Unicode strings

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Task
Unicode strings
You are encouraged to solve this task according to the task description, using any language you may know.

As the world gets smaller each day, internationalization becomes more and more important. For handling multiple languages, Unicode is your best friend. It is a very capable tool, but also quite complex compared to older single- and double-byte character encodings. How well prepared is your programming language for Unicode? Discuss and demonstrate its unicode awareness and capabilities. Some suggested topics:

  • How easy is it to present Unicode strings in source code? Can Unicode literals be written directly, or be part of identifiers/keywords/etc?
  • How well can the language communicate with the rest of the world? Is it good at input/output with Unicode?
  • Is it convenient to manipulate Unicode strings in the language?
  • How broad/deep does the language support Unicode? What encodings (e.g. UTF-8, UTF-16, etc) can be used? Normalization?

Note This task is a bit unusual in that it encourages general discussion rather than clever coding.

See also:

Contents

[edit] 80386 Assembly

  • How well prepared is the programming language for Unicode? - Prepared, in terms of handling: Assembly language can do anything the computer can do. However, it has no Unicode facilities as part of the language.
  • How easy is it to present Unicode strings in source code? - Easy, they are in hexadecimal.
  • Can Unicode literals be written directly - Depends on the compiler. MASM does not allow this. All data in assembly language is created from a series of bytes. Literal characters are not part of the language. They are number crunched down into a byte sequence by the compiler. If the compiler can read Unicode, then you are onto a winner.
  • or be part of identifiers/keywords/etc? - Depends on compiler. Intel notation does not use Unicode identifiers or mnemonics. Assembly language converts to numeric machine code, so everything is represented as mnemonics. You can use your own mnemonics, but you need to be able to compile them. One way to do this is to use a wrapper (which you would create) that converts your Unicode mnemonic notation to the notation that the compiler is expecting.
  • How well can the language communicate with the rest of the world? - Difficult. This is a low level language, so all communication can be done, but you have to set up data structures, and produce many lines of code for just basic tasks.
  • Is it good at input/output with Unicode? - Yes and No. The Unicode bit is easy, but for input/output, we have to set up data structures and produce many lines of code, or link to code libraries.
  • Is it convenient to manipulate Unicode strings in the language? - No. String manipulation requires lots of code. We can link to code libraries though, but it is not as straightforward, as it would be in a higher level language.
  • How broad/deep does the language support Unicode? We can do anything in assembly language, so support is 100%, but nothing is convenient with respect to Unicode. Strings are just a series of bytes, treatment of a series of bytes as a string is down to the compiler, if it provides string support as an extension. You need to be prepared to define data structures containing the values that you want.
  • What encodings (e.g. UTF-8, UTF-16, etc) can be used? All encodings are supported, but again, nothing is convenient with respect to encodings, although hexadecimal notation is good to use in assembly language. Normalization is not supported unless you write lots of code.

[edit] Ada

  • As of Ada 2005, all source/identifiers/keywords/literals/etc can be in up to 32bit characters as long as the compiler is told what encoding you are using.
  • Unicode input/output has been in ada for much longer, only unicode source/literals are recent additions to the standard.
  • Manipulation is the same as any other strings, but operates from *_Wide_Text_* modules rather than *_Text_*
  • Supports the entire set of characters from ISO/IEC 10646:2003
  • Extensive support of Unicode (including normalization, collation, etc.) and text codecs are provided by Matreshka.

[edit] ALGOL 68

How well prepared is the programming language for Unicode? - ALGOL 68 is character set agnostic and the standard explicitly permits the use of a universal character set. The standard includes routines like "make conv" to permit the opening of files and devices using alternate characters sets and converting character sets on the fly.

How easy is it to present Unicode strings in source code? - Easy.

Can Unicode literals be written directly - No, a REPR operator must be used to encode the string in UTF8.

Can Unicode literals be part of identifiers/keywords/etc? - Yes... ALGOL 68 is character set agnostic and the standard explicitly permits the use of a universal character set. Implementation for English, German, Polish and Cyrillic have been created. However ALGOL 68G supports only "Worthy" Character sets.

How well can the language communicate with the rest of the world? - Acceptable.

Is it good at input/output with Unicode? - No, although the "make conv" routine is in the standard it is rarely fully implemented.

Is it convenient to manipulate Unicode strings in the language? - Yes

How broad/deep does the language support Unicode? What encodings (e.g. UTF-8, UTF-16, etc) can be used? The attached set of utility routine is currently only for UTF8. Currently the Unicode routines like is_digit, is_letter, is_lower_case etc are not implemented.

Works with: ALGOL 68 version Revision 1 - no extensions to language used.
Works with: ALGOL 68G version Any - tested with release 1.18.0-9h.tiny.
#!/usr/local/bin/a68g --script #
# -*- coding: utf-8 -*- #
 
# UNICHAR/UNICODE must be printed using REPR to convert to UTF8 #
 
MODE UNICHAR = STRUCT(BITS #31# bits); # assuming bits width >=31 #
MODE UNICODE = FLEX[0]UNICHAR;
 
OP INITUNICHAR = (BITS bits)UNICHAR: (UNICHAR out; bits OF out := #ABS# bits; out);
OP INITUNICHAR = (CHAR char)UNICHAR: (UNICHAR out; bits OF out := BIN ABS char; out);
OP INITBITS = (UNICHAR unichar)BITS: #BIN# bits OF unichar;
 
PROC raise value error = ([]UNION(FORMAT,BITS,STRING)argv )VOID: (
putf(stand error, argv); stop
);
 
MODE YIELDCHAR = PROC(CHAR)VOID; MODE GENCHAR = PROC(YIELDCHAR)VOID;
MODE YIELDUNICHAR = PROC(UNICHAR)VOID; MODE GENUNICHAR = PROC(YIELDUNICHAR)VOID;
 
PRIO DOCONV = 1;
 
# Convert a stream of UNICHAR into a stream of UTFCHAR #
OP DOCONV = (GENUNICHAR gen unichar, YIELDCHAR yield)VOID:(
BITS non ascii = NOT 2r1111111;
# FOR UNICHAR unichar IN # gen unichar( # ) DO ( #
## (UNICHAR unichar)VOID: (
BITS bits := INITBITS unichar;
IF (bits AND non ascii) = 2r0 THEN # ascii #
yield(REPR ABS bits)
ELSE
FLEX[6]CHAR buf := "?"*6; # initialise work around #
INT bytes := 0;
BITS byte lead bits = 2r10000000;
FOR ofs FROM UPB buf BY -1 WHILE
bytes +:= 1;
buf[ofs]:= REPR ABS (byte lead bits OR bits AND 2r111111);
bits := bits SHR 6;
# WHILE # bits NE 2r0 DO
SKIP
OD;
BITS first byte lead bits = BIN (ABS(2r1 SHL bytes)-2) SHL (UPB buf - bytes + 1);
buf := buf[UPB buf-bytes+1:];
buf[1] := REPR ABS(BIN ABS buf[1] OR first byte lead bits);
FOR i TO UPB buf DO yield(buf[i]) OD
FI
# OD # ))
);
 
