- First stub of read line interface

git-svn-id: http://galileo.dmi.unict.it/svn/relational/trunk@227 014f5005-505e-4b48-8d0a-63407b615a7c

relational_readline/linegui.py

@@ -0,0 +1,136 @@
+# -*- coding: utf-8 -*-
+# coding=UTF-8
+# Relational
+# Copyright (C) 2010  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 sys
+
+from relational import relation, parser, optimizer
+
+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'''
+        self.options.append(option)
+        self.options.sort()
+    
+    def remove_completion(self,option):
+        '''Removes one completion from the list of the valid completion options'''
+        #//TODO
+        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)]
+                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(['LIST','LOAD ','UNLOAD ','HELP','QUIT','SAVE '])
+
+
+
+def load_relation(filename,defname=None):
+    if not os.path.isfile(filename):
+        print >> sys.stderr, "%s is not a file" % filename
+        return None
+
+    f=filename.split('/')
+    if defname==None:
+        defname=f[len(f)-1].lower()
+        if (defname.endswith(".csv") or defname.endswith(".tlb")): #removes the extension
+            defname=defname[:-4]
+
+    try:
+        relations[defname]=relation.relation(filename)
+        return defname
+    except Exception, e:
+        print e
+        return None
+    
+def exec_line(command):
+    command=command.strip()
+    if command=='QUIT':
+        sys.exit(0)
+    elif command=='HELP':
+        #//TODO
+        pass
+    elif command=='LIST':         #Lists all the loaded relations
+        for i in relations:
+            print i
+    elif command.startswith('LOAD '):      #Loads a relation
+        pars=command.split(' ')
+        filename=pars[1]
+        if len(pars)>2:
+            defname=pars[2]
+        else:
+            defname=None
+        defname=load_relation(filename,defname)
+        if defname==None: return
+        
+        completer.add_completion(defname)
+        print "Loaded relation %s"% defname
+         
+    elif command=='UNLOAD ':
+        #//TODO
+        pass
+    #elif command=='SAVE': //TODO
+    else:
+        print "Invalid command %s" % command
+def main(files=[]):
+    readline.set_completer(completer.complete)
+
+    readline.parse_and_bind('tab: complete')
+    readline.parse_and_bind('set editing-mode vi')
+
+    while True:
+        line = raw_input('> ')
+        exec_line(line)
+
+
+
+
+main()