mirror of
https://github.com/mruby/mruby
synced 2026-06-08 16:11:16 +00:00
Yukihiro "Matz" Matsumoto
55 lines
2.0 KiB
Markdown
55 lines
2.0 KiB
Markdown
# mruby-struct
|
|
|
|
This mrbgem provides the `Struct` class, a convenient way to bundle a number of attributes together, much like Ruby's core `Struct` class. It allows you to create simple classes (structs) with a defined set of accessor methods for these attributes.
|
|
|
|
## Functionality
|
|
|
|
- Define new Struct classes with a specific set of members.
|
|
- Create instances of these Structs.
|
|
- Access and assign to struct members using accessor methods or by index/symbol.
|
|
- Iterate over members and values.
|
|
- Convert structs to Arrays or Hashes.
|
|
|
|
## Basic Usage
|
|
|
|
```ruby
|
|
# Define a new Struct class
|
|
Point = Struct.new(:x, :y)
|
|
|
|
# Create an instance of the Point struct
|
|
origin = Point.new(0, 0)
|
|
|
|
# Access attributes
|
|
puts origin.x # Output: 0
|
|
puts origin[:y] # Output: 0
|
|
|
|
# Set attributes
|
|
origin.x = 10
|
|
origin[:y] = 20
|
|
|
|
puts origin.inspect # Output: #<struct Point x=10, y=20>
|
|
|
|
# Another example
|
|
Customer = Struct.new("Customer", :name, :address)
|
|
joe = Customer.new("Joe Smith", "123 Maple, Anytown NC")
|
|
|
|
puts joe.name # Output: Joe Smith
|
|
puts joe.address # Output: 123 Maple, Anytown NC
|
|
```
|
|
|
|
## Available Methods
|
|
|
|
Instances of classes created with `Struct.new` have several useful methods, including:
|
|
|
|
- `members`: Returns an array of symbols representing the names of the instance variables.
|
|
- `each`: Calls a block for each attribute, passing the value.
|
|
- `each_pair`: Calls a block for each attribute, passing the name (symbol) and value.
|
|
- `select`: Returns an array containing values for which the block returns true.
|
|
- `to_a` / `values`: Returns an array containing the values of the struct.
|
|
- `to_h`: Returns a hash mapping member names (symbols) to their values.
|
|
- `length` / `size`: Returns the number of members in the struct.
|
|
- `dig`: Extracts a nested value specified by a sequence of keys.
|
|
- `==`, `eql?`: For comparing struct instances.
|
|
|
|
For more details on specific methods, please refer to the mruby documentation or the core Ruby `Struct` class documentation, as `mruby-struct` aims for compatibility.
|