# Convert a STRING into a stream of UNICHAR #
OP DOCONV = (STRING string, YIELDUNICHAR yield)VOID: (
PROC gen char = (YIELDCHAR yield)VOID:
FOR i FROM LWB string TO UPB string DO yield(string[i]) OD;
gen char DOCONV yield
);
 
CO Prosser/Thompson UTF8 encoding scheme
Bits Last code point Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6
7 U+007F 0xxxxxxx
11 U+07FF 110xxxxx 10xxxxxx
16 U+FFFF 1110xxxx 10xxxxxx 10xxxxxx
21 U+1FFFFF 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
26 U+3FFFFFF 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx
31 U+7FFFFFFF 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx
END CO
 
# Quickly calculate the length of the UTF8 encoded string #
PROC upb utf8 = (STRING utf8 string)INT:(
INT bytes to go := 0;
INT upb := 0;
FOR i FROM LWB utf8 string TO UPB utf8 string DO
CHAR byte := utf8 string[i];
IF bytes to go = 0 THEN # start new utf char #
bytes to go :=
IF ABS byte <= ABS 2r01111111 THEN 1 # 7 bits #
ELIF ABS byte <= ABS 2r11011111 THEN 2 # 11 bits #
ELIF ABS byte <= ABS 2r11101111 THEN 3 # 16 bits #
ELIF ABS byte <= ABS 2r11110111 THEN 4 # 21 bits #
ELIF ABS byte <= ABS 2r11111011 THEN 5 # 26 bits #
ELIF ABS byte <= ABS 2r11111101 THEN 6 # 31 bits #
ELSE raise value error(("Invalid UTF-8 bytes", BIN ABS byte)); ~ FI
FI;
bytes to go -:= 1; # skip over trailing bytes #
IF bytes to go = 0 THEN upb +:= 1 FI
OD;
upb
);
 
# Convert a stream of CHAR into a stream of UNICHAR #
OP DOCONV = (GENCHAR gen char, YIELDUNICHAR yield)VOID: (
INT bytes to go := 0;
INT lshift;
BITS mask, out;
 
# FOR CHAR byte IN # gen char( # ) DO ( #
## (CHAR byte)VOID: (
INT bits := ABS byte;
IF bytes to go = 0 THEN # start new unichar #
bytes to go :=
IF bits <= ABS 2r01111111 THEN 1 # 7 bits #
ELIF bits <= ABS 2r11011111 THEN 2 # 11 bits #
ELIF bits <= ABS 2r11101111 THEN 3 # 16 bits #
ELIF bits <= ABS 2r11110111 THEN 4 # 21 bits #
ELIF bits <= ABS 2r11111011 THEN 5 # 26 bits #
ELIF bits <= ABS 2r11111101 THEN 6 # 31 bits #
ELSE raise value error(("Invalid UTF-8 bytes", BIN bits)); ~ FI;
IF bytes to go = 1 THEN
lshift := 7; mask := 2r1111111
ELSE
lshift := 7 - bytes to go; mask := BIN(ABS(2r1 SHL lshift)-1)
FI;
out := mask AND BIN bits;
 
lshift := 6; mask := 2r111111 # subsequently pic 6 bits at a time #
ELSE
out := (out SHL lshift) OR ( mask AND BIN bits)
FI;
bytes to go -:= 1;
IF bytes to go = 0 THEN yield(INITUNICHAR out) FI
# OD # ))
);
 
# Convert a string of UNICHAR into a stream of UTFCHAR #
OP DOCONV = (UNICODE unicode, YIELDCHAR yield)VOID:(
PROC gen unichar = (YIELDUNICHAR yield)VOID:
FOR i FROM LWB unicode TO UPB unicode DO yield(unicode[i]) OD;
gen unichar DOCONV yield
);
 
# Some convenience/shorthand U operators #
# Convert a BITS into a UNICODE char #
OP U = (BITS bits)UNICHAR:
INITUNICHAR bits;
 
# Convert a []BITS into a UNICODE char #
OP U = ([]BITS array bits)[]UNICHAR:(
[LWB array bits:UPB array bits]UNICHAR out;
FOR i FROM LWB array bits TO UPB array bits DO bits OF out[i]:=array bits[i] OD;
out
);
 
# Convert a CHAR into a UNICODE char #
OP U = (CHAR char)UNICHAR:
INITUNICHAR char;
 
# Convert a STRING into a UNICODE string #
OP U = (STRING utf8 string)UNICODE: (
FLEX[upb utf8(utf8 string)]UNICHAR out;
INT i := 0;
# FOR UNICHAR char IN # utf8 string DOCONV (
## (UNICHAR char)VOID:
out[i+:=1] := char
# OD #);
out
);
 
# Convert a UNICODE string into a UTF8 STRING #
OP REPR = (UNICODE string)STRING: (
STRING out;
# FOR CHAR char IN # string DOCONV (
## (CHAR char)VOID: (
out +:= char
# OD #));
out
);
 
# define the most useful OPerators on UNICODE CHARacter arrays #
# Note: LWB, UPB and slicing works as per normal #
 
OP + = (UNICODE a,b)UNICODE: (
[UPB a + UPB b]UNICHAR out;
out[:UPB a]:= a; out[UPB a+1:]:= b;
out
);
 
OP + = (UNICODE a, UNICHAR b)UNICODE: a+UNICODE(b);
OP + = (UNICHAR a, UNICODE b)UNICODE: UNICODE(a)+b;
OP + = (UNICHAR a,b)UNICODE: UNICODE(a)+b;
 
# Suffix a character to the end of a UNICODE string #
OP +:= = (REF UNICODE a, UNICODE b)VOID: a := a + b;
OP +:= = (REF UNICODE a, UNICHAR b)VOID: a := a + b;
 
# Prefix a character to the beginning of a UNICODE string #
OP +=: = (UNICODE b, REF UNICODE a)VOID: a := b + a;
OP +=: = (UNICHAR b, REF UNICODE a)VOID: a := b + a;
 
OP * = (UNICODE a, INT n)UNICODE: (
UNICODE out := a;
FOR i FROM 2 TO n DO out +:= a OD;
out
);
OP * = (INT n, UNICODE a)UNICODE: a * n;
 
OP * = (UNICHAR a, INT n)UNICODE: UNICODE(a)*n;
OP * = (INT n, UNICHAR a)UNICODE: n*UNICODE(a);
 
OP *:= = (REF UNICODE a, INT b)VOID: a := a * b;
 
# Wirthy Operators #
OP LT = (UNICHAR a,b)BOOL: ABS bits OF a LT ABS bits OF b,
LE = (UNICHAR a,b)BOOL: ABS bits OF a LE ABS bits OF b,
EQ = (UNICHAR a,b)BOOL: ABS bits OF a EQ ABS bits OF b,
NE = (UNICHAR a,b)BOOL: ABS bits OF a NE ABS bits OF b,
GE = (UNICHAR a,b)BOOL: ABS bits OF a GE ABS bits OF b,
GT = (UNICHAR a,b)BOOL: ABS bits OF a GT ABS bits OF b;
 
