Further clean-up of interfaces

src/sage/interfaces/expect.py

@@ -98,10 +98,10 @@ class gc_disabled(object):
         sage: gc.isenabled()
         True
         sage: with gc_disabled():
-        ...       print gc.isenabled()
-        ...       with gc_disabled():
-        ...           print gc.isenabled()
-        ...       print gc.isenabled()
+        ....:     print gc.isenabled()
+        ....:     with gc_disabled():
+        ....:         print gc.isenabled()
+        ....:     print gc.isenabled()
         False
         False
         False
@@ -530,8 +530,26 @@ def quit(self, verbose=False, timeout=0.25):
         return
 
     def _quit_string(self):
+        """
+        Return the string which will be used to quit the application.
+
+        EXAMPLES::
+
+            sage: gp._quit_string()
+            '\\q'
+            sage: maxima._quit_string()
+            'quit();'
+        """
         return 'quit'
 
+    def _send_interrupt(self):
+        """
+        Send an interrupt to the application.  This is used internally
+        by :meth:`interrupt`.
+        """
+        self._expect.sendline(chr(3))
+        self._expect.sendline(self._quit_string())
+
     def _local_tmpfile(self):
         """
         Return a filename that is used to buffer long command lines for this interface
@@ -552,7 +570,7 @@ def _local_tmpfile(self):
             sage: gap._local_tmpfile() is gap._local_tmpfile()
             True
 
-        The following two problems were fixed in #10004.
+        The following two problems were fixed in :trac:`10004`.
 
         1. Different interfaces have different temp-files::
 
@@ -563,9 +581,8 @@ def _local_tmpfile(self):
            function have different temp-files::
 
             sage: @parallel
-            ... def f(n):
-            ...     return gap._local_tmpfile()
-            ...
+            ....: def f(n):
+            ....:     return gap._local_tmpfile()
             sage: L = [t[1] for t in f(range(5))]
             sage: len(set(L))
             5
@@ -620,25 +637,6 @@ def _remove_tmpfile_from_server(self):
         if not (self.__remote_tmpfile is None):
             raise NotImplementedError
 
-    def read(self, filename):
-        r"""
-        EXAMPLES::
-
-            sage: filename = tmp_filename()
-            sage: f = open(filename, 'w')
-            sage: f.write('x = 2\n')
-            sage: f.close()
-            sage: octave.read(filename)  # optional - octave
-            sage: octave.get('x')        #optional
-            ' 2'
-            sage: import os
-            sage: os.unlink(filename)
-        """
-        self.eval(self._read_in_file_command(filename))
-
-    def _read_in_file_command(self, filename):
-        raise NotImplementedError
-
     def _eval_line_using_file(self, line, restart_if_needed=True):
         """
         Evaluate a line of commands, using a temporary file.
@@ -917,15 +915,14 @@ def interrupt(self, tries=20, timeout=0.3, quit_on_fail=True):
         success = False
         try:
             for i in range(tries):
-                E.sendline(chr(3))
-                E.sendline(self._quit_string())
+                self._send_interrupt()
                 try:
                     E.expect(self._prompt, timeout=timeout)
-                    success= True
-                    break
                 except (pexpect.TIMEOUT, pexpect.EOF) as msg:
-                    #print msg
                     pass
+                else:
+                    success = True
+                    break
         except Exception as msg:
             pass
         if success:
@@ -951,19 +948,6 @@ def _before(self):
         """
         return self._expect.before
 
-    def _interrupt(self):
-        for i in range(15):
-            try:
-                self._sendstr('quit;\n'+chr(3))
-                self._expect_expr(timeout=2)
-            except pexpect.TIMEOUT:
-                pass
-            except pexpect.EOF:
-                self._crash_msg()
-                self.quit()
-            else:
-                return
-
     def _expect_expr(self, expr=None, timeout=None):
         r"""
         Wait for a given expression expr (which could be a regular
@@ -1160,7 +1144,7 @@ def _synchronize(self, cmd='1+%s;\n'):
                 self._expect_expr(s,timeout=0.5)
                 self._expect_expr(timeout=0.5)
         except pexpect.TIMEOUT:
-            self._interrupt()
+            self.interrupt()
         except pexpect.EOF:
             self._crash_msg()
             self.quit()
@@ -1381,9 +1365,8 @@ def __init__(self, interface, silent=False, stdout=None):
         EXAMPLE::
 
             sage: from sage.interfaces.expect import StdOutContext
-            sage: with StdOutContext(gp):
-            ...       gp('1+1')
-            ...
+            sage: with StdOutContext(Gp()) as g:
+            ....:     g('1+1')
             sage=...
         """
         self.interface = interface
@@ -1396,29 +1379,28 @@ def __enter__(self):
 
             sage: from sage.interfaces.expect import StdOutContext
             sage: with StdOutContext(singular):
-            ...       singular.eval('1+1')
-            ...
+            ....:     singular.eval('1+1')
             1+1;
             ...
         """
         if self.silent:
-            return
+            return self.interface
         if self.interface._expect is None:
             self.interface._start()
         self._logfile_backup = self.interface._expect.logfile
         if self.interface._expect.logfile:
             self.interface._expect.logfile = Multiplex(self.interface._expect.logfile, self.stdout)
         else:
             self.interface._expect.logfile = Multiplex(self.stdout)
+        return self.interface
 
     def __exit__(self, typ, value, tb):
         """
         EXAMPLE::
 
             sage: from sage.interfaces.expect import StdOutContext
             sage: with StdOutContext(gap):
-            ...       gap('1+1')
-            ...
+            ....:     gap('1+1')
             $sage...
         """
         if self.silent:

src/sage/interfaces/gap.py

@@ -1167,7 +1167,7 @@ def _start(self):
         except Exception:
             if self.__use_workspace_cache and first_try:
                 first_try = False
-                self.quit(timeout=0)
+                self.quit()
                 gap_reset_workspace(verbose=False)
                 Expect._start(self, "Failed to start GAP.")
                 self._session_number = n

src/sage/interfaces/interface.py

@@ -97,9 +97,6 @@ def _pre_interact(self):
     def _post_interact(self):
         pass
 
-    def __del__(self):
-        pass
-
     def cputime(self):
         """
         CPU time since this process started running.
@@ -115,7 +112,7 @@ def read(self, filename):
             sage: f.write('x = 2\n')
             sage: f.close()
             sage: octave.read(filename)  # optional - octave
-            sage: octave.get('x')        #optional
+            sage: octave.get('x')        # optional - octave
             ' 2'
             sage: import os
             sage: os.unlink(filename)
@@ -125,34 +122,8 @@ def read(self, filename):
     def _read_in_file_command(self, filename):
         raise NotImplementedError
 
-    def eval(self, code, locals=None, **kwds):
-        """
-        INPUT:
-
-
-        -  ``code`` - text to evaluate
-
-        - ``locals`` - None (ignored); this is used for compatibility with the
-          Sage notebook's generic system interface.
-
-        -  ``**kwds`` - All other arguments are passed onto
-           the _eval_line method. An often useful example is
-           reformat=False.
-        """
-
-        if not isinstance(code, basestring):
-            raise TypeError('input code must be a string.')
-
-        #Remove extra whitespace
-        code = code.strip()
-
-        try:
-            pass
-        # DO NOT CATCH KeyboardInterrupt, as it is being caught
-        # by _eval_line
-        # In particular, do NOT call self._keyboard_interrupt()
-        except TypeError as s:
-            raise TypeError('error evaluating "%s":\n%s'%(code,s))
+    def eval(self, code, **kwds):
+        raise NotImplementedError
 
     _eval_line = eval