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|
# frozen_string_literal: true
require "forwardable"
module TTY
class Reader
# A class responsible for storing a history of all lines entered by
# user when interacting with shell prompt.
#
# @api private
class History
include Enumerable
extend Forwardable
# Default maximum size
DEFAULT_SIZE = 32 << 4
# Default exclude
DEFAULT_EXCLUDE = ->(line) { line.chomp == "" }
def_delegators :@history, :size, :length, :to_s, :inspect
# Set and retrieve the maximum size of the buffer
attr_accessor :max_size
# The current index
#
# @return [Integer]
#
# @api private
attr_reader :index
# Decides whether or not to allow cycling through stored lines.
#
# @return [Boolean]
#
# @api public
attr_accessor :cycle
# Decides wether or not duplicate lines are stored.
#
# @return [Boolean]
#
# @api public
attr_accessor :duplicates
# Dictates which lines are stored.
#
# @return [Proc]
#
# @public
attr_accessor :exclude
# Create a History buffer
#
# @param [Integer] max_size
# the maximum size for history buffer
# @param [Boolean] cycle
# whether or not the history should cycle, false by default
# @param [Boolean] duplicates
# whether or not to store duplicates, true by default
# @param [Boolean] exclude
# a Proc to exclude items from storing in history
#
# @api public
def initialize(max_size = DEFAULT_SIZE, duplicates: true, cycle: false,
exclude: DEFAULT_EXCLUDE)
@max_size = max_size
@index = nil
@history = []
@duplicates = duplicates
@exclude = exclude
@cycle = cycle
yield self if block_given?
end
# Iterates over history lines
#
# @api public
def each(&block)
if block_given?
@history.each(&block)
else
@history.to_enum
end
end
# Add the last typed line to history buffer
#
# @param [String] line
#
# @api public
def push(line)
@history.delete(line) unless @duplicates
return if line.to_s.empty? || @exclude[line]
@history.shift if size >= max_size
@history << line
@index = @history.size - 1
self
end
alias << push
# Move the pointer to the next line in the history
#
# @api public
def next
return if size.zero?
if @index == size - 1
@index = 0 if @cycle
else
@index += 1
end
end
def next?
size > 0 && !(@index == size - 1 && !@cycle)
end
# Move the pointer to the previous line in the history
def previous
return if size.zero?
if @index.zero?
@index = size - 1 if @cycle
else
@index -= 1
end
end
def previous?
size > 0 && !(@index < 0 && !@cycle)
end
# Return line at the specified index
#
# @raise [IndexError] index out of range
#
# @api public
def [](index)
if index < 0
index += @history.size if index < 0
end
line = @history[index]
if line.nil?
raise IndexError, "invalid index"
end
line.dup
end
# Get current line
#
# @api public
def get
return if size.zero?
self[@index]
end
# Empty all history lines
#
# @api public
def clear
@history.clear
@index = 0
end
end # History
end # Reader
end # TTY
|
