1The Jim Interpreter
2
3A small-footprint implementation of the Tcl programming language.
4
5--------------------------------------------------------------------------------
6WHAT IS JIM?
7--------------------------------------------------------------------------------
8
9Jim is a small footprint implementation of the Tcl programming language
10written from scratch. Currently Jim Tcl is very feature complete with
11an extensive test suite (see the tests directory).
12There are some Tcl commands and features which are not implemented
13(and likely never will be), including namespaces, traces and Tk. However
14Jim Tcl offers a number of both Tcl8.5 and Tcl8.6 features ({*}, dict, lassign,
15tailcall and optional UTF-8 support) and some unique features.
16These unique features include [lambda] with garbage collection, a general GC/references
17system, arrays as syntax sugar for [dict]tionaries, object-based I/O and more.
18
19Other common features of the Tcl programming language are present, like
20the "everything is a string" behaviour, implemented internally as
21dual ported objects to ensure that the execution time does not reflect
22the semantic of the language :)
23
24--------------------------------------------------------------------------------
25WHEN JIM CAN BE USEFUL?
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27
281) If you are writing an application, and want to make it scriptable, with
29Jim you have a way to do it that does not require to link your application
30with a big system. You can include the Jim source directly in your project
31and use the Jim API to write the glue code that makes your application
32scriptable in Jim, with the following advantages:
33
34- Jim is not the next "little language", but it's a Tcl implementation.
35 You can reuse your knowledge if you already Tcl skills, or enjoy
36 the availability of documentation, books, web resources, ...
37 (for example check my online Tcl book at http://www.invece.org/tclwise)
38
39- Jim is simple, 14k lines of core code. If you want to adapt it you can hack
40 the source code to meet the needs of your application. It makes you
41 able to have scripting for default, and avoid external dependences.
42
43 Having scripting support *inside*, and in a way that a given version
44 of your program always gets shipped a given version of Jim, you can
45 write part of your application in Jim itself. Like it happens for
46 Emacs/Elisp, or Gimp/Scheme, both this applications have the interpreter
47 inside.
48
49- Jim is Tcl, and Tcl looks like a configuration file if you want. So
50 if you use Jim you have also a flexible syntax for your config file.
51 This is a valid Tcl script:
52
53 set MyFeature on
54 ifssl {
55 set SslPort 45000
56 use compression
57 }
58
59 It looks like a configuration file, but if you implement the [ifssl]
60 and [use] commands, it's a valid Tcl script.
61
62- Tcl scales with the user. Not all know it, but Tcl is so powerful that
63 you can reprogram the language in itself. Jim support this features
64 of the Tcl programming language. You can write new control structures,
65 use the flexible data types it offers (Lists are a central data structure,
66 with Dictionaries that are also lists). Still Tcl is simpler for the
67 casual programmer, especially if compared to other languages offering
68 small footprint implementations (like Scheme and FORTH).
69
70- Because of the Tcl semantic (pass by value, everything is a command
71 since there are no reserved words), there is a nice API to glue
72 your application with Jim. See under the Jim Tcl manual for more detail.
73
74- Jim is supported. If you need commercial software, contact the original author
75 at 'antirez@gmail.com' or the current maintainer at 'steveb@workware.net.au'.
76
772) The other "field" where Jim can be useful is obviously embedded systems.
78
793) We are working to make Jim as feature-complete as possible, thanks to
80 dynamically loaded extensions it may stay as little as it is today
81 but able to do interesting things for you. So it's not excluded that
82 in the future Jim will be an option as general purpose language.
83 But don't mind, for this there is already the mainstream Tcl
84 implementation ;).
85
86--------------------------------------------------------------------------------
87HOW BIG IS IT?
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89
90Jim with the default extensions configured and compiled with -Os is about 130k.
91Without any extensions, it is about 85k.
92
93--------------------------------------------------------------------------------
94HOW FAST IS IT?
95--------------------------------------------------------------------------------
96
97Jim is in most code faster than Tcl7.6p2 (latest 7.x version),
98and slower than Tcl 8.4.x. You can expect pretty decent performance
99for such a little interpreter.
100
101If you want a more precise measure, there is 'bench.tcl' inside this
102distribution that will run both under Jim and Tcl, so just execute
103it with both the interpreters and see what you get :)
104
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106HOW TO COMPILE
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108
109Jim was tested under Linux, FreeBSD, MacosX, eCos, QNX, Windows XP (mingw, MVC).
