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@@ -3,14 +3,14 @@ README: Tcl Tcl is maintained, enhanced, and distributed freely as a service to the Tcl community by Scriptics Corporation. -RCS: @(#) $Id: README,v 1.15 1999/02/26 22:25:04 hershey Exp $ +RCS: @(#) $Id: README,v 1.16 1999/04/16 00:46:29 stanton Exp $ Contents -------- 1. Introduction 2. Documentation 3. Compiling and installing Tcl - 4. Summary of changes in Tcl 8.0 + 4. Summary of changes in Tcl 8.1 5. Development tools 6. Tcl newsgroup 7. Tcl contributed archive @@ -31,23 +31,23 @@ variety of web-related tasks and for creating powerful command languages for applications. This directory contains the sources and documentation for Tcl. The -information here corresponds to release 8.0.5, which is the fifth -patch update for Tcl 8.0. This patch provides bug fixes and -incorporates user-contributed patches. Please check the changes file -for details. - -Tcl 8.0 is a major release that replaces the core of the interpreter -with an on-the-fly bytecode compiler to improve execution speed. It -also includes several other new features such as namespaces and binary -I/O, plus many bug fixes. The compiler introduces a few -incompatibilities that may affect existing Tcl scripts; the -incompatibilities are relatively obscure but may require modifications -to some old scripts before they can run with this version. The -compiler introduces many new C-level APIs, but the old APIs are still -supported. See below for more details. +information here corresponds to release 8.1b3, which is the third +beta release for Tcl 8.1. This release is mostly feature complete but +may have bugs and be missing some minor features. This release is for +early adopters who are willing to help us find and fix problems. +Please let us know about any problems you uncover. + +Tcl 8.1 includes four major new features: Unicode support (all internal +strings are now stored in UTF-8 form), a new regular expression matcher +with most of the Perl features, support for multithreading, and a new +message catalog package. For details on features, incompatibilities, and +potential problems with this release, see the Tcl/Tk 8.1 Web page at +http://www.scriptics.com/software/8.1.html or refer to the "changes" file +in this directory, which contains a historical record of all changes to +Tcl. Tcl is a freely available open source package. You can do virtually -anything you like with it, such as modifying it, redistributing it , +anything you like with it, such as modifying it, redistributing it, and selling it either in whole or in part. See the file "license.terms" for complete information. @@ -143,138 +143,87 @@ compiling under UNIX, "win" if you're compiling under Windows, or in the README file in that directory for compiling Tcl, installing it, and running the test suite. -4. Summary of changes in Tcl 8.0 +4. Summary of changes in Tcl 8.1 -------------------------------- -Here are the most significant changes in Tcl 8.0. In addition to these +Here are the most significant changes in Tcl 8.1. In addition to these changes, there are several smaller changes and bug fixes. See the file "changes" for a complete list of all changes. - 1. Bytecode compiler. The core of the Tcl interpreter has been - replaced with an on-the-fly compiler that translates Tcl scripts to - byte codes; a new interpreter then executes the byte codes. In - earlier versions of Tcl, strings were used as a universal - representation; in Tcl 8.0 strings are replaced with Tcl_Obj - structures ("objects") that can hold both a string value and an - internal form such as a binary integer or compiled bytecodes. The - new objects make it possible to store information in efficient - internal forms and avoid the constant translations to and from - strings that occurred with the old interpreter. We have not yet - converted all of Tcl to take full advantage of the compiler and - objects and have not converted any of Tk yet, but even so you - should see speedups of 2-3x on many programs and you may see - speedups as much as 10-20x in some cases (such as code that - manipulates long lists). Future releases should achieve even - greater speedups. The compiler introduces only a few minor changes - at the level of Tcl scripts, but it introduces many new C APIs for - managing objects. See, for example, the manual entries doc/*Obj*.3. - - 2. Namespaces. There is a new namespace mechanism based on the - namespace implementation by Michael McLennan of Cadence. - This includes new "namespace" and "variable" commands. There are - many new C APIs associated with namespaces, but they will not be - exported until Tcl 8.1. Note: the syntax of the namespace command - has been changed slightly since the b1 release. See the changes - file for details. - - 3. Binary I/O. The new object system in Tcl 8.0 supports binary - strings (internally, strings are counted in addition to being null - terminated). There is a new "binary" command for inserting and - extracting data to/from binary strings. Commands such as "puts", - "gets", and "read" commands now operate correctly on binary data. - There is a new variable tcl_platform(byteOrder) to identify the - native byte order for the current host. - - 4. Random numbers. The "expr" command now contains a random number - generator, which can be accessed via the "rand()" and "srand()" math - functions. - - 5. Safe-Tcl enhancements. There is a new "hidden command" - mechanism, implemented with the Tcl commands "interp hide", "interp - expose", "interp invokehidden", and "interp hidden" and the C APIs - Tcl_HideCommand and Tcl_ExposeCommand. There is now support for - safe packages and extension loading, including new library - procedures such as safe::interpCreate (see the manual entry safe.n - for details). - - 6. There is a new package "registry" available under Windows for - accessing the Windows registry. - - 7. There is a new command "file attributes" for getting and setting - things like permissions and owner. There is also a new command - "file nativename" for getting back the platform-specific name for a - particular file. - - 8. There is a new "fcopy" command to copy data between channels. - This replaces and improves upon the not-so-secret unsupported old - command "unsupported0". - - 9. There is a new package "http" for doing GET, POST, and HEAD - requests via the HTTP/1.0 protocol. See the manual entry http.n - for details. - - 10. There are new library procedures for finding word breaks in - strings. See the manual entry library.n for details. - - 11. There are new C APIs