# ASCII OPerators #
OP < = (UNICHAR a,b)BOOL: a LT b,
<= = (UNICHAR a,b)BOOL: a LE b,
= = (UNICHAR a,b)BOOL: a EQ b,
/= = (UNICHAR a,b)BOOL: a NE b,
>= = (UNICHAR a,b)BOOL: a GE b,
> = (UNICHAR a,b)BOOL: a GT b;
 
# Non ASCII OPerators
OP ≤ = (UNICHAR a,b)BOOL: a LE b,
≠ = (UNICHAR a,b)BOOL: a NE b,
≥ = (UNICHAR a,b)BOOL: a GE b;
#

 
# Compare two UNICODE strings for equality #
PROC unicode cmp = (UNICODE str a,str b)INT: (
 
IF LWB str a > LWB str b THEN exit lt ELIF LWB str a < LWB str b THEN exit gt FI;
 
INT min upb = UPB(UPB str a < UPB str b | str a | str b );
 
FOR i FROM LWB str a TO min upb DO
UNICHAR a := str a[i], UNICHAR b := str b[i];
IF a < b THEN exit lt ELIF a > b THEN exit gt FI
OD;
 
IF UPB str a > UPB str b THEN exit gt ELIF UPB str a < UPB str b THEN exit lt FI;
 
exit eq: 0 EXIT
exit lt: -1 EXIT
exit gt: 1
);
 
OP LT = (UNICODE a,b)BOOL: unicode cmp(a,b)< 0,
LE = (UNICODE a,b)BOOL: unicode cmp(a,b)<=0,
EQ = (UNICODE a,b)BOOL: unicode cmp(a,b) =0,
NE = (UNICODE a,b)BOOL: unicode cmp(a,b)/=0,
GE = (UNICODE a,b)BOOL: unicode cmp(a,b)>=0,
GT = (UNICODE a,b)BOOL: unicode cmp(a,b)> 0;
 
# ASCII OPerators #
OP < = (UNICODE a,b)BOOL: a LT b,
<= = (UNICODE a,b)BOOL: a LE b,
= = (UNICODE a,b)BOOL: a EQ b,
/= = (UNICODE a,b)BOOL: a NE b,
>= = (UNICODE a,b)BOOL: a GE b,
> = (UNICODE a,b)BOOL: a GT b;
 
# Non ASCII OPerators
OP ≤ = (UNICODE a,b)BOOL: a LE b,
≠ = (UNICODE a,b)BOOL: a NE b,
≥ = (UNICODE a,b)BOOL: a GE b;
#

 
COMMENT - Todo: for all UNICODE and UNICHAR
Add NonASCII OPerators: ×, ×:=,
Add ASCII Operators: &, &:=, &=:
Add Wirthy OPerators: PLUSTO, PLUSAB, TIMESAB for UNICODE/UNICHAR,
Add UNICODE against UNICHAR comparison OPerators,
Add char_in_string and string_in_string PROCedures,
Add standard Unicode functions:
to_upper_case, to_lower_case, unicode_block, char_count,
get_directionality, get_numeric_value, get_type, is_defined,
is_digit, is_identifier_ignorable, is_iso_control,
is_letter, is_letter_or_digit, is_lower_case, is_mirrored,
is_space_char, is_supplementary_code_point, is_title_case,
is_unicode_identifier_part, is_unicode_identifier_start,
is_upper_case, is_valid_code_point, is_whitespace
END COMMENT
 
test:(
 
UNICHAR aircraft := U16r 2708;
printf(($"aircraft: "$, $"16r"16rdddd$, UNICODE(aircraft), $g$, " => ", REPR UNICODE(aircraft), $l$));
 
UNICODE chinese forty two = U16r 56db + U16r 5341 + U16r 4e8c;
printf(($"chinese forty two: "$, $g$, REPR chinese forty two, ", length string = ", UPB chinese forty two, $l$));
 
UNICODE poker = U "A123456789♥♦♣♠JQK";
printf(($"poker: "$, $g$, REPR poker, ", length string = ", UPB poker, $l$));
 
UNICODE selectric := U"×÷≤≥≠¬∨∧⏨→↓↑□⌊⌈⎩⎧○⊥¢";
printf(($"selectric: "$, $g$, REPR selectric, $l$));
printf(($"selectric*4: "$, $g$, REPR(selectric*4), $l$));
 
print((
"1 < 2 is ", U"1" < U"2", ", ",
"111 < 11 is ",U"111" < U"11", ", ",
"111 < 12 is ",U"111" < U"12", ", ",
"♥ < ♦ is ", U"♥" < U"♦", ", ",
"♥Q < ♥K is ",U"♥Q" < U"♥K", " & ",
"♥J < ♥K is ",U"♥J" < U"♥K", new line
))
 
)

Output:

aircraft: 16r2708 => ✈
chinese forty two: 四十二, length string =          +3
poker: A123456789♥♦♣♠JQK, length string =         +17
selectric: ×÷≤≥≠¬∨∧⏨→↓↑□⌊⌈⎩⎧○⊥¢
selectric*4: ×÷≤≥≠¬∨∧⏨→↓↑□⌊⌈⎩⎧○⊥¢×÷≤≥≠¬∨∧⏨→↓↑□⌊⌈⎩⎧○⊥¢×÷≤≥≠¬∨∧⏨→↓↑□⌊⌈⎩⎧○⊥¢×÷≤≥≠¬∨∧⏨→↓↑□⌊⌈⎩⎧○⊥¢
1 < 2 is T, 111 < 11 is F, 111 < 12 is T, ♥ < ♦ is T, ♥Q < ♥K is F & ♥J < ♥K is T

[edit] AutoHotkey

How easy is it to present Unicode strings in source code? - Simple, as long as the script is saved as Unicode and you're using a Unicode build

Can Unicode literals be written directly, or be part of identifiers/keywords/etc? - Yes, see above

How well can the language communicate with the rest of the world? Is it good at input/output with Unicode? - it can create GUI's and send Unicode characters.

Is it convenient to manipulate Unicode strings in the language? - Yes: they act like any other string, apart from lowlevel functions such as NumPut which deal with bytes.

How broad/deep does the language support Unicode? What encodings (e.g. UTF-8, UTF-16, etc) can be used? UTF-8 is most often used. StrPut/StrGet and FileRead/FileAppend allow unicode in AutoHotkey_L (the current build)

[edit] AWK

How well prepared is the programming language for Unicode? - Not really prepared. AWK is a tool for manipulating ASCII input.

How easy is it to present Unicode strings in source code? - Easy. They can be represented in hexadecimal.

Can Unicode literals be written directly - No

or be part of identifiers/keywords/etc? - No

How well can the language communicate with the rest of the world? - The language is not good at communications, but can utilize external tools.

Is it good at input/output with Unicode? - No

Is it convenient to manipulate Unicode strings in the language? - No

How broad/deep does the language support Unicode? What encodings (e.g. UTF-8, UTF-16, etc) can be used? There is no inbuilt support for Unicode, but all encodings can be represented through hexadecimal strings.

