Scheme interpreter in Python
Lizpop is Scheme interpreter in Python.
Lizpop requires Python 2.5 or later, but does not work in Python3.
Simply run python setup.py install.
e.g.$ tar zxvf lizpop-0.4.0.tar.gz $ cd lizpop-0.4.0 $ sudo python setup.py install
To run interactively:
$ python -O -m lizpop.run
To run a Scheme script in a file:
$ python -O -m lizpop.run yourfile.scm
For more info about command-line options:
$ python -O -m lizpop.run -h
Subset of Scheme R5RS
See the Restrictions section for more details.
Has interfaces to Python
e.g.$ cat helloworld.py def hello(s="world"): return u"Hello %s!" % s.capitalize() $ python -O -m lizpop.run > (define *helloworld* (import "helloworld")) > (define hello (attr *helloworld* 'hello)) > (hello "friends") "Hello Friends!"
For more details, See the IFPY.rst file in this package.
Regular Expression literal.
The following literal is a Regular Expression Object.#/PATTERN/FLAGS PATTERN: Regular expression pattern FLAGS: Regular expression flags. i-- ignore case m-- multi-line s-- dot matches all u-- Unicode dependent L-- locale dependent x-- verbose
Examples;; A simple matching > (re-search #/(\d+):(\d+)/ "Aug 14") ;; not match #f > (re-search #/(\d+):(\d+)/ "Aug 14 08:30") ;; match <_sre.SRE_Match object at ...> ;; Get subgroup > (re-group (re-search #/(\d+):(\d+)/ "Aug 14 08:30") 1 2) ("08" "30") ;; Replace string > (re-gsub #/<(\/?)h\d>/i "<\\1H3>" "<h1>Features:</h1>") "<H3>Features:</H3>" >
For more info, run help procedure.e.g. > (help-list #/(^re-)|(regex)/) > (help re-match re-search re-group re-gsub)
Supports multi-byte characters
Only utf-8 encoding now.
EML is a template language for embedding Lizpop code in text file.
EML has the following simple specifications.
%>STRING<% is a new string literal, but escape sequences in STRING (such as \n and \u3055) are not decoded.
Implicitly, %> is added to the beginning of the input-port.
Implicitly, <% is added to the end of the input-port.
Note: These ideas are inspired by BRL ( http://brl.sourceforge.net/ ).
To run EML, use -eml as command line option.e.g. python -m lizpop.run -eml yourfile.eml
A simple example$ cat gcdlcm.eml <% (define numlist (map string->number *args*)) %> GCD of <% numlist %> is <%(apply gcd numlist)%>. LCM of <% numlist %> is <%(apply lcm numlist)%>. $ python -m lizpop.run -eml gcdlcm.eml -- 1533 37303 4307 GCD of (1533 37303 4307) is 73. LCM of (1533 37303 4307) is 6602631.
For more examples:
please run (help load-eml) to see its help message.
Note: `lizpop + apache2 + mod_wsgi`
See the wsgi_sample/application.wsgi file included in this package.
Lizpop has a help-function, it displays documentation for the given procedures or macros.
(help var …)
e.g.> (help invoke) Procedure: (invoke OBJ MESSAGE ARGS ... ) Invokes the OBJ's method named MESSAGE with ARGS ... .........................................................
However, for now, the help documentation is provided only for the Python-Interface related functions.
For more info, run (help) and (help help-list).
I’m not good at English. So help messages may include some errors or unnatural expressions in English.
Hygienic macros are not supported.
define-syntax syntax-rules, and let-syntax are not implemented.
- Instead, traditional(non-hygienic) macros can be used.
=> run (help define-macro)
Strings are not mutable.
Lizpop strings are implemented as Python unicode-string objects which are immutable. so, string-set! and string-fill! don’t work.
call/cc and dynamic-wind are only partially implemented.
Lizpop does not support full continuation.
Lizpop’s call-with-current-continuation is upward-only and non-reentrant. So, it can be used for non-local-exit, but cannot be used for co-routines or backtracking.
Complex numbers and Fractional numbers are not supported.
null-environment and scheme-report-environment are not implemented.
For more info, run (help eval).
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