ANN: Native Unicode support in Pocket Scheme 
Author Message
 ANN: Native Unicode support in Pocket Scheme

Announcing version 0.3.0 of Pocket Scheme, my SIOD-derived R4RS Scheme
interpreter for Windows CE-based H/PCs and P/PCs.  Pocket Scheme now
represents all character data natively in Unicode, allowing manipulation
of Arabic, Hebrew, Cyrillic, Greek, or other non-Latin text data.  

To summarize:

- char->integer may return a value greater than 255. integer->char
accepts values of greater than 255. Both emit/produce the Unicode
encoding instead of R5RS's "order-preserving isomorphisms".

- open-input-file and open-output-file accept an optional mode symbol
argument, specifying one of 'text 'ansi 'unicode 'binary.  Without the
mode parameter, they default to 'text, using the presence or absence of
the Unicode BOM to determine the file format.  'unicode denotes UCS-2
format.  'ansi denotes 8-bit characters in the device's system codepage.

- read-char and write-char when used against a 'unicode file port will
accept or emit UCS-2 representations.  When used against a 'binary file
port, they work one byte at a time, and perform no character translation
at all. Note that socket ports are always binary.

- Any printable character may appear in a Scheme symbol.

- A string, when coerced to a Pocket Scheme raw vector (similar to the
SCM uniform vector or SIOD array), produces a raw vector of type 'word,
not 'byte.

Current limitations:

- Regular expression support is limited to the Latin-1 subset.

- The UI can only display characters with glyphs present in the system
font, as it lacks a way to specify the font to use.

- This version is certainly less stable than its predecessor.

Q.v. http://www.*-*-*.com/



Sun, 16 Sep 2001 03:00:00 GMT  
 
 [ 1 post ] 

 Relevant Pages 

1. ANN: Pocket Scheme 1.0

2. ANN: Pocket Scheme 1.1.0

3. ANN: Pocket Scheme 1.0.3

4. ANN: Pocket Scheme 0.5.4

5. ANN: Pocket Scheme 0.2.4

6. ANN: Pocket Scheme 0.2.3

7. ANN: Pocket Scheme for the P/PC and H/PC

8. ANN: Pocket Scheme for the P/PC and H/PC

9. ANN: Pocket Scheme for the H/PC

10. scheme implementations that support unicode

11. ANN: Randolph Peters' Pocket Forth Utilities

12. Pocket Scheme - second beta, with source

 

 
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