diff options
Diffstat (limited to 'lib/pure/unicode.nim')
| -rw-r--r-- | lib/pure/unicode.nim | 238 |
1 files changed, 209 insertions, 29 deletions
diff --git a/lib/pure/unicode.nim b/lib/pure/unicode.nim index 5d302c9dc..ac25dccef 100644 --- a/lib/pure/unicode.nim +++ b/lib/pure/unicode.nim @@ -135,45 +135,62 @@ proc runeAt*(s: string, i: Natural): Rune = ## Returns the unicode character in ``s`` at byte index ``i`` fastRuneAt(s, i, result, false) -proc toUTF8*(c: Rune): string {.rtl, extern: "nuc$1".} = - ## Converts a rune into its UTF-8 representation +template fastToUTF8Copy*(c: Rune, s: var string, pos: int, doInc = true) = + ## Copies UTF-8 representation of `c` into the preallocated string `s` + ## starting at position `pos`. If `doInc == true`, `pos` is incremented + ## by the number of bytes that have been processed. + ## + ## To be the most efficient, make sure `s` is preallocated + ## with an additional amount equal to the byte length of + ## `c`. var i = RuneImpl(c) if i <=% 127: - result = newString(1) - result[0] = chr(i) + s.setLen(pos+1) + s[pos+0] = chr(i) + when doInc: inc(pos) elif i <=% 0x07FF: - result = newString(2) - result[0] = chr((i shr 6) or 0b110_00000) - result[1] = chr((i and ones(6)) or 0b10_0000_00) + s.setLen(pos+2) + s[pos+0] = chr((i shr 6) or 0b110_00000) + s[pos+1] = chr((i and ones(6)) or 0b10_0000_00) + when doInc: inc(pos, 2) elif i <=% 0xFFFF: - result = newString(3) - result[0] = chr(i shr 12 or 0b1110_0000) - result[1] = chr(i shr 6 and ones(6) or 0b10_0000_00) - result[2] = chr(i and ones(6) or 0b10_0000_00) + s.setLen(pos+3) + s[pos+0] = chr(i shr 12 or 0b1110_0000) + s[pos+1] = chr(i shr 6 and ones(6) or 0b10_0000_00) + s[pos+2] = chr(i and ones(6) or 0b10_0000_00) + when doInc: inc(pos, 3) elif i <=% 0x001FFFFF: - result = newString(4) - result[0] = chr(i shr 18 or 0b1111_0000) - result[1] = chr(i shr 12 and ones(6) or 0b10_0000_00) - result[2] = chr(i shr 6 and ones(6) or 0b10_0000_00) - result[3] = chr(i and ones(6) or 0b10_0000_00) + s.setLen(pos+4) + s[pos+0] = chr(i shr 18 or 0b1111_0000) + s[pos+1] = chr(i shr 12 and ones(6) or 0b10_0000_00) + s[pos+2] = chr(i shr 6 and ones(6) or 0b10_0000_00) + s[pos+3] = chr(i and ones(6) or 0b10_0000_00) + when doInc: inc(pos, 4) elif i <=% 0x03FFFFFF: - result = newString(5) - result[0] = chr(i shr 24 or 0b111110_00) - result[1] = chr(i shr 18 and ones(6) or 0b10_0000_00) - result[2] = chr(i shr 12 and ones(6) or 0b10_0000_00) - result[3] = chr(i shr 6 and ones(6) or 0b10_0000_00) - result[4] = chr(i and ones(6) or 0b10_0000_00) + s.setLen(pos+5) + s[pos+0] = chr(i shr 24 or 0b111110_00) + s[pos+1] = chr(i shr 18 and ones(6) or 0b10_0000_00) + s[pos+2] = chr(i shr 12 and ones(6) or 0b10_0000_00) + s[pos+3] = chr(i shr 6 and ones(6) or 0b10_0000_00) + s[pos+4] = chr(i and ones(6) or 0b10_0000_00) + when doInc: inc(pos, 5) elif i <=% 0x7FFFFFFF: - result = newString(6) - result[0] = chr(i shr 30 or 0b1111110_0) - result[1] = chr(i shr 24 and ones(6) or 0b10_0000_00) - result[2] = chr(i shr 18 and ones(6) or 0b10_0000_00) - result[3] = chr(i shr 12 and ones(6) or 0b10_0000_00) - result[4] = chr(i shr 6 and ones(6) or 0b10_0000_00) - result[5] = chr(i and ones(6) or 0b10_0000_00) + s.setLen(pos+6) + s[pos+0] = chr(i shr 30 or 0b1111110_0) + s[pos+1] = chr(i shr 24 and ones(6) or 0b10_0000_00) + s[pos+2] = chr(i shr 18 and ones(6) or 0b10_0000_00) + s[pos+3] = chr(i shr 12 and ones(6) or 0b10_0000_00) + s[pos+4] = chr(i shr 6 and ones(6) or 0b10_0000_00) + s[pos+5] = chr(i and ones(6) or 0b10_0000_00) + when doInc: inc(pos, 6) else: discard # error, exception? +proc toUTF8*(c: Rune): string {.rtl, extern: "nuc$1".} = + ## Converts a rune into its UTF-8 representation + result = "" + fastToUTF8Copy(c, result, 0, false) + proc `$`*(rune: Rune): string = ## Converts a Rune to a string rune.toUTF8 @@ -1352,6 +1369,136 @@ proc isCombining*(c: Rune): bool {.rtl, extern: "nuc$1", procvar.} = (c >= 0x20d0 and c <= 0x20ff) or (c >= 0xfe20 and c <= 0xfe2f)) +proc swapCase*(s: string): string {.noSideEffect, procvar, + rtl, extern: "nuc$1".