def __init__(self, grammar, sent, trace=0):
self._sent = sent
self._parser = SteppingShiftReduceParser(grammar, trace)
# Set up the main window.
self._top = Tk()
self._top.title('Shift Reduce Parser Application')
# Animations. animating_lock is a lock to prevent the demo
# from performing new operations while it's animating.
self._animating_lock = 0
self._animate = IntVar(self._top)
self._animate.set(10) # = medium
# The user can hide the grammar.
self._show_grammar = IntVar(self._top)
self._show_grammar.set(1)
# Initialize fonts.
self._init_fonts(self._top)
# Set up key bindings.
self._init_bindings()
# Create the basic frames.
self._init_menubar(self._top)
self._init_buttons(self._top)
self._init_feedback(self._top)
self._init_grammar(self._top)
self._init_canvas(self._top)
# A popup menu for reducing.
self._reduce_menu = Menu(self._canvas, tearoff=0)
# Reset the demo, and set the feedback frame to empty.
self.reset()
self._lastoper1['text'] = ''
def __init__(self, grammar, sent, trace=0):
self._sent = sent
self._parser = SteppingShiftReduceParser(grammar, trace)
# Set up the main window.
self._top = Tk()
self._top.title('Shift Reduce Parser Application')
# Animations. animating_lock is a lock to prevent the demo
# from performing new operations while it's animating.
self._animating_lock = 0
self._animate = IntVar(self._top)
self._animate.set(10) # = medium
# The user can hide the grammar.
self._show_grammar = IntVar(self._top)
self._show_grammar.set(1)
# Initialize fonts.
self._init_fonts(self._top)
# Set up key bindings.
self._init_bindings()
# Create the basic frames.
self._init_menubar(self._top)
self._init_buttons(self._top)
self._init_feedback(self._top)
self._init_grammar(self._top)
self._init_canvas(self._top)
# A popup menu for reducing.
self._reduce_menu = Menu(self._canvas, tearoff=0)
# Reset the demo, and set the feedback frame to empty.
self.reset()
self._lastoper1['text'] = ''
class ShiftReduceApp(object):
"""
A graphical tool for exploring the shift-reduce parser. The tool
displays the parser's stack and the remaining text, and allows the
user to control the parser's operation. In particular, the user
can shift tokens onto the stack, and can perform reductions on the
top elements of the stack. A "step" button simply steps through
the parsing process, performing the operations that
``nltk.parse.ShiftReduceParser`` would use.
"""
def __init__(self, grammar, sent, trace=0):
self._sent = sent
self._parser = SteppingShiftReduceParser(grammar, trace)
# Set up the main window.
self._top = Tk()
self._top.title('Shift Reduce Parser Application')
# Animations. animating_lock is a lock to prevent the demo
# from performing new operations while it's animating.
self._animating_lock = 0
self._animate = IntVar(self._top)
self._animate.set(10) # = medium
# The user can hide the grammar.
self._show_grammar = IntVar(self._top)
self._show_grammar.set(1)
# Initialize fonts.
self._init_fonts(self._top)
# Set up key bindings.
self._init_bindings()
# Create the basic frames.
self._init_menubar(self._top)
self._init_buttons(self._top)
self._init_feedback(self._top)
self._init_grammar(self._top)
self._init_canvas(self._top)
# A popup menu for reducing.
self._reduce_menu = Menu(self._canvas, tearoff=0)
# Reset the demo, and set the feedback frame to empty.
self.reset()
self._lastoper1['text'] = ''
#########################################
## Initialization Helpers
#########################################
def _init_fonts(self, root):
# See: <http://www.astro.washington.edu/owen/ROTKFolklore.html>
self._sysfont = tkinter.font.Font(font=Button()["font"])
root.option_add("*Font", self._sysfont)
# TWhat's our font size (default=same as sysfont)
self._size = IntVar(root)
self._size.set(self._sysfont.cget('size'))
self._boldfont = tkinter.font.Font(family='helvetica',
weight='bold',
size=self._size.get())
self._font = tkinter.font.Font(family='helvetica',
size=self._size.get())
def _init_grammar(self, parent):
# Grammar view.
self._prodframe = listframe = Frame(parent)
self._prodframe.pack(fill='both', side='left', padx=2)
self._prodlist_label = Label(self._prodframe,
font=self._boldfont,
text='Available Reductions')
self._prodlist_label.pack()
self._prodlist = Listbox(self._prodframe,
selectmode='single',
relief='groove',
background='white',
foreground='#909090',
font=self._font,
selectforeground='#004040',
selectbackground='#c0f0c0')
self._prodlist.pack(side='right', fill='both', expand=1)
self._productions = list(self._parser.grammar().productions())
for production in self._productions:
self._prodlist.insert('end', (' %s' % production))
self._prodlist.config(height=min(len(self._productions), 25))