[edit] BBC BASIC

  • How easy is it to present Unicode strings in source code?

As of version 5.94a, the BBC BASIC for Windows source code editor supports Unicode text in string literals and comments (remarks). This includes bi-directional text and Arabic ligatures.

  • Can Unicode literals be written directly?

If a suitable keyboard and/or Input Method Editor is available Unicode text may be entered directly into the editor.

  • or be part of identifiers/keywords/etc?

Identifiers (variable names) and keywords cannot use Unicode characters.

  • How well can the language communicate with the rest of the world? Is it good at input/output with Unicode?

Output of Unicode text to both the screen and the printer is supported, but must be enabled using a VDU 23,22 command since the default output mode is ANSI. The text printing direction can be set to right-to-left for languages such as Hebrew and Arabic. Run-time support for Arabic ligatures is not built-in, but is provided by means of the FNarabic() function. No specific support for Unicode input at run time is provided, although this is possible by means of Windows controls.

  • Is it convenient to manipulate Unicode strings in the language?

The supported character encoding is UTF-8 which, being a byte stream, is compatible with most of the language's string manipulation functions. However, the parameters in functions like LEFT$ and MID$ refer to byte counts rather than character counts.

Code example: (whether this listing displays correctly will depend on your browser)

      VDU 23,22,640;512;8,16,16,128+8 : REM Select UTF-8 mode
*FONT Times New Roman, 20
 
PRINT "Arabic:"
 
arabic1$ = "هنا مثال يمكنك من الكتابة من اليمين"
arabic2$ = "الى اليسار باللغة العربية"
 
VDU 23,16,2;0;0;0;13 : REM Select right-to-left printing
PRINT FNarabic(arabic1$) ' FNarabic(arabic2$)
VDU 23,16,0;0;0;0;13 : REM Select left-to-right printing
 
PRINT '"Hebrew:"
 
hebrew$ = "זוהי הדגמה של כתיבת טקסט בעברית מימין לשמאל"
 
VDU 23,16,2;0;0;0;13 : REM Select right-to-left printing
PRINT hebrew$
VDU 23,16,0;0;0;0;13 : REM Select left-to-right printing
 
END
 
REM!Eject
DEF FNarabic(A$)
LOCAL A%, B%, L%, O%, P%, U%, B$
A$ += CHR$0
FOR A% = !^A$ TO !^A$+LENA$-1
IF ?A%<&80 OR ?A%>=&C0 THEN
L% = O% : O% = P% : P% = U%
U% = ((?A% AND &3F) << 6) + (A%?1 AND &3F)
IF ?A%<&80 U% = 0
CASE TRUE OF
WHEN U%=&60C OR U%=&61F: U% = 0
WHEN U%<&622:
WHEN U%<&626: U% = &01+2*(U%-&622)
WHEN U%<&628: U% = &09+4*(U%-&626)
WHEN U%<&62A: U% = &0F+4*(U%-&628)
WHEN U%<&62F: U% = &15+4*(U%-&62A)
WHEN U%<&633: U% = &29+2*(U%-&62F)
WHEN U%<&63B: U% = &31+4*(U%-&633)
WHEN U%<&641:
WHEN U%<&648: U% = &51+4*(U%-&641)
WHEN U%<&64B: U% = &6D+2*(U%-&648)
ENDCASE
IF P% IF P%<&80 THEN
B% = P%
IF O%=&5D IF P%<&5 B% += &74
IF O%=&5D IF P%=&7 B% += &72
IF O%=&5D IF P%=&D B% += &6E
IF B%>P% B$=LEFT$(B$,LENB$-3) : O% = L%
IF U% IF P%>7 IF P%<>&D IF P%<>&13 IF P%<>&29 IF P%<>&2B IF P%<>&2D IF P%<>&2F IF P%<>&6D IF P%<>&6F B% += 2
IF O% IF O%>7 IF O%<>&D IF O%<>&13 IF O%<>&29 IF O%<>&2B IF O%<>&2D IF O%<>&2F IF O%<>&6D IF O%<>&6F B% += 1
B$ = LEFT$(LEFT$(B$))+CHR$&EF+CHR$(&BA+(B%>>6))+CHR$(&80+(B%AND&3F))
ENDIF
ENDIF
B$ += CHR$?A%
NEXT
= LEFT$(B$)

Unicode bbc.gif

[edit] Bracmat

  • How easy is it to present Unicode strings in source code? Can Unicode literals be written directly, or be part of identifiers/keywords/etc?

The few keywords Bracmat knows are all ASCII. Identifiers and values can consist of all non-zero bytes, so UTF-8 encoded strings are allowed.

  • How well can the language communicate with the rest of the world? Is it good at input/output with Unicode?

Input and output of UTF-8 encoded data and source code is easy. No special measures have to be taken. On reading HTML and JSON, hexcodes and HTML entities are converted to their UTF-8 equivalents.

  • Is it convenient to manipulate Unicode strings in the language?

Yes, apart from counting characters, as UTF-8 has varying width. When converting a string to lower or uppercase, UTF-8 is assumed. If a string is not valid UTF-8, ISO-8859-1 (Latin-1) is assumed.

  • How broad/deep does the language support Unicode? What encodings (e.g. UTF-8, UTF-16, etc) can be used?

Most UTF-16 and UTF-32 strings contain null bytes in non-final positions and can therefore not be handled easily.

[edit] C

C is not the most unicode friendly language, to put it mildly. Generally using unicode in C requires dealing with locales, manage data types carefully, and checking various aspects of your compiler. Directly embedding unicode strings in your C source might be a bad idea, too; it's safer to use their hex values. Here's a short example of doing the simplest string handling: print it.
#include <stdio.h>
#include <stdlib.h>
#include <locale.h>
 
/* wchar_t is the standard type for wide chars; what it is internally
* depends on the compiler.
*/

wchar_t poker[] = L"♥♦♣♠";
wchar_t four_two[] = L"\x56db\x5341\x4e8c";
 
int main() {
/* Set the locale to alert C's multibyte output routines */
if (!setlocale(LC_CTYPE, "")) {
fprintf(stderr, "Locale failure, check your env vars\n");
return 1;
}
 
#ifdef __STDC_ISO_10646__
/* C99 compilers should understand these */
printf("%lc\n", 0x2708); /* ✈ */
printf("%ls\n", poker); /* ♥♦♣♠ */
printf("%ls\n", four_two); /* 四十二 */
#else
/* oh well */
printf("airplane\n");
printf("club diamond club spade\n");
printf("for ty two\n");
#endif
return 0;
}

[edit] DWScript

Source code is expected in Unicode (typically UTF-8 or UTF-16), characters above 127 (non-ASCII) are not part of the language, and are accepted literally as string characters or as identifier characters.

Characters in a string can also by specified explicitly by specifying the Unicode codepoint with a # followed by a decimal number, or a #$ followed by an hexadecimal codepoint (if the codepoint is outside the BMP, it'll result in two UTF-16 words). Contrarily to some other Pascal variants (like Delphi), explicit character codes are always and consistently interpreted as Unicode codepoints.