110
111To compile jim itself try:
112
113 ./configure
114 make
115
116--------------------------------------------------------------------------------
117EXTENSIONS
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119
120Many optional extensions are included. Some are C extensions and others are pure Tcl.
121Form more information, try:
122
123 ./configure --help
124
125--------------------------------------------------------------------------------
126HOW TO EMBED JIM INTO APPLICATIONS
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128
129See the "examples.api" directory
130
131--------------------------------------------------------------------------------
132HOW TO WRITE EXTENSIONS FOR JIM
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134
135See the extensions shipped with Jim, jim-readline.c, jim-clock.c, glob.tcl and oo.tcl
136
137--------------------------------------------------------------------------------
138COPYRIGHT and LICENSE
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140
141Unless explicitly stated, all files within Jim repository are released
142under following license:
143
144/* Jim - A small embeddable Tcl interpreter
145 *
146 * Copyright 2005 Salvatore Sanfilippo <antirez@invece.org>
147 * Copyright 2005 Clemens Hintze <c.hintze@gmx.net>
148 * Copyright 2005 patthoyts - Pat Thoyts <patthoyts@users.sf.net>
149 * Copyright 2008 oharboe - ��yvind Harboe - oyvind.harboe@zylin.com
150 * Copyright 2008 Andrew Lunn <andrew@lunn.ch>
151 * Copyright 2008 Duane Ellis <openocd@duaneellis.com>
152 * Copyright 2008 Uwe Klein <uklein@klein-messgeraete.de>
153 * Copyright 2008 Steve Bennett <steveb@workware.net.au>
154 * Copyright 2009 Nico Coesel <ncoesel@dealogic.nl>
155 * Copyright 2009 Zachary T Welch zw@superlucidity.net
156 * Copyright 2009 David Brownell
157 *
158 * Redistribution and use in source and binary forms, with or without
159 * modification, are permitted provided that the following conditions
160 * are met:
161 *
162 * 1. Redistributions of source code must retain the above copyright
163 * notice, this list of conditions and the following disclaimer.
164 * 2. Redistributions in binary form must reproduce the above
165 * copyright notice, this list of conditions and the following
166 * disclaimer in the documentation and/or other materials
167 * provided with the distribution.
168 *
169 * THIS SOFTWARE IS PROVIDED BY THE JIM TCL PROJECT ``AS IS'' AND ANY
170 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
171 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
172 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
173 * JIM TCL PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
174 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
175 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
176 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
177 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
178 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
179 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
180 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
181 *
182 * The views and conclusions contained in the software and documentation
183 * are those of the authors and should not be interpreted as representing
184 * official policies, either expressed or implied, of the Jim Tcl Project.
185 */
186--------------------------------------------------------------------------------
187HISTORY
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189
190"first Jim goal: to vent my need to hack on Tcl."
191
192And actually this is exactly why I started Jim, in the first days
193of Jenuary 2005. After a month of hacking Jim was able to run
194simple scripts, now, after two months it started to be clear to
195me that it was not just the next toy to throw away but something
196that may evolve into a real interpreter. In the same time
197Pat Thoyts and Clemens Hintze started to contribute code, so that
198the development of new core commands was faster, and also more
199people hacking on the same code had as result fixes in the API,
200C macros, and so on.
201
202Currently we are at the point that the core interpreter is almost finished
203and it is entering the Beta stage. There is to add some other core command,
204to do a code review to ensure quality of all the parts and to write
205documentation.
206
207We already started to work on extensions like OOP, event loop,
208I/O, networking, regexp. Some extensions are already ready for
209prime time, like the Sqlite extension and the ANSI I/O.
210
211------------------------------------------------------------------------------
212Thanks to...
213------------------------------------------------------------------------------
214
215- First of all, thanks to every guy that are listed in the AUTHORS file,
216 that directly helped with code and ideas. Also check the ChangeLog
217 file for additional credits about patches or bug reports.
218- Elisa Manara that helped me to select this ill conceived name for
219 an interpreter.
220- Many people on the Tclers Chat that helped me to explore issues
221 about the use and the implementation of the Tcl programming language.
222- David Welton for the tech info sharing and our chats about
223 programming languages design and the ability of software to "scale down".
224- Martin S. Weber for the great help with Solaris issues, debugging of
225 problems with [load] on this arch, 64bit tests.
226- The authors of "valgrind", for this wonderful tool, that helped me a
227 lot to fix bugs in minutes instead of hours.
228
229
230----
231Enjoy!
232Salvatore Sanfilippo
23310 Mar 2005
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236