relational/relational_readline/linegui.py

339 lines
10 KiB
Python

# Relational
# Copyright (C) 2010-2016 Salvo "LtWorf" Tomaselli
#
# Relational is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
# author Salvo "LtWorf" Tomaselli <tiposchi@tiscali.it>
# Initial readline code from
# http://www.doughellmann.com/PyMOTW/readline/index.html
import readline
import logging
import os.path
import os
import sys
from relational import relation, parser, rtypes
from relational import maintenance
from xtermcolor import colorize
PROMPT_COLOR = 0xffff00
ERROR_COLOR = 0xff0000
TTY = os.isatty(0) and os.isatty(1)
def printtty(*args, **kwargs):
'''
Prints only if stdout and stdin are a tty
'''
if TTY:
print(*args,**kwargs)
class SimpleCompleter(object):
'''Handles completion'''
def __init__(self, options):
'''Takes a list of valid completion options'''
self.options = sorted(options)
return
def add_completion(self, option):
'''Adds one string to the list of the valid completion options'''
if option not in self.options:
self.options.append(option)
self.options.sort()
def remove_completion(self, option):
'''Removes one completion from the list of the valid completion options'''
if option in self.options:
self.options.remove(option)
pass
def complete(self, text, state):
response = None
if state == 0:
# This is the first time for this text, so build a match list.
if text:
self.matches = [s
for s in self.options
if s and s.startswith(text)]
# Add the completion for files here
try:
d = os.path.dirname(text)
listf = os.listdir(d)
d += "/"
except:
d = ""
listf = os.listdir('.')
for i in listf:
i = (d + i).replace('//', '/')
if i.startswith(text):
if os.path.isdir(i):
i = i + "/"
self.matches.append(i)
logging.debug('%s matches: %s', repr(text), self.matches)
else:
self.matches = self.options[:]
logging.debug('(empty input) matches: %s', self.matches)
# Return the state'th item from the match list,
# if we have that many.
try:
response = self.matches[state]
except IndexError:
response = None
logging.debug('complete(%s, %s) => %s',
repr(text), state, repr(response))
return response
relations = {}
completer = SimpleCompleter(
['SURVEY', 'LIST', 'LOAD ', 'UNLOAD ', 'HELP ', 'QUIT', 'SAVE ', '_PRODUCT ', '_UNION ', '_INTERSECTION ',
'_DIFFERENCE ', '_JOIN ', '_LJOIN ', '_RJOIN ', '_FJOIN ', '_PROJECTION ', '_RENAME_TO ', '_SELECTION ', '_RENAME ', '_DIVISION '])
def load_relation(filename, defname=None):
if not os.path.isfile(filename):
print (colorize(
"%s is not a file" % filename, ERROR_COLOR), file=sys.stderr)
return None
f = filename.split('/')
if defname == None:
defname = f[len(f) - 1].lower()
if defname.endswith(".csv"): # removes the extension
defname = defname[:-4]
if not rtypes.is_valid_relation_name(defname):
print (colorize(
"%s is not a valid relation name" % defname, ERROR_COLOR), file=sys.stderr)
return
try:
relations[defname] = relation.relation(filename)
completer.add_completion(defname)
printtty(colorize("Loaded relation %s" % defname, 0x00ff00))
return defname
except Exception as e:
print (colorize(e, ERROR_COLOR), file=sys.stderr)
return None
def survey():
'''performs a survey'''
post = {'software': 'Relational algebra (cli)', 'version': version}
fields = ('System', 'Country', 'School', 'Age', 'How did you find',
'email (only if you want a reply)', 'Comments')
for i in fields:
a = input('%s: ' % i)
post[i] = a
maintenance.send_survey(post)
def help(command):
'''Prints help on the various functions'''
p = command.split(' ', 1)
if len(p) == 1:
print ('HELP command')
print (
'To execute a query:\n[relation =] query\nIf the 1st part is omitted, the result will be stored in the relation last_.')
print (
'To prevent from printing the relation, append a ; to the end of the query.')
print (
'To insert relational operators, type _OPNAME, they will be internally replaced with the correct symbol.')
print (
'Rember: the tab key is enabled and can be very helpful if you can\'t remember something.')