Strings are UTF-16.

[edit] Elixir

Elixir has exceptionally good Unicode support in Strings. Its String module is fully compliant with the Unicode Standard, version 6.3.0. Internally, Strings are encoded in UTF-8. As source files are also typically Unicode encoded, String literals can be either written directly or via escape sequences. However, non-ASCII Unicode identifiers (variables, functions, ...) are not allowed.

[edit] Erlang

The simplified explanation is that Erlang allows Unicode in comments/data/file names/etc, but not in function or variable names.

[edit] Go

Go source code is specified to be UTF-8 encoded. This directly allows any Unicode code point in character and string literals. Unicode is also allowed in identifiers like variables and field names, with some restrictions. The string data type represents a read-only sequence of bytes, conventionally but not necessarily represents UTF-8-encoded text. A number of built-in features interpret strings as UTF-8. For example,

    var i int
var u rune
for i, u = range "voilà" {
fmt.Println(i, u)
}

outputs

0 118
1 111
2 105
3 108
4 224

224 being the Unicode code point for the à character. Note rune is predefined to be a type that can hold a Unicode code point.

In contrast,

    w := "voilà"
for i := 0; i < len(w); i++ {
fmt.Println(i, w[i])
}
 

outputs

0 118
1 111
2 105
3 108
4 195
5 160

bytes 4 and 5 showing the UTF-8 encoding of à. The expression w[i] in this case has the type of byte rather than rune. A Go blog post covers this in more detail: Strings, bytes, runes and characters in Go.

The heavily used standard packages bytes and strings both have functions for working with strings both as UTF-8 and as encoding-unspecified bytes. The standard packages unicode, unicode/utf8, and unicode/utf16 have additional functions.

Normalization support is available in the sub-repository package code.google.com/p/go.text/unicode/norm. It contains a number of string manipulation functions that work with the four normalization forms NFC, NFD, NFKC, and NFKD. The normalization form type in this package implements the io.Reader and io.WriteCloser interfaces to enable on-the-fly normalization during I/O. A Go blog post covers this in more detail: Text normalization in Go.

There is no built-in or automatic handling of byte order marks (which are at best unnecessary with UTF-8).

[edit] Haskell

Unicode is built-in in Haskell, so it can be used in strings and functions names.


[edit] J

Unicode characters can be represented directly in J strings:

   '♥♦♣♠'
♥♦♣♠

By default, they are represented as utf-8:

   #'♥♦♣♠'
12

The above string requires 12 literal elements to represent the four characters using utf-8.

However, they can be represented as utf-16 instead:

  7 u:'♥♦♣♠'
♥♦♣♠
#7 u:'♥♦♣♠'
4

The above string requires 4 literal elements to represent the four characters using utf-16. (7 u: string produces a utf-16 result.)

These forms are not treated as equivalent:

   '♥♦♣♠' -: 7 u:'♥♦♣♠'
0

The utf-8 string of literals is a different string of literals from the utf-16 string.

unless the character literals themselves are equivalent:

   'abcd'-:7 u:'abcd'
1

Here, we were dealing with ascii characters, so the four literals needed to represent the characters using utf-8 matched the four literals needed to represent the characters using utf-16.

When this is likely to be an issue, you should enforce a single representation. For example:

   '♥♦♣♠' -:&(7&u:) 7 u:'♥♦♣♠'
1
'♥♦♣♠' -:&(8&u:) 7 u:'♥♦♣♠'
1

Here, we see that even when comparing non-ascii characters, we can coerce both arguments to be utf-8 or utf-16 and in either case the resulting literal strings match. (8 u: string produces a utf-8 result.)

Output uses characters in whatever format they happen to be in. Character input assumes 8 bit characters but places no additional interpretation on them.

See also: http://www.jsoftware.com/help/dictionary/duco.htm

Non-ascii unicode characters are not legal tokens or names, within current versions J.

[edit] Java

How easy is it to present Unicode strings in source code?

Very easy. It is not specified what encoding the source code must be in, as long as it can be interpreted into a stream of UTF-16 characters. Most compilers probably take UTF-8.

In any case, even using only ASCII characters, any UTF-16 character can be embedded into the source code by using a Unicode escape \uxxxx (where xxxx is the hex code of the character), which is processed before any other steps by the compiler. This means that it is possible to write an entire program out of Unicode escapes. This also means that a Unicode escape could mess up the language syntax, if it happens to be the escape of a whitespace or quote character (please don't do that).

Can Unicode literals be written directly, or be part of identifiers/keywords/etc?

UTF-16 characters can be written directly in character and string literals and comments (there is no difference between "directly" and using Unicode escapes, since they are processed at the first step). UTF-16 characters can be part of identifiers (either directly or through a Unicode escape).

How well can the language communicate with the rest of the world? Is it good at input/output with Unicode?

Yes

Is it convenient to manipulate Unicode strings in the language?

The String class in Java is basically a sequence of char elements, representing the string encoded in UTF-16. char is a 16-bit type, and thus one char does not necessarily correspond to one Unicode character, since supplementary characters can have code points greater than U+FFFF. However, if your string only consists of characters from the Basic Multilingual Plane (which is most of the time), then one char does correspond to one Unicode character.

Starting in J2SE 5 (1.5), Java has fairly convenient methods for dealing with true Unicode characters, even supplementary ones. Many methods that deal with characters have versions for both char and int. For example, String has the codePointAt method, analogous to the charAt method.

How broad/deep does the language support Unicode? What encodings (e.g. UTF-8, UTF-16, etc) can be used? Normalization?

[edit] jq

jq's data types are JSON's data types. In particular, jq strings are UTF-8 strings. See json.org for further details.

jq identifiers, however, are restricted to a subset of ASCII.

The jq command does have several options in support of flexibility when "communicating with the world":

 --raw-input    | -R :: each line of input is converted to a JSON string;
 --ascii-output | -a :: every non-ASCII character that would otherwise
                        be sent to output is translated to an equivalent
                        ASCII escape sequence;
 --raw-output   | -r :: output strings as raw strings, e.g. "a\nb" is
                        output as:
a
b

[edit] Julia

Non-ASCII strings in Julia are UTF8-encoded by default, and Unicode identifiers are also supported:

julia> 四十二 = "voilà";
julia> println(四十二)
voilà

And you can also specify unicode characters by ordinal:

julia>println("\u2708")

[edit] Lasso

All string data in Lasso is processed as double-byte Unicode characters. Any input is assumed to be UTF-8 if not otherwise told. All output is UTF-8 unless specified to a different encoding. You can specify unicode characters by ordinal.

Variable names can not contain anything but ASCII.

local(unicode = '♥♦♣♠')
#unicode -> append('\u9830')
#unicode
'<br />'
#unicode -> get (2)
'<br />'
#unicode -> get (4) -> integer

Output:

♥♦♣♠頰
♦
9824

[edit] Locomotive Basic

The Amstrad CPC464 does not have native Unicode support. It is possible to represent Unicode by using ASCII based hexadecimal number sequences, or by using a form of escape sequence encoding, such as \uXXXX. However, there is only 48k of memory available and 510k would be needed to store the Unicode characters for display, so Unicode is not really viable on this platform.

