96 lines
2.6 KiB
Markdown
96 lines
2.6 KiB
Markdown
---
|
|
id: functions
|
|
title: Functions
|
|
---
|
|
|
|
Writing code is fun as long as it doesn't get out of hand. To make sure our code doesn't turn into spaghetti we can group some logic into functions.
|
|
|
|
## Instruction blocks
|
|
|
|
With `block`(s) you can wrap *instructions* and *expressions* into an isolated scope.
|
|
Each `block` needs to include at least one `instruction`, or a *placeholder* instruction called `skip`.
|
|
|
|
<!--DOCUSAURUS_CODE_TABS-->
|
|
<!--Pascaligo-->
|
|
|
|
```pascaligo
|
|
// shorthand syntax
|
|
block { skip }
|
|
// verbose syntax
|
|
begin
|
|
skip
|
|
end
|
|
```
|
|
|
|
<!--END_DOCUSAURUS_CODE_TABS-->
|
|
|
|
## Defining a function
|
|
|
|
<!--DOCUSAURUS_CODE_TABS-->
|
|
<!--Pascaligo-->
|
|
|
|
Functions in PascaLIGO are defined using the `function` keyword followed by their `name`, `parameters` and `return` type definitions.
|
|
|
|
Here's how you define a basic function that accepts two `ints` and returns a single `int`:
|
|
|
|
|
|
```pascaligo
|
|
function add(const a: int; const b: int): int is
|
|
begin
|
|
const result: int = a + b;
|
|
end with result;
|
|
```
|
|
|
|
The function body consists of two parts:
|
|
|
|
- `block {<code>}` - logic of the function
|
|
- `with <value>` - the return value of the function
|
|
|
|
#### Blockless functions
|
|
|
|
Functions that can contain all of their logic into a single instruction/expression, can be defined without the surrounding `block`.
|
|
Instead, you can inline the necessary logic directly, like this:
|
|
|
|
```pascaligo
|
|
function add(const a: int; const b: int): int is a + b
|
|
```
|
|
|
|
<!--Cameligo-->
|
|
|
|
Functions in CameLIGO are defined using the `let` keyword, like value bindings.
|
|
The difference is that after the value name a list of function parameters is provided,
|
|
along with a return type.
|
|
|
|
Here's how you define a basic function that accepts two `ints` and returns an `int` as well:
|
|
|
|
```cameligo
|
|
let add (a: int) (b: int) : int = a + b
|
|
```
|
|
|
|
The function body is a series of expressions, which are evaluated to give the return
|
|
value.
|
|
|
|
<!--END_DOCUSAURUS_CODE_TABS-->
|
|
|
|
<!--DOCUSAURUS_CODE_TABS-->
|
|
<!--Pascaligo-->
|
|
```pascaligo
|
|
const increment : (int -> int) = (function (const i : int) : int is i + 1);
|
|
// a = 2
|
|
const a: int = increment(1);
|
|
```
|
|
<!--END_DOCUSAURUS_CODE_TABS-->
|
|
|
|
## Anonymous functions
|
|
|
|
Functions without a name, also known as anonymous functions are useful in cases when you want to pass the function as an argument or assign it to a key in a record/map.
|
|
|
|
Here's how to define an anonymous function assigned to a variable `increment`, with it's appropriate function type signature.
|
|
<!--DOCUSAURUS_CODE_TABS-->
|
|
<!--Pascaligo-->
|
|
```pascaligo
|
|
const increment : (int -> int) = (function (const i : int) : int is i + 1);
|
|
// a = 2
|
|
const a: int = increment(1);
|
|
```
|
|
<!--END_DOCUSAURUS_CODE_TABS--> |