)
is uses the `is` keyword rather than the `:=` operator.

## Restrictions

Constants are subject to the following restrictions:

- Constants MUST refer to a literal value.
- Constants MUST have an explicit type.
- Constants MAY refer to a record instance.
- Constants CANNOT require a type constructor.
- Constants CANNOT refer to functions.
- Constants CANNOT refer to expressions.