# Add a scrollbar if there are more than 25 productions.
if 1: #len(self._productions) > 25:
listscroll = Scrollbar(self._prodframe, orient='vertical')
self._prodlist.config(yscrollcommand=listscroll.set)
listscroll.config(command=self._prodlist.yview)
listscroll.pack(side='left', fill='y')
# If they select a production, apply it.
self._prodlist.bind('<<ListboxSelect>>', self._prodlist_select)
# When they hover over a production, highlight it.
self._hover = -1
self._prodlist.bind('<Motion>', self._highlight_hover)
self._prodlist.bind('<Leave>', self._clear_hover)
def _init_bindings(self):
# Quit
self._top.bind('<Control-q>', self.destroy)
self._top.bind('<Control-x>', self.destroy)
self._top.bind('<Alt-q>', self.destroy)
self._top.bind('<Alt-x>', self.destroy)
# Ops (step, shift, reduce, undo)
self._top.bind('<space>', self.step)
self._top.bind('<s>', self.shift)
self._top.bind('<Alt-s>', self.shift)
self._top.bind('<Control-s>', self.shift)
self._top.bind('<r>', self.reduce)
self._top.bind('<Alt-r>', self.reduce)
self._top.bind('<Control-r>', self.reduce)
self._top.bind('<Delete>', self.reset)
self._top.bind('<u>', self.undo)
self._top.bind('<Alt-u>', self.undo)
self._top.bind('<Control-u>', self.undo)
self._top.bind('<Control-z>', self.undo)
self._top.bind('<BackSpace>', self.undo)
# Misc
self._top.bind('<Control-p>', self.postscript)
self._top.bind('<Control-h>', self.help)
self._top.bind('<F1>', self.help)
self._top.bind('<Control-g>', self.edit_grammar)
self._top.bind('<Control-t>', self.edit_sentence)
# Animation speed control
self._top.bind('-', lambda e, a=self._animate: a.set(20))
self._top.bind('=', lambda e, a=self._animate: a.set(10))
self._top.bind('+', lambda e, a=self._animate: a.set(4))
def _init_buttons(self, parent):
# Set up the frames.
self._buttonframe = buttonframe = Frame(parent)
buttonframe.pack(fill='none', side='bottom')
Button(
buttonframe,
text='Step',
background='#90c0d0',
foreground='black',
command=self.step,
).pack(side='left')
Button(buttonframe,
text='Shift',
underline=0,
background='#90f090',
foreground='black',
command=self.shift).pack(side='left')
Button(buttonframe,
text='Reduce',
underline=0,
background='#90f090',
foreground='black',
command=self.reduce).pack(side='left')
Button(buttonframe,
text='Undo',
underline=0,
background='#f0a0a0',
foreground='black',
command=self.undo).pack(side='left')
def _init_menubar(self, parent):
menubar = Menu(parent)
filemenu = Menu(menubar, tearoff=0)
filemenu.add_command(label='Reset Parser',
underline=0,
command=self.reset,
accelerator='Del')
filemenu.add_command(label='Print to Postscript',
underline=0,
command=self.postscript,
accelerator='Ctrl-p')
filemenu.add_command(label='Exit',
underline=1,
command=self.destroy,
accelerator='Ctrl-x')
menubar.add_cascade(label='File', underline=0, menu=filemenu)
editmenu = Menu(menubar, tearoff=0)
editmenu.add_command(label='Edit Grammar',
underline=5,
command=self.edit_grammar,
accelerator='Ctrl-g')
editmenu.add_command(label='Edit Text',
underline=5,
command=self.edit_sentence,
accelerator='Ctrl-t')
menubar.add_cascade(label='Edit', underline=0, menu=editmenu)
rulemenu = Menu(menubar, tearoff=0)
rulemenu.add_command(label='Step',
underline=1,
command=self.step,
accelerator='Space')
rulemenu.add_separator()
rulemenu.add_command(label='Shift',
underline=0,
command=self.shift,
accelerator='Ctrl-s')
rulemenu.add_command(label='Reduce',
underline=0,
command=self.reduce,
accelerator='Ctrl-r')
rulemenu.add_separator()
rulemenu.add_command(label='Undo',
underline=0,
command=self.undo,
accelerator='Ctrl-u')
menubar.add_cascade(label='Apply', underline=0, menu=rulemenu)
viewmenu = Menu(menubar, tearoff=0)
viewmenu.add_checkbutton(label="Show Grammar",
underline=0,
variable=self._show_grammar,
command=self._toggle_grammar)
viewmenu.add_separator()
viewmenu.add_radiobutton(label='Tiny',
variable=self._size,
underline=0,
value=10,
command=self.resize)
viewmenu.add_radiobutton(label='Small',
variable=self._size,
underline=0,
value=12,
command=self.resize)
viewmenu.add_radiobutton(label='Medium',
variable=self._size,
underline=0,
value=14,
command=self.resize)
