`class Table`

Represents a table of parsing rows for a command.

A table manages the collection of options, arguments, and nested commands that define how to parse a command line.

Definitions

`def self.nested(klass, parent = nil)`

Create a nested table that inherits from the parent class's table.

Signature

parameter　klass　Class: The command class to create a table for.
parameter　parent　Table | Nil: The parent table to inherit from.
returns　Table: The new table.

Implementation

def self.nested(klass, parent = nil)
	if klass.superclass.respond_to?(:table)
		parent = klass.superclass.table
	end
	
	self.new(parent, name: klass.name)
end

`def initialize(parent = nil, name: nil)`

Initialize a new table.

Signature

parameter　parent　Table | Nil: The parent table to inherit from.
parameter　name　String | Nil: The name of the command this table belongs to.

Implementation

def initialize(parent = nil, name: nil)
	@parent = parent
	@name = name
	@rows = {}
end

`def freeze`

Freeze this table.

Signature

returns　Table: The frozen table.

Implementation

def freeze
	return self if frozen?
	
	@rows.freeze
	
	super
end

`def [](key)`

Get a row by key.

Signature

parameter　key　Symbol: The key to look up.
returns　Object | Nil: The row with the given key.

Implementation

def [] key
	@rows[key]
end

`def each(&block)`

Iterate over each row.

Signature

yields　{|row| ...}: Each row in the table.

Implementation

def each(&block)
	@rows.each_value(&block)
end

`def <<(row)`

Add a row to the table.

Implementation

def << row
	if existing_row = @rows[row.key] and existing_row.respond_to?(:merge!)
		existing_row.merge!(row)
	else
		# In the above case where there is an existing row, but it doensn't support being merged, we overwrite it. This preserves order.
		@rows[row.key] = row.dup
	end
end

`def empty?`

Check if this table is empty.

Signature

returns　Boolean: True if this table and its parent are empty.

Implementation

def empty?
	@rows.empty? && @parent&.empty?
end

`def merge_into(table)`

Merge this table's rows into another table.

Signature

parameter　table　Table: The table to merge into.
returns　Table: The merged table.

Implementation

def merge_into(table)
	@parent&.merge_into(table)
	
	@rows.each_value do |row|
		table << row
	end
	
	return table
end

`def merged`

Get a merged table that includes parent rows.

Signature

returns　Table: The merged table.

Implementation

def merged
	if @parent.nil? or @parent.empty?
		return self
	else
		merge_into(self.class.new)
	end
end

`def usage`

Generate a usage string from all rows.

Signature

returns　String: The usage string.

Implementation

def usage
	@rows.each_value.collect(&:to_s).reject(&:empty?).join(" ")
end

`def parse(input, parent)`

Parse the input according to the rows in this table.

Signature

parameter　input　Array(String): The command-line arguments.
parameter　parent　Command: The parent command to store results in.

Implementation

def parse(input, parent)
	@rows.each do |key, row|
		next unless row.respond_to?(:parse)
		
		current = parent.send(key)
		
		result = row.parse(input, parent, current)
		if result != nil
			parent.public_send("#{row.key}=", result)
		end
	end
end