return
cmd = p[1]
if cmd == 'QUIT':
print ('Quits the program')
elif cmd == 'LIST':
print ('Lists the relations loaded')
elif cmd == 'LOAD':
print ('LOAD filename [relationame]')
print ('Loads a relation into memory')
elif cmd == 'UNLOAD':
print ('UNLOAD relationame')
print ('Unloads a relation from memory')
elif cmd == 'SAVE':
print ('SAVE filename relationame')
print ('Saves a relation in a file')
elif cmd == 'HELP':
print ('Prints the help on a command')
elif cmd == 'SURVEY':
print ('Fill and send a survey')
else:
print ('Unknown command: %s' % cmd)
def exec_line(command):
command = command.strip()
if command.startswith(';'):
return
elif command == 'QUIT':
sys.exit(0)
elif command.startswith('HELP'):
help(command)
elif command == 'LIST': # Lists all the loaded relations
for i in relations:
if not i.startswith('_'):
print (i)
elif command == 'SURVEY':
survey()
elif command.startswith('LOAD '): # Loads a relation
pars = command.split(' ')
if len(pars) == 1:
print (colorize("Missing parameter", ERROR_COLOR))
return
filename = pars[1]
if len(pars) > 2:
defname = pars[2]
else:
defname = None
load_relation(filename, defname)
elif command.startswith('UNLOAD '):
pars = command.split(' ')
if len(pars) < 2:
print (colorize("Missing parameter", ERROR_COLOR))
return
if pars[1] in relations:
del relations[pars[1]]
completer.remove_completion(pars[1])
else:
print (colorize("No such relation %s" % pars[1], ERROR_COLOR))
pass
elif command.startswith('SAVE '):
pars = command.split(' ')
if len(pars) != 3:
print (colorize("Missing parameter", ERROR_COLOR))
return
filename = pars[1]
defname = pars[2]
if defname not in relations:
print (colorize("No such relation %s" % defname, ERROR_COLOR))
return
try:
relations[defname].save(filename)
except Exception as e:
print (colorize(e, ERROR_COLOR))
else:
exec_query(command)
def replacements(query):
'''This funcion replaces ascii easy operators with the correct ones'''
query = query.replace(u'_PRODUCT', parser.PRODUCT)
query = query.replace(u'_UNION', parser.UNION)
query = query.replace(u'_INTERSECTION', parser.INTERSECTION)
query = query.replace(u'_DIFFERENCE', parser.DIFFERENCE)
query = query.replace(u'_JOIN', parser.JOIN)
query = query.replace(u'_LJOIN', parser.JOIN_LEFT)
query = query.replace(u'_RJOIN', parser.JOIN_RIGHT)
query = query.replace(u'_FJOIN', parser.JOIN_FULL)
query = query.replace(u'_PROJECTION', parser.PROJECTION)
query = query.replace(u'_RENAME_TO', parser.ARROW)
query = query.replace(u'_SELECTION', parser.SELECTION)
query = query.replace(u'_RENAME', parser.RENAME)
query = query.replace(u'_DIVISION', parser.DIVISION)
return query
def exec_query(command):
'''This function executes a query and prints the result on the screen
if the command terminates with ";" the result will not be printed
'''
# If it terminates with ; doesn't print the result
if command.endswith(';'):
command = command[:-1]
printrel = False
else:
printrel = True
# Performs replacements for weird operators
command = replacements(command)
# Finds the name in where to save the query
parts = command.split('=', 1)
relname,query = maintenance.UserInterface.split_query(command)
# Execute query
try:
pyquery = parser.parse(query)
result = pyquery(relations)
printtty(colorize("-> query: %s" % pyquery, 0x00ff00))
if printrel:
print ()
print (result)
relations[relname] = result
completer.add_completion(relname)
except Exception as e:
print (colorize(str(e), ERROR_COLOR))
def main(files=[]):
printtty(colorize('> ', PROMPT_COLOR) + "; Type HELP to get the HELP")
printtty(colorize('> ', PROMPT_COLOR) +
"; Completion is activated using the tab (if supported by the terminal)")
for i in files:
load_relation(i)
readline.set_completer(completer.complete)
readline.parse_and_bind('tab: complete')
readline.parse_and_bind('set editing-mode emacs')
readline.set_completer_delims(" ")
while True:
try:
line = input(colorize('> ' if TTY else '', PROMPT_COLOR))
if isinstance(line, str) and len(line) > 0:
exec_line(line)
except KeyboardInterrupt:
if TTY:
print ('^C\n')
continue
else:
break
except EOFError:
printtty()
sys.exit(0)
if __name__ == "__main__":
main()