diff options
Diffstat (limited to 'pack.rb')
| -rw-r--r-- | pack.rb | 31 |
1 files changed, 24 insertions, 7 deletions
@@ -148,10 +148,11 @@ end class String # call-seq: # str.unpack(format) -> anArray + # str.unpack(format, offset: anInteger) -> anArray # # Decodes <i>str</i> (which may contain binary data) according to the - # format string, returning an array of each value extracted. The - # format string consists of a sequence of single-character directives, + # format string, returning an array of each value extracted. + # The format string consists of a sequence of single-character directives, # summarized in the table at the end of this entry. # Each directive may be followed # by a number, indicating the number of times to repeat with this @@ -161,7 +162,15 @@ class String # exclamation mark (``<code>!</code>'') to use the underlying # platform's native size for the specified type; otherwise, it uses a # platform-independent consistent size. Spaces are ignored in the - # format string. See also String#unpack1, Array#pack. + # format string. + # + # The keyword <i>offset</i> can be given to start the decoding after skipping + # the specified amount of bytes: + # "abc".unpack("C*") # => [97, 98, 99] + # "abc".unpack("C*", offset: 2) # => [99] + # "abc".unpack("C*", offset: 4) # => offset outside of string (ArgumentError) + # + # See also String#unpack1, Array#pack. # # "abc \0\0abc \0\0".unpack('A6Z6') #=> ["abc", "abc "] # "abc \0\0".unpack('a3a3') #=> ["abc", " \000\000"] @@ -263,15 +272,23 @@ class String # * J, J! j, and j! are available since Ruby 2.3. # * Q_, Q!, q_, and q! are available since Ruby 2.1. # * I!<, i!<, I!>, and i!> are available since Ruby 1.9.3. - def unpack(fmt) - Primitive.pack_unpack(fmt) + def unpack(fmt, offset: 0) + Primitive.pack_unpack(fmt, offset) end # call-seq: # str.unpack1(format) -> obj + # str.unpack1(format, offset: anInteger) -> obj # # Decodes <i>str</i> (which may contain binary data) according to the # format string, returning the first value extracted. + # + # The keyword <i>offset</i> can be given to start the decoding after skipping + # the specified amount of bytes: + # "abc".unpack1("C*") # => 97 + # "abc".unpack1("C*", offset: 2) # => 99 + # "abc".unpack1("C*", offset: 4) # => offset outside of string (ArgumentError) + # # See also String#unpack, Array#pack. # # Contrast with String#unpack: @@ -287,7 +304,7 @@ class String # # Thus unpack1 is convenient, makes clear the intention and signals # the expected return value to those reading the code. - def unpack1(fmt) - Primitive.pack_unpack1(fmt) + def unpack1(fmt, offset: 0) + Primitive.pack_unpack1(fmt, offset) end end |