  • How well prepared is the programming language for Unicode? - Not good. There are no Unicode symbols in the ROM.
  • How easy is it to present Unicode strings in source code? - Easy, they are in hexadecimal.
  • Can Unicode literals be written directly - No
  • or be part of identifiers/keywords/etc? - No
  • How well can the language communicate with the rest of the world? - Not good. There is no TCP/IP stack, and the computer does not have an Ethernet port.
  • Is it good at input/output with Unicode? - Not good. There are no Unicode symbols in ROM, or on the keyboard.
  • Is it convenient to manipulate Unicode strings in the language? - Moderate. The language is not designed for Unicode, so has no inbuilt Unicode functions. However, it is possible to write manipulation routines, and the language is good at arithmetic, so no problem.
  • How broad/deep does the language support Unicode? What encodings (e.g. UTF-8, UTF-16, etc) can be used? There is no inbuilt support for Unicode, but all encodings can be represented through hexadecimal strings.

It should be added however that the character set can be easily redefined from BASIC with the SYMBOL and SYMBOL AFTER commands, so the CPC character set can be turned into e.g. Latin-1. As two-byte UTF-8 characters can be converted to Latin-1, at least a subset of Unicode can be printed in this way:

10 CLS:DEFINT a-z
20 ' define German umlauts as in Latin-1
30 SYMBOL AFTER 196
40 SYMBOL 196,&66,&18,&3C,&66,&7E,&66,&66,&0
50 SYMBOL 214,&C6,&0,&7C,&C6,&C6,&C6,&7C,&0
60 SYMBOL 220,&66,&0,&66,&66,&66,&66,&3C,&0
70 SYMBOL 228,&6C,&0,&78,&C,&7C,&CC,&76,&0
80 SYMBOL 246,&66,&0,&0,&3C,&66,&66,&3C,&0
90 SYMBOL 252,&66,&0,&0,&66,&66,&66,&3E,&0
100 SYMBOL 223,&38,&6C,&6C,&78,&6C,&78,&60,&0
110 ' print string
120 READ h
130 IF h=0 THEN 180
140 IF (h AND &X11100000)=&X11000000 THEN uc=(h AND &X11111)*2^6:GOTO 120
150 IF (h AND &X11000000)=&X10000000 THEN uc=uc+(h AND &X111111):h=uc
160 PRINT CHR$(h);
170 GOTO 120
180 PRINT
190 END
200 ' zero-terminated UTF-8 string
210 DATA &48,&C3,&A4,&6C,&6C,&C3,&B6,&20,&4C,&C3,&BC,&64,&77,&69,&67,&2E,&20,&C3,&84,&C3,&96,&C3,&9C
220 DATA &20,&C3,&A4,&C3,&B6,&C3,&BC,&20,&56,&69,&65,&6C,&65,&20,&47,&72,&C3,&BC,&C3,&9F,&65,&21,&00

Produces this (slightly nonsensical) output:

Unicode print locomotive basic.png

[edit] Mathematica

Mathematica supports full Unicode throughout -- in strings, symbols, graphics and external operations -- allowing immediate streamlined use of all standard international character sets, integrated with native text entry. The global variable $CharacterEncodings is an option for input and output functions which specifies what raw character encoding should be used.

{"AdobeStandard", "ASCII", "CP936", "CP949", "CP950", "Custom", 
"EUC-JP", "EUC", "IBM-850", "ISO10646-1", "ISO8859-15", "ISO8859-1", 
"ISO8859-2", "ISO8859-3", "ISO8859-4", "ISO8859-5", "ISO8859-6", 
"ISO8859-7", "ISO8859-8", "ISO8859-9", "ISOLatin1", "ISOLatin2", 
"ISOLatin3", "ISOLatin4", "ISOLatinCyrillic", "Klingon", "KOI8-R", 
"MacintoshArabic", "MacintoshChineseSimplified", 
"MacintoshChineseTraditional", "MacintoshCroatian", 
"MacintoshCyrillic", "MacintoshGreek", "MacintoshHebrew", 
"MacintoshIcelandic", "MacintoshKorean", 
"MacintoshNonCyrillicSlavic", "MacintoshRomanian", "MacintoshRoman", 
"MacintoshThai", "MacintoshTurkish", "MacintoshUkrainian", "Math1", 
"Math2", "Math3", "Math4", "Math5", "Mathematica1", "Mathematica2",
"Mathematica3", "Mathematica4", "Mathematica5", "Mathematica6", 
"Mathematica7", "PrintableASCII", "ShiftJIS", "Symbol", "Unicode", 
"UTF8", "WindowsANSI", "WindowsBaltic", "WindowsCyrillic", 
"WindowsEastEurope", "WindowsGreek", "WindowsThai", "WindowsTurkish", 
"ZapfDingbats"}

[edit] Nemerle

How easy is it to present Unicode strings in source code? Very; they can be input directly, or as 'u####' character literals when needed.

Can Unicode literals be written directly, or be part of identifiers/keywords/etc? Yes; identifiers, literals and such can be written directly as UTF8 strings.

How well can the language communicate with the rest of the world? Is it good at input/output with Unicode? Nemerle plays well with the 'rest of the world' (it was developed in Poland and most of its user-base is Polish or Russian, so the 'rest of the world' from the language developers/users perspective is different than that typically envisioned by an Anglophone.) Input/output in UTF8 is handled readily, other encodings, text directions and such are handled by classes in the System.Text and System.Globalization namespaces. See this MSDN page for recommendations on globalization/localization of applications.

Is it convenient to manipulate Unicode strings in the language? Yes; string methods expect UTF8 strings

How broad/deep does the language support Unicode? What encodings (e.g. UTF-8, UTF-16, etc) can be used? Normalization? Using the standard .NET libraries, there is a lot of support for unicode string manipulation. For example, normalization is accomplished by simply calling the Normalize() method on a string.

[edit] Nimrod

Strings are assumed to be UTF-8 in Nimrod.

let c = "abcdé"
let Δ = 12
let e = "$abcde¢£¤¥©ÇßçIJijŁłʒλπ•₠₡₢₣₤₥₦₧₨₩₪₫€₭₮₯₰₱₲₳₴₵₵←→⇒∙⌘☺☻ア字文𪚥"
echo e

[edit] Perl

In Perl, "Unicode" means "UTF-8". If you want to include utf8 characters in your source file, unless you have set PERL_UNICODE environment correctly, you should do
use utf8;
or you risk the parser treating the file as raw bytes. Inside the script, utf8 characters can be used both as identifiers and literal strings, and built-in string functions will respect it:
$四十二 = "voilà";
print "$四十二"; # voilà
print uc($四十二); # VOILÀ
or you can specify unicode characters by name or ordinal:
use charnames qw(greek);
$x = "\N{sigma} \U\N{sigma}";
$y = "\x{2708}";
print scalar reverse("$x $y"); # ✈ Σ σ
Regular expressions also have support for unicode based on properties, for example, finding characters that's normally written from right to left:
print "Say עִבְרִית" =~ /(\p{BidiClass:R})/g;	# עברית
When it comes to IO, one should specify whether a file is to be opened in utf8 or raw byte mode:
open IN, "<:utf8", "file_utf";
open OUT, ">:raw", "file_byte";

The default of IO behavior can also be set in PERL_UNICODE.