Tcl_Finalize (for cleaning up before - unloading the Tcl DLL) and Tcl_Ungets for pushing bytes back into a - channel's input buffer. - - 12. Tcl now supports serial I/O devices on Windows and Unix, with a - new fconfigure -mode option. The Windows driver does not yet - support event-driven I/O. - - 13. The lsort command has new options -dictionary and -index. The - -index option allows for very rapid sorting based on an element - of a list. - - 14. The event notifier has been completely rewritten (again). It - should now allow Tcl to use an external event loop (like Motif's) - when it is embedded in other applications. No script-level - interfaces have changed, but many of the C APIs have. - -Tcl 8.0 introduces the following incompatibilities that may affect Tcl -scripts that worked under Tcl 7.6 and earlier releases: - - 1. Variable and command names may not include the character sequence - "::" anymore: this sequence is now used as a namespace separator. - - 2. The semantics of some Tcl commands have been changed slightly to - maximize performance under the compiler. These incompatibilities - are documented on the Web so that we can keep the list up-to-date. - See the following URL: - - http://www.scriptics.com/doc/compiler.html - - 3. 2-digit years are now parsed differently by the "clock" command - to handle year 2000 issues better (years 00-38 are treated as - 2000-2038 instead of 1900-1938). - - 4. The old Macintosh commands "cp", "mkdir", "mv", "rm", and "rmdir" - are no longer supported; all of these features are now available on - all platforms via the "file" command. - - 5. The variable tcl_precision is now shared between interpreters - and defaults to 12 digits instead of 6; safe interpreters cannot - modify tcl_precision. The new object system in Tcl 8.0 causes - floating-to-string conversions (and the associated rounding) to - occur much less often than in Tcl 7.6, which can sometimes cause - behavioral changes. - - 6. The C APIs associated with the notifier have changed substantially. - - 7. The procedures Tcl_CreateModalTimeout and Tcl_DeleteModalTimeout - have been removed. - - 8. Tcl_CreateFileHandler and Tcl_DeleteFileHandler now take Unix - fd's and are only supported on the Unix platform - - 9. The C APIs for creating channel drivers have changed as part of - the new notifier implementation. The Tcl_File interfaces have been - removed. Tcl_GetChannelFile has been replaced with - Tcl_GetChannelHandle. Tcl_MakeFileChannel now takes a platform- - specific file handle. Tcl_DriverGetOptionProc procedures now take - an additional interp argument. + 1. Internationalization. Tcl has undergone a major revision to + support international character sets: + + All strings in Tcl are now represented in UTF-8 instead of ASCII, + so that Tcl now supports the full Unicode character set. The + representation of ASCII characters is unchanged (in UTF-8 anything + that looks like an ASCII character is an ASCII character), but + characters with the high-order bit set, such as those in ISO-8859, + are represented with multi-byte sequences, as are all Unicode + characters with values greater than 127. This change does not + affect Tcl scripts but it does affect C code that parses strings. + Tcl automatically translates between UTF-8 and the normal encoding + for the platform during interactions with the system. + + In Tcl scripts the backslash sequence \u can be used to enter + 16-bit Unicode characters. \o and \x generate only 8-bit + characters as before. + + There is a new "encoding" command that allows scripts to determine + what encodings are available as well as to convert strings between + different encodings. The fconfigure command now supports a + -encoding option for specifying the encoding of an open file or + socket. Tcl will automatically translate between the specified + encoding and UTF-8 during I/O. + + There are several new C APIs that support UTF-8 and various + encodings. See the manual entry Utf.3 for procedures that + translate between Unicode and UTF-8 and manipulate UTF-8 strings. + See Encoding.3 for procedures that create new encodings and + translate between encodings. See ToUpper.3 for procedures that + perform case conversions on UTF-8 strings. + + 2. Binary data. Binary data is handled differently in Tcl 8.1 + than in Tcl 8.0. Tcl 8.1 uses the UTF-8 facilities to represent + binary data: the character value zero is represented with a + multi-byte sequence, so that (once again) strings in Tcl 8.1 never + contain null bytes. This means that binary data is now accepted + everywhere in Tcl and Tk (in Tcl 8.0 the support for binary data + was incomplete). If you have C code that needs to manipulate the + bytes of binary data (as opposed to just passing the data through) + you should use a new object type called "byte array". See the + manual entry ByteArrObj.3 for information about procedures such as + Tcl_GetByteArrayFromObj. + + 3. Regular expressions. Tcl 8.1 contains a brand new + implementation of regular expressions from Henry Spencer. The + regular expression syntax has been greatly expanded to include + most of the features in Perl. In addition, the regexp engine + supports Unicode and binary data. See the doc/regexp.n manual + entry for more details. + + 4. Threads. If configured with the --enable-threads flag, Tcl can + now be compiled for use in a multi-threaded application. + Individual threads are allowed to use one or more interpreters as + long as each interpreter (and any slave interpreters) is only + accessed by one thread. Each thread runs its own event loop, and + you can post events to other threads. There are new C APIs for + mutexes, condition variables, and thread local storage. See the + doc/Thread.3 manual entry for more details. Tk 8.1 is not yet + multi-thread safe. There is not yet support for tcl level use of + threading except for a test command. (Compile tcltest and try + testthread.) + + 5. Message catalog. There is a new message catalog package which makes + it easy to localize the strings in a script. See the doc/msgcat.n + manual entry for more details. + + 6. Stubbs library for building extensions. There is now a new + way to build extensions for Tcl. Instead of linking with the + tcl shared library you can now link to a stubs library that gets + built in this release. By linking with the stubs library it + is possible to use dynamically loaded extensions in staticlly + built applications. It will also be possible for some extensions + to work for both Tcl 8.0 & 8.1 with out having to recompile. 5. Development tools -------------------- |