} = + ## Swaps the case of unicode characters in `s` + ## + ## Returns a new string such that the cases of all unicode characters + ## are swapped if possible + + var + i = 0 + lastIndex = 0 + rune: Rune + + result = newString(len(s)) + + while i < len(s): + lastIndex = i + + fastRuneAt(s, i, rune) + + if rune.isUpper(): + rune = rune.toLower() + elif rune.isLower(): + rune = rune.toUpper() + + rune.fastToUTF8Copy(result, lastIndex) + +proc translate*(s: string, replacements: proc(key: string): string): string {. + rtl, extern: "nuc$1".} = + ## Translates words in a string using the `replacements` proc to substitute + ## words inside `s` with their replacements + ## + ## `replacements` is any proc that takes a word and returns + ## a new word to fill it's place. + + # Allocate memory for the new string based on the old one. + # If the new string length is less than the old, no allocations + # will be needed. If the new string length is greater than the + # old, then maybe only one allocation is needed + result = newStringOfCap(s.len) + + var + index = 0 + lastIndex = 0 + wordStart = 0 + inWord = false + rune: Rune + + while index < len(s): + lastIndex = index + + fastRuneAt(s, index, rune) + + let whiteSpace = rune.isWhiteSpace() + + if whiteSpace and inWord: + # If we've reached the end of a word + let word = s[wordStart ..< lastIndex] + result.add(replacements(word)) + result.add($rune) + + inWord = false + elif not whiteSpace and not inWord: + # If we've hit a non space character and + # are not currently in a word, track + # the starting index of the word + inWord = true + wordStart = lastIndex + elif whiteSpace: + result.add($rune) + + if wordStart < len(s) and inWord: + # Get the trailing word at the end + let word = s[wordStart .. ^1] + result.add(replacements(word)) + +proc title*(s: string): string {.noSideEffect, procvar, + rtl, extern: "nuc$1".} = + ## Converts `s` to a unicode title. + ## + ## Returns a new string such that the first character + ## in each word inside `s` is capitalized + + var + i = 0 + lastIndex = 0 + rune: Rune + + result = newString(len(s)) + + var firstRune = true + + while i < len(s): + lastIndex = i + + fastRuneAt(s, i, rune) + + if not rune.isWhiteSpace() and firstRune: + rune = rune.toUpper() + firstRune = false + elif rune.isWhiteSpace(): + firstRune = true + + rune.fastToUTF8Copy(result, lastIndex) + +proc isTitle*(s: string): bool {.noSideEffect, procvar, + rtl, extern: "nuc$1Str".}= + ## Checks whether or not `s` is a unicode title. + ## + ## Returns true if the first character in each word inside `s` + ## are upper case and there is at least one character in `s`. + if s.len() == 0: + return false + + result = true + + var + i = 0 + rune: Rune + + var firstRune = true + + while i < len(s) and result: + fastRuneAt(s, i, rune, doInc=true) + + if not rune.isWhiteSpace() and firstRune: + result = rune.isUpper() and result + firstRune = false + elif rune.isWhiteSpace(): + firstRune = true + iterator runes*(s: string): Rune = ## Iterates over any unicode character of the string ``s`` var @@ -1451,6 +1598,39 @@ when isMainModule: compared = (someString == $someRunes) doAssert compared == true + proc test_replacements(word: string): string = + case word + of "two": + return "2" + of "foo": + return "BAR" + of "βeta": + return "beta" + of "alpha": + return "αlpha" + else: + return "12345" + + doAssert translate("two not alpha foo βeta", test_replacements) == "2 12345 αlpha BAR beta" + doAssert translate(" two not foo βeta ", test_replacements) == " 2 12345 BAR beta " + + doAssert title("foo bar") == "Foo Bar" + doAssert title("αlpha βeta γamma") == "Αlpha Βeta Γamma" + doAssert title("") == "" + + doAssert isTitle("Foo") + doAssert(not isTitle("Foo bar")) + doAssert(not isTitle("αlpha Βeta")) + doAssert(isTitle("Αlpha Βeta Γamma")) + doAssert(not isTitle("fFoo")) + + doAssert swapCase("FooBar") == "fOObAR" + doAssert swapCase(" ") == " " + doAssert swapCase("Αlpha Βeta Γamma") == "αLPHA βETA γAMMA" + doAssert swapCase("a✓B") == "A✓b" + doAssert swapCase("") == "" + + doAssert reversed("Reverse this!") == "!siht esreveR" doAssert reversed("先秦兩漢") == "漢兩秦先" doAssert reversed("as⃝df̅") == "f̅ds⃝a" |