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require 'active_support/multibyte'
class String
# If you pass a single Fixnum, returns a substring of one character at that
# position. The first character of the string is at position 0, the next at
# position 1, and so on. If a range is supplied, a substring containing
# characters at offsets given by the range is returned. In both cases, if an
# offset is negative, it is counted from the end of the string. Returns nil
# if the initial offset falls outside the string. Returns an empty string if
# the beginning of the range is greater than the end of the string.
#
# str = "hello"
# str.at(0) #=> "h"
# str.at(1..3) #=> "ell"
# str.at(-2) #=> "l"
# str.at(-2..-1) #=> "lo"
# str.at(5) #=> nil
# str.at(5..-1) #=> ""
#
# If a Regexp is given, the matching portion of the string is returned.
# If a String is given, that given string is returned if it occurs in
# the string. In both cases, nil is returned if there is no match.
#
# str = "hello"
# str.at(/lo/) #=> "lo"
# str.at(/ol/) #=> nil
# str.at("lo") #=> "lo"
# str.at("ol") #=> nil
def at(position)
self[position]
end
def from(position)
self[position..-1]
end
# Returns a substring from the beginning of the string to the given position.
# If the position is negative, it is counted from the end of the string.
#
# str = "hello"
# str.to(0) #=> "h"
# str.to(3) #=> "hell"
# str.to(-2) #=> "hell"
#
# You can mix it with +from+ method and do fun things like:
#
# str = "hello"
# str.from(0).to(-1) #=> "hello"
# str.from(1).to(-2) #=> "ell"
def to(position)
self[0..position]
end
def first(limit = 1)
if limit == 0
''
elsif limit >= size
self
else
to(limit - 1)
end
end
def last(limit = 1)
if limit == 0
''
elsif limit >= size
self
else
from(-limit)
end
end
end
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