fun substring(from: Int, count: Int): SELFTYPE is abstract
# Iterates on the substrings of self if any
- fun substrings: Iterator[FlatText] is abstract
+ private fun substrings: Iterator[FlatText] is abstract
# Is the current Text empty (== "")
#
# If `self` contains only digits and alpha <= 'f', return the corresponding integer.
#
# assert "ff".to_hex == 255
- fun to_hex: Int do return a_to(16)
+ fun to_hex(pos, ln: nullable Int): Int do
+ var res = 0
+ if pos == null then pos = 0
+ if ln == null then ln = length - pos
+ var max = pos + ln
+ for i in [pos .. max[ do
+ res <<= 4
+ res += self[i].from_hex
+ end
+ return res
+ end
# If `self` contains only digits <= '7', return the corresponding integer.
#
return res.to_s
end
+ # Returns `self` with all characters escaped with their UTF-16 representation
+ #
+ # assert "Aรจใ๐".escape_to_utf16 == "\\u0041\\u00e8\\u3042\\ud800\\udfd3"
+ fun escape_to_utf16: String do
+ var buf = new Buffer
+ for i in chars do buf.append i.escape_to_utf16
+ return buf.to_s
+ end
+
+ # Returns the Unicode char escaped by `self`
+ #
+ # assert "\\u0041".from_utf16_escape == 'A'
+ # assert "\\ud800\\udfd3".from_utf16_escape == '๐'
+ # assert "\\u00e8".from_utf16_escape == 'รจ'
+ # assert "\\u3042".from_utf16_escape == 'ใ'
+ fun from_utf16_escape(pos, ln: nullable Int): Char do
+ if pos == null then pos = 0
+ if ln == null then ln = length - pos
+ if ln < 6 then return 0xFFFD.code_point
+ var cp = from_utf16_digit(pos + 2)
+ if cp < 0xD800 then return cp.code_point
+ if cp > 0xDFFF then return cp.code_point
+ if cp > 0xDBFF then return 0xFFFD.code_point
+ if ln == 6 then return 0xFFFD.code_point
+ if ln < 12 then return 0xFFFD.code_point
+ cp <<= 16
+ cp += from_utf16_digit(pos + 8)
+ var cplo = cp & 0xFFFF
+ if cplo < 0xDC00 then return 0xFFFD.code_point
+ if cplo > 0xDFFF then return 0xFFFD.code_point
+ return cp.from_utf16_surr.code_point
+ end
+
+ # Returns a UTF-16 escape value
+ #
+ # var s = "\\ud800\\udfd3"
+ # assert s.from_utf16_digit(2) == 0xD800
+ # assert s.from_utf16_digit(8) == 0xDFD3
+ fun from_utf16_digit(pos: nullable Int): Int do
+ if pos == null then pos = 0
+ return to_hex(pos, 4)
+ end
+
# Encode `self` to percent (or URL) encoding
#
# assert "aBc09-._~".to_percent_encoding == "aBc09-._~"
return s.plain_to_s
end
+ # Return the Levenshtein distance between two strings
+ #
+ # ~~~
+ # assert "abcd".levenshtein_distance("abcd") == 0
+ # assert "".levenshtein_distance("abcd") == 4
+ # assert "abcd".levenshtein_distance("") == 4
+ # assert "abcd".levenshtein_distance("xyz") == 4
+ # assert "abcd".levenshtein_distance("xbdy") == 3
+ # ~~~
+ fun levenshtein_distance(other: String): Int
+ do
+ var slen = self.length
+ var olen = other.length
+
+ # fast cases
+ if slen == 0 then return olen
+ if olen == 0 then return slen
+ if self == other then return 0
+
+ # previous row of distances
+ var v0 = new Array[Int].with_capacity(olen+1)
+
+ # current row of distances
+ var v1 = new Array[Int].with_capacity(olen+1)
+
+ for j in [0..olen] do
+ # prefix insert cost
+ v0[j] = j
+ end
+
+ for i in [0..slen[ do
+
+ # prefix delete cost
+ v1[0] = i + 1
+
+ for j in [0..olen[ do
+ # delete cost
+ var cost1 = v1[j] + 1
+ # insert cost
+ var cost2 = v0[j + 1] + 1
+ # same char cost (+0)
+ var cost3 = v0[j]
+ # change cost
+ if self[i] != other[j] then cost3 += 1
+ # keep the min
+ v1[j+1] = cost1.min(cost2).min(cost3)
+ end
+
+ # Switch columns:
+ # * v1 become v0 in the next iteration
+ # * old v0 is reused as the new v1
+ var tmp = v1
+ v1 = v0
+ v0 = tmp
+ end
+
+ return v0[olen]