However, when your program interacts with the environment, you may still run into tricky spots if you have incompatible locale settings or your OS is not using unicode; that's not what Perl has control over, unfortunately.

[edit] Perl 6

Perl 6 programs and strings are all in Unicode, specced (but not yet entirely implemented) to operate at a grapheme abstraction level, which is agnostic to underlying encodings or normalizations. (These are generally handled at program boundaries.) Opened files default to UTF-8 encoding. All Unicode character properties are in play, so any appropriate characters may be used as parts of identifiers, whitespace, or user-defined operators. For instance:

sub prefix:<> (\𝐕) { 𝐕 ** (1/3) }
say27; # prints 3

Non-Unicode strings are represented as Buf types rather than Str types, and Unicode operations may not be applied to Buf types without some kind of explicit conversion. Only ASCIIish operations are allowed on buffers.

As things develop, Perl 6 intends to support Unicode even better than Perl 5, which already does a great job in recent versions of accessing nearly all Unicode 6.0 functionality. Perl 6 improves on Perl 5 primarily by offering explicitly typed strings that always know which operations are sensical and which are not.

[edit] PicoLisp

PicoLisp can directly handle _only_ Unicode (UTF-8) strings. So the problem is rather how to handle non-Unicode strings: They must be pre- or post-processed by external tools, typically with pipes during I/O. For example, to read a line from a file in 8859 encoding:

(in '(iconv "-f" "ISO-8859-15" "file.txt") (line))

[edit] Python

Python supports writing Unicode literals in any encoding, but you have to declare the encoding being used. This is done by including a special comment as either the first or second line of the source file:

#!/usr/bin/env python
# -*- coding: latin-1 -*-
 
u = 'abcdé'
print(ord(u[-1]))

In Python 3, the default encoding is UTF-8. Before that it was ASCII.

For more info on Unicode in Python, see its how-to.

[edit] Racket

 
#lang racket
 
;; Unicode in strings, using ascii
"\u03bb" ; -> "λ"
;; and since Racket source code is read in UTF-8, Unicode can be used
;; directly
"λ" ; -> same
 
;; The same holds for character constants
#\u3bb ; -> #\λ
#\λ  ; -> same
 
;; And of course Unicode can be used in identifiers,
(define √ sqrt)
(√ 256) ; -> 16
;; and in fact the standard language makes use of some of these
(λ(x) x) ; -> an identity function
 

Further points:

  • IO of strings is the same as IO for code -- using UTF-8
  • Manipulation of Unicode strings is easy; Racket uses UCS-4 for representing strings at runtime (which doesn't affect users)
  • Racket includes additional related functionality, like some Unicode functions (normalization etc), and IO encoding based on iconv to do IO of many other encodings.

[edit] Ruby

Ruby has hardly any specific support for Unicode; however since it focuses on encodings (exactly 100 encodings are supported in Ruby 2.1.0) it includes pretty much all known Unicode Transformation Formats, including UTF-8 which is the default encoding since 2.1.0 .

Most support is to be found in the Regexp engine, for instance /\p{Sc}/ matches everything from the Symbol: Currency category; \p{} matches a character’s Unicode script, like /\p{Linear_B}/.

Unicode strings are no problem:

str = "你好"
str.include?("好") # => true

Unicode code is no problem either:

def Σ(array)
array.inject(:+)
end
 
puts Σ([4,5,6]) #=>15
 

The unicode gem (an external library) is for difficult things like normalization and lowercase\uppercase outside the ASCII region.

[edit] Scala

Library: Scala
object UTF8 extends App {
 
def charToInt(s: String) = {
def charToInt0(c: Char, next: Char): Option[Int] = (c, next) match {
case _ if (c.isHighSurrogate && next.isLowSurrogate) =>
Some(java.lang.Character.toCodePoint(c, next))
case _ if (c.isLowSurrogate) => None
case _ => Some(c.toInt)
}
 
if (s.length > 1) charToInt0(s(0), s(1)) else Some(s.toInt)
}
 
def intToChars(n: Int) = java.lang.Character.toChars(n).mkString
 
println('\uD869'.isHighSurrogate + " " + '\uDEA5'.isLowSurrogate)
 
println(charToInt("\uD869\uDEA5"))
 
val b = "\uD869\uDEA5"
println(b)
 
val c = "\uD834\uDD1E"
println(c)
 
val a = "$abcde¢£¤¥©ÇßçIJijŁłʒλπ•₠₡₢₣₤₥₦₧₨₩₪₫€₭₮₯₰₱₲₳₴₵₵←→⇒∙⌘☺☻ア字文𪚥".
map(c => "%s\t\\u%04X".format(c, c.toInt)).foreach(println)
}
Output:
true true
Some(173733)
𪚥
𝄞
$	\u0024
a	\u0061
b	\u0062
c	\u0063
d	\u0064
e	\u0065
¢	\u00A2
£	\u00A3
¤	\u00A4
¥	\u00A5
©	\u00A9
Ç	\u00C7
ß	\u00DF
ç	\u00E7
IJ	\u0132
ij	\u0133
Ł	\u0141
ł	\u0142
ʒ	\u0292
λ	\u03BB
π	\u03C0
•	\u2022
₠	\u20A0
₡	\u20A1
₢	\u20A2
₣	\u20A3
₤	\u20A4
₥	\u20A5
₦	\u20A6
₧	\u20A7
₨	\u20A8
₩	\u20A9
₪	\u20AA
₫	\u20AB
€	\u20AC
₭	\u20AD
₮	\u20AE
₯	\u20AF
₰	\u20B0
₱	\u20B1
₲	\u20B2
₳	\u20B3
₴	\u20B4
₵	\u20B5
₵	\u20B5
←	\u2190
→	\u2192
⇒	\u21D2
∙	\u2219
⌘	\u2318
☺	\u263A
☻	\u263B
ア	\u30A2
字	\u5B57
文	\u6587
?	\uD869
?	\uDEA5
	\uF8FF

[edit] Seed7

The Unicode encoding of Seed7 characters and strings is UTF-32. Seed7 source files use UTF-8 encoding. Character literals and string literals are therefore written with UTF-8 encoding. Unicode characters are allowed in comments, but not in identifiers and keywords. Functions, which send strings to the operating system convert them to the encoding used by the OS. Strings received by the operating system are converted to UTF-32. Seed7 supports reading and writing Latin-1, UTF-8 and UTF-16 files. Because of UTF-32 there is no distinction between byte and character position.

