Class: Prism::Pack::Directive
Relationships & Source Files | |
Inherits: | Object |
Defined in: | lib/prism/pack.rb, prism/api_pack.c |
Overview
A directive in the pack template language.
Constant Summary
-
ENDIAN_DESCRIPTIONS =
The descriptions of the various types of endianness.
{ AGNOSTIC_ENDIAN: "agnostic", LITTLE_ENDIAN: "little-endian (VAX)", BIG_ENDIAN: "big-endian (network)", NATIVE_ENDIAN: "native-endian", ENDIAN_NA: "n/a" }
-
SIGNED_DESCRIPTIONS =
The descriptions of the various types of signedness.
{ UNSIGNED: "unsigned", SIGNED: "signed", SIGNED_NA: "n/a" }
-
SIZE_DESCRIPTIONS =
The descriptions of the various types of sizes.
{ SIZE_SHORT: "short", SIZE_INT: "int-width", SIZE_LONG: "long", SIZE_LONG_LONG: "long long", SIZE_8: "8-bit", SIZE_16: "16-bit", SIZE_32: "32-bit", SIZE_64: "64-bit", SIZE_P: "pointer-width" }
Class Method Summary
-
.new(version, variant, source, type, signed, endian, size, length_type, length) ⇒ Directive
constructor
Initialize a new directive with the given values.
Instance Attribute Summary
-
#endian
readonly
The type of endianness of the directive.
-
#length
readonly
The length of this directive (used for integers).
-
#length_type
readonly
The length type of this directive (used for integers).
-
#signed
readonly
The type of signedness of the directive.
-
#size
readonly
The size of the directive.
-
#source
readonly
A byteslice of the source string that this directive represents.
-
#type
readonly
The type of the directive.
-
#variant
readonly
A symbol representing whether or not we are packing or unpacking.
-
#version
readonly
A symbol representing the version of Ruby.
Instance Method Summary
-
#describe
Provide a human-readable description of the directive.
Constructor Details
.new(version, variant, source, type, signed, endian, size, length_type, length) ⇒ Directive
Initialize a new directive with the given values.
Instance Attribute Details
#endian (readonly)
The type of endianness of the directive.
# File 'lib/prism/pack.rb', line 76
attr_reader :endian
#length (readonly)
The length of this directive (used for integers).
# File 'lib/prism/pack.rb', line 85
attr_reader :length
#length_type (readonly)
The length type of this directive (used for integers).
# File 'lib/prism/pack.rb', line 82
attr_reader :length_type
#signed (readonly)
The type of signedness of the directive.
# File 'lib/prism/pack.rb', line 73
attr_reader :signed
#size (readonly)
The size of the directive.
# File 'lib/prism/pack.rb', line 79
attr_reader :size
#source (readonly)
A byteslice of the source string that this directive represents.
# File 'lib/prism/pack.rb', line 67
attr_reader :source
#type (readonly)
The type of the directive.
# File 'lib/prism/pack.rb', line 70
attr_reader :type
#variant (readonly)
A symbol representing whether or not we are packing or unpacking.
# File 'lib/prism/pack.rb', line 64
attr_reader :variant
#version (readonly)
A symbol representing the version of Ruby.
# File 'lib/prism/pack.rb', line 61
attr_reader :version
Instance Method Details
#describe
Provide a human-readable description of the directive.
# File 'lib/prism/pack.rb', line 130
def describe case type when SPACE "whitespace" when COMMENT "comment" when INTEGER if size == SIZE_8 base = "#{SIGNED_DESCRIPTIONS[signed]} #{SIZE_DESCRIPTIONS[size]} integer" else base = "#{SIGNED_DESCRIPTIONS[signed]} #{SIZE_DESCRIPTIONS[size]} #{ENDIAN_DESCRIPTIONS[endian]} integer" end case length_type when LENGTH_FIXED if length > 1 base + ", x#{length}" else base end when LENGTH_MAX base + ", as many as possible" end when UTF8 "UTF-8 character" when BER "BER-compressed integer" when FLOAT "#{SIZE_DESCRIPTIONS[size]} #{ENDIAN_DESCRIPTIONS[endian]} float" when STRING_SPACE_PADDED "arbitrary binary string (space padded)" when STRING_NULL_PADDED "arbitrary binary string (null padded, count is width)" when STRING_NULL_TERMINATED "arbitrary binary string (null padded, count is width), except that null is added with *" when STRING_MSB "bit string (MSB first)" when STRING_LSB "bit string (LSB first)" when STRING_HEX_HIGH "hex string (high nibble first)" when STRING_HEX_LOW "hex string (low nibble first)" when STRING_UU "UU-encoded string" when STRING_MIME "quoted printable, MIME encoding" when STRING_BASE64 "base64 encoded string" when STRING_FIXED "pointer to a structure (fixed-length string)" when STRING_POINTER "pointer to a null-terminated string" when MOVE "move to absolute position" when BACK "back up a byte" when NULL "null byte" else raise end end