30 lines
767 B
Markdown
30 lines
767 B
Markdown
# 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.
|