+ end
+
# Copies `n` bytes from `self` at `src_offset` into `dest` starting at `dest_offset`
#
# Basically a high-level synonym of NativeString::copy_to
end
# All kinds of array-based text representations.
-private abstract class FlatText
+abstract class FlatText
super Text
# Underlying C-String (`char*`)
# assert 'ใพ'.bytes == [0xE3u8, 0x81u8, 0xBEu8]
fun bytes: SequenceRead[Byte] do return to_s.bytes
+ # Is `self` an UTF-16 surrogate pair ?
+ fun is_surrogate: Bool do
+ var cp = code_point
+ return cp >= 0xD800 and cp <= 0xDFFF
+ end
+
# Length of `self` in a UTF-8 String
private fun u8char_len: Int do
var c = self.code_point
return ns.to_s_with_length(ln)
end
+ # Returns `self` escaped to UTF-16
+ #
+ # i.e. Represents `self`.`code_point` using UTF-16 codets escaped
+ # with a `\u`
+ #
+ # assert 'A'.escape_to_utf16 == "\\u0041"
+ # assert 'รจ'.escape_to_utf16 == "\\u00e8"
+ # assert 'ใ'.escape_to_utf16 == "\\u3042"
+ # assert '๐'.escape_to_utf16 == "\\ud800\\udfd3"
+ fun escape_to_utf16: String do
+ var cp = code_point
+ var buf: Buffer
+ if cp < 0xD800 or (cp >= 0xE000 and cp <= 0xFFFF) then
+ buf = new Buffer.with_cap(6)
+ buf.append("\\u0000")
+ var hx = cp.to_hex
+ var outid = 5
+ for i in hx.chars.reverse_iterator do
+ buf[outid] = i
+ outid -= 1
+ end
+ else
+ buf = new Buffer.with_cap(12)
+ buf.append("\\u0000\\u0000")
+ var lo = (((cp - 0x10000) & 0x3FF) + 0xDC00).to_hex
+ var hi = ((((cp - 0x10000) & 0xFFC00) >> 10) + 0xD800).to_hex
+ var out = 2
+ for i in hi do
+ buf[out] = i
+ out += 1
+ end
+ out = 8
+ for i in lo do
+ buf[out] = i
+ out += 1
+ end
+ end
+ return buf.to_s
+ end
+
private fun u8char_tos(r: NativeString, len: Int) `{
r[len] = '\0';
switch(len){
return (self >= 'a' and self <= 'z') or (self >= 'A' and self <= 'Z')
end
+ # Is `self` an hexadecimal digit ?
+ #
+ # assert 'A'.is_hexdigit
+ # assert not 'G'.is_hexdigit
+ # assert 'a'.is_hexdigit
+ # assert not 'g'.is_hexdigit
+ # assert '5'.is_hexdigit
+ fun is_hexdigit: Bool do return (self >= '0' and self <= '9') or (self >= 'A' and self <= 'F') or
+ (self >= 'a' and self <= 'f')
+
# Returns true if the char is an alpha or a numeric digit
#
# assert 'a'.is_alphanumeric
do
return self.is_numeric or self.is_alpha
end
+
+ # Returns `self` to its int value
+ #
+ # REQUIRE: `is_hexdigit`
+ fun from_hex: Int do
+ if self >= '0' and self <= '9' then return code_point - 0x30
+ if self >= 'A' and self <= 'F' then return code_point - 0x37
+ if self >= 'a' and self <= 'f' then return code_point - 0x57
+ # Happens if self is not a hexdigit
+ assert self.is_hexdigit
+ # To make flow analysis happy
+ abort
+ end
end
redef class Collection[E]
nitlanguage / nit.git / blobdiff