lizpop is a scheme interpreter for Python.
Installation
Simply run python setup.py install.
e.g.
tar zxvf lizpop-0.3.1.tar.gz
cd lizpop-0.3.1
sudo python setup.py install
Usage
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
Features
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(EMbedded Lizpop)
EML is a template language for embedding Lizpop code in text file.
EML has the following simple specifications.
%>STRING 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.
Help function
Lizpop has a help-function, it displays documentation for the given procedures or macros.
Usage:
(help var ...)
(help-list regex-pattern)
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).
Note:
I'm not good at English. So help messages may include some errors or unnatural expressions in English.
Restrictions
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).
Product's homepage
Requirements:
· Python
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