return new FlatString.full(ns, elen, 0, elen)
end
+ # Interprets `self` as a big-endian positive integer.
+ #
+ # ~~~
+ # var b = "0102".hexdigest_to_bytes
+ # assert b.to_i == 258
+ # ~~~
+ #
+ # Nul bytes on the left are trimmed.
+ # 0 is returned for an empty Bytes object.
+ #
+ # ~~~
+ # assert "01".hexdigest_to_bytes.to_i == 1
+ # assert "0001".hexdigest_to_bytes.to_i == 1
+ #
+ # assert "0000".hexdigest_to_bytes.to_i == 0
+ # assert "00".hexdigest_to_bytes.to_i == 0
+ # assert "".hexdigest_to_bytes.to_i == 0
+ # ~~~
+ #
+ # `Int::to_bytes` is a loosely reverse method.
+ #
+ # ~~~
+ # assert b.to_i.to_bytes == b
+ # assert (b.to_i + 1).to_bytes.hexdigest == "0103"
+ # assert "0001".hexdigest_to_bytes.to_i.to_bytes.hexdigest == "01"
+ # ~~~
+ #
+ # Warning: `Int` might overflow for bytes with more than 60 bits.
+ fun to_i: Int do
+ var res = 0
+ var i = 0
+ while i < length do
+ res *= 256
+ res += self[i].to_i
+ i += 1
+ end
+ return res
+ end
+
# var b = new Bytes.with_capacity(1)
# b[0] = 101u8
# assert b.to_s == "e"
redef fun item do return tgt[index]
end
+redef class Int
+ # A big-endian representation of self.
+ #
+ # ~~~
+ # assert 1.to_bytes.hexdigest == "01"
+ # assert 255.to_bytes.hexdigest == "FF"
+ # assert 256.to_bytes.hexdigest == "0100"
+ # assert 65535.to_bytes.hexdigest == "FFFF"
+ # assert 65536.to_bytes.hexdigest == "010000"
+ # ~~~
+ #
+ # For 0, a Bytes object with single nul byte is returned (instead of an empty Bytes object).
+ #
+ # ~~~
+ # assert 0.to_bytes.hexdigest == "00"
+ # ~~~
+ #
+ # `Bytes::to_i` can be used to do the reverse operation.
+ #
+ # ~~~
+ # assert 1234.to_bytes.to_i == 1234
+ # ~~~
+ #
+ # Require self >= 0
+ fun to_bytes: Bytes do
+ if self == 0 then return "\0".to_bytes
+ assert self > 0
+
+ # Compute the len (log256)
+ var len = 1
+ var max = 256
+ while self >= max do
+ len += 1
+ max *= 256
+ end
+
+ # Allocate the buffer
+ var res = new Bytes.with_capacity(len)
+ for i in [0..len[ do res[i] = 0u8
+
+ # Fill it starting with the end
+ var i = len
+ var sum = self
+ while i > 0 do
+ i -= 1
+ res[i] = (sum % 256).to_b
+ sum /= 256
+ end
+ return res
+ end
+end
+
redef class Text
# Returns a mutable copy of `self`'s bytes
#
# assert "0B1F4D".hexdigest_to_bytes == [0x0Bu8, 0x1Fu8, 0x4Du8]
# assert "0B1F4D".hexdigest_to_bytes.hexdigest == "0B1F4D"
#
- # REQUIRE: `self` is a valid hexdigest and hexdigest.length % 2 == 0
+ # Characters that are not hexadecimal digits are ignored.
+ #
+ # assert "z0B1 F4\nD".hexdigest_to_bytes.hexdigest == "0B1F4D"
+ # assert "\\x0b1 \\xf4d".hexdigest_to_bytes.hexdigest == "0B1F4D"
+ #
+ # When the number of hexadecimal digit is not even, then a leading 0 is
+ # implicitly considered to fill the left byte (the most significant one).
+ #
+ # assert "1".hexdigest_to_bytes.hexdigest == "01"
+ # assert "FFF".hexdigest_to_bytes.hexdigest == "0FFF"
+ #
+ # `Bytes::hexdigest` is a loosely reverse method since its
+ # results contain only pairs of uppercase hexadecimal digits.
+ #
+ # assert "ABCD".hexdigest_to_bytes.hexdigest == "ABCD"
+ # assert "a b c".hexdigest_to_bytes.hexdigest == "0ABC"
fun hexdigest_to_bytes: Bytes do
var b = bytes
- var pos = 0
var max = bytelen
- var ret = new Bytes.with_capacity(max / 2)
+
+ var dlength = 0 # Number of hex digits
+ var pos = 0
+ while pos < max do
+ var c = b[pos]
+ if c.is_valid_hexdigit then dlength += 1
+ pos += 1
+ end
+
+ # Allocate the result buffer
+ var ret = new Bytes.with_capacity((dlength+1) / 2)
+
+ var i = (dlength+1) % 2 # current hex digit (1=high, 0=low)
+ var byte = 0u8 # current accumulated byte value
+
+ pos = 0
while pos < max do
- ret.add((b[pos].hexdigit_to_byteval << 4) |
- b[pos + 1].hexdigit_to_byteval)
- pos += 2
+ var c = b[pos]
+ if c.is_valid_hexdigit then
+ byte = byte << 4 | c.hexdigit_to_byteval
+ i -= 1
+ if i < 0 then
+ # Last digit known: store and restart
+ ret.add byte
+ i = 1
+ byte = 0u8
+ end
+ end
+ pos += 1
end
return ret
end
nitlanguage / nit.git / blobdiff