[edit] Tcl

All characters in Tcl are always Unicode characters, with ordinary string operations (as listed elsewhere on Rosetta Code) always performed on Unicode. Input and output characters are translated from and to the system's native encoding automatically (with this being able to be overridden on a per file-handle basis via fconfigure -encoding). Source files can be written in encodings other than the native encoding — from Tcl 8.5 onwards, the encoding to use for a file can be controlled by the -encoding option to tclsh, wish and source — though it is usually recommended that programmers maximize their portability by writing in the ASCII subset and using the \uXXXX escape sequence for all other characters. Tcl does not handle byte-order marks by default, because that requires deeper understanding of the application level (and sometimes the encoding information is available in metadata anyway, such as when handling HTTP connections).

The way in which characters are encoded in memory is not defined by the Tcl language (the implementation uses byte arrays, UTF-16 arrays and UCS-2 strings as appropriate) and the only characters with any restriction on use as command or variable names are the ASCII parenthesis and colon characters. However, the $var shorthand syntax is much more restricted (to ASCII alphanumeric plus underline only); other cases have to use the more verbose form: [set funny–var–name].

[edit] TXR

TXR source code and I/O are all assumed to be text which is UTF-8 encoded. This is a self-contained implementation, not relying on any encoding library. TXR ignores LANG and such environment variables.

One of the regression test cases uses Japanese text.

Characters can be coded directly, or encoded indirectly with hexadecimal escape sequences.

The regular expression engine, also an original implementation, self-contained within TXR, supports full Unicode (not only the Basic Multilingual Plane, but all planes).

However, as of version 89, identifiers such as variables are restricted to English letters, numbers and underscores.

Whether or not text outside of the Basic Multilingual Plane can actually be represented by a given port of TXR depends on the width of the C compiler's wchar_t type. A 16 bit wchar_t restricts the program to the BMP.

Japanese test case:

@{TITLE /[あ-ん一-耙]+/} (@ROMAJI/@ENGLISH)
@(freeform)
@(coll)@{STANZA /[^\n\x3000 ]+/}@(end)@/.*/
 

Test data: Japanese traditional song:

春が来た (Haru-ga Kita/Spring has Come)

春が来た 春が来た どこに来た
山に来た 里に来た 野にも来た

花が咲く 花が咲く どこに咲く
山に咲く 里に咲く 野にも咲く

鳥がなく 鳥がなく どこでなく
山でなく 里でなく 野でもなく

Expected output (with txr -B):

TITLE="春が来た"
ROMAJI="Haru-ga Kita"
ENGLISH="Spring has Come"
STANZA[0]="春が来た"
STANZA[1]="春が来た"
STANZA[2]="どこに来た"
STANZA[3]="山に来た"
STANZA[4]="里に来た"
STANZA[5]="野にも来た"
STANZA[6]="花が咲く"
STANZA[7]="花が咲く"
STANZA[8]="どこに咲く"
STANZA[9]="山に咲く"
STANZA[10]="里に咲く"
STANZA[11]="野にも咲く"
STANZA[12]="鳥がなく"
STANZA[13]="鳥がなく"
STANZA[14]="どこでなく"
STANZA[15]="山でなく"
STANZA[16]="里でなく"
STANZA[17]="野でもなく"

[edit] UNIX Shell

The Bourne shell does not have any inbuilt Unicode functionality. However, Unicode can be represented as ASCII based hexadecimal number sequences, or by using form of escape sequence encoding, such as \uXXXX. The shell will produce its output in ASCII, but can call other programs to produce the Unicode output. The shell does not have any inbuilt string manipulation utilities, so uses external tools such as cut, expr, grep, sed and awk. These would typically manipulate the hexadecimal sequences to provide string manipulation, or dedicated Unicode based tools could be used.

  • How well prepared is the programming language for Unicode? - Fine. All Unicode strings can be represented as hexadecimal sequences.
  • How easy is it to present Unicode strings in source code? - Easy, they are in hexadecimal.
  • Can Unicode literals be written directly - No
  • or be part of identifiers/keywords/etc? - No
  • How well can the language communicate with the rest of the world? - Extremely well. The shell makes use of all of the tools that a Unix box has to offer.
  • Is it good at input/output with Unicode? - This language is weak on input/output anyway, so its Unicode input/output is also weak. However, the shell makes use of all installed tools, so this is not a problem in real terms.
  • Is it convenient to manipulate Unicode strings in the language? - Not really, the shell is not good at string manipulation. Howver, it makes good use of external programs, so Unicode string manipulation should not be a problem.
  • How broad/deep does the language support Unicode? There is no inbuilt support for Unicode, but all encodings can be represented through hexadecimal strings.

[edit] zkl

zkl doesn't do unicode; all string handling is 8 bit ASCIIZ. The language source is a subset of ASCII. Then again, it doesn't care if you use UTF-8 and provides "\uXXXX" and "\Ux*;" string escapes for up to 31 bit Unicode characters. You can verify a string is valid UTF-8 by using the string len method: "text".len(8). Future support would be in the form of extension libraries that add objects for whatever Unicode form (32 bit, 16 bit, UTF-8, etc) is desired. zkl is designed for this type of extension.

  • Unicode in source: UTF-8 in strings. If your terminal/editor supports UTF-8, you can use the glyphs directly, otherwise, use string escapes to represent the Unicode characters.
  • Unicode identifiers, etc? No
  • Communications with the rest of the world: Byte streams plus methods to change endianness.
  • Can zkl manipulate Unicode? PITA
  • Is there any Unicode support? Only encoding/decoding UTF-8.
  • Future support? If somebody writes the libraries. For example, it is straight forward to write a front end to PCRE and thus acquire a Unicode aware regular expression engine.

[edit] ZX Spectrum Basic

The ZX Spectrum does not have native Unicode support. However, it does support user defined graphics, which makes it is possible to create custom characters in the UDG area. It is possible to represent Unicode by using ASCII based hexadecimal number sequences, or by using a form of escape sequence encoding, such as \uXXXX. However, there is only 48k of memory available on a traditional rubber key ZX Spectrum, (or 128k on some of the plus versions), and 510k would be needed to store the Unicode characters for display, so Unicode is not really viable on this platform.

  • How well prepared is the programming language for Unicode? - Not good. There are no Unicode symbols in the ROM.
  • How easy is it to present Unicode strings in source code? - Easy, they are in hexadecimal.
  • Can Unicode literals be written directly - No
  • or be part of identifiers/keywords/etc? - No
  • How well can the language communicate with the rest of the world? - Not good. There is no TCP/IP stack, and the computer does not have an Ethernet port.
  • Is it good at input/output with Unicode? - Not good. There are no Unicode symbols in ROM, or on the keyboard.
  • Is it convenient to manipulate Unicode strings in the language? - Moderate. The language is not designed for Unicode, so has no inbuilt Unicode functions. However, it is possible to write manipulation routines, and the language is good at arithmetic, so no problem.
  • How broad/deep does the language support Unicode? What encodings (e.g. UTF-8, UTF-16, etc) can be used? There is no inbuilt support for Unicode, but all encodings can be represented through hexadecimal strings. A decoder and output routine would need to be written, but this is easy to do on the Spectrum.
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