viewmenu.add_radiobutton(label='Large',
variable=self._size,
underline=0,
value=18,
command=self.resize)
viewmenu.add_radiobutton(label='Huge',
variable=self._size,
underline=0,
value=24,
command=self.resize)
menubar.add_cascade(label='View', underline=0, menu=viewmenu)
animatemenu = Menu(menubar, tearoff=0)
animatemenu.add_radiobutton(label="No Animation",
underline=0,
variable=self._animate,
value=0)
animatemenu.add_radiobutton(label="Slow Animation",
underline=0,
variable=self._animate,
value=20,
accelerator='-')
animatemenu.add_radiobutton(label="Normal Animation",
underline=0,
variable=self._animate,
value=10,
accelerator='=')
animatemenu.add_radiobutton(label="Fast Animation",
underline=0,
variable=self._animate,
value=4,
accelerator='+')
menubar.add_cascade(label="Animate", underline=1, menu=animatemenu)
helpmenu = Menu(menubar, tearoff=0)
helpmenu.add_command(label='About', underline=0, command=self.about)
helpmenu.add_command(label='Instructions',
underline=0,
command=self.help,
accelerator='F1')
menubar.add_cascade(label='Help', underline=0, menu=helpmenu)
parent.config(menu=menubar)
def _init_feedback(self, parent):
self._feedbackframe = feedbackframe = Frame(parent)
feedbackframe.pack(fill='x', side='bottom', padx=3, pady=3)
self._lastoper_label = Label(feedbackframe,
text='Last Operation:',
font=self._font)
self._lastoper_label.pack(side='left')
lastoperframe = Frame(feedbackframe, relief='sunken', border=1)
lastoperframe.pack(fill='x', side='right', expand=1, padx=5)
self._lastoper1 = Label(lastoperframe,
foreground='#007070',
background='#f0f0f0',
font=self._font)
self._lastoper2 = Label(lastoperframe,
anchor='w',
width=30,
foreground='#004040',
background='#f0f0f0',
font=self._font)
self._lastoper1.pack(side='left')
self._lastoper2.pack(side='left', fill='x', expand=1)
def _init_canvas(self, parent):
self._cframe = CanvasFrame(parent,
background='white',
width=525,
closeenough=10,
border=2,
relief='sunken')
self._cframe.pack(expand=1, fill='both', side='top', pady=2)
canvas = self._canvas = self._cframe.canvas()
self._stackwidgets = []
self._rtextwidgets = []
self._titlebar = canvas.create_rectangle(0,
0,
0,
0,
fill='#c0f0f0',
outline='black')
self._exprline = canvas.create_line(0, 0, 0, 0, dash='.')
self._stacktop = canvas.create_line(0, 0, 0, 0, fill='#408080')
size = self._size.get() + 4
self._stacklabel = TextWidget(canvas,
'Stack',
color='#004040',
font=self._boldfont)
self._rtextlabel = TextWidget(canvas,
'Remaining Text',
color='#004040',
font=self._boldfont)
self._cframe.add_widget(self._stacklabel)
self._cframe.add_widget(self._rtextlabel)
#########################################
## Main draw procedure
#########################################
def _redraw(self):
scrollregion = self._canvas['scrollregion'].split()
(cx1, cy1, cx2, cy2) = [int(c) for c in scrollregion]
# Delete the old stack & rtext widgets.
for stackwidget in self._stackwidgets:
self._cframe.destroy_widget(stackwidget)
self._stackwidgets = []
for rtextwidget in self._rtextwidgets:
self._cframe.destroy_widget(rtextwidget)
self._rtextwidgets = []
# Position the titlebar & exprline
(x1, y1, x2, y2) = self._stacklabel.bbox()
y = y2 - y1 + 10
self._canvas.coords(self._titlebar, -5000, 0, 5000, y - 4)
self._canvas.coords(self._exprline, 0, y * 2 - 10, 5000, y * 2 - 10)
# Position the titlebar labels..
(x1, y1, x2, y2) = self._stacklabel.bbox()
self._stacklabel.move(5 - x1, 3 - y1)
(x1, y1, x2, y2) = self._rtextlabel.bbox()
self._rtextlabel.move(cx2 - x2 - 5, 3 - y1)
# Draw the stack.
stackx = 5
for tok in self._parser.stack():
if isinstance(tok, Tree):
attribs = {
'tree_color': '#4080a0',
'tree_width': 2,
'node_font': self._boldfont,
'node_color': '#006060',
'leaf_color': '#006060',
'leaf_font': self._font
}
widget = tree_to_treesegment(self._canvas, tok, **attribs)
widget.label()['color'] = '#000000'
else:
widget = TextWidget(self._canvas,
tok,
color='#000000',
font=self._font)
widget.bind_click(self._popup_reduce)
self._stackwidgets.append(widget)
self._cframe.add_widget(widget, stackx, y)
stackx = widget.bbox()[2] + 10
# Draw the remaining text.
rtextwidth = 0
for tok in self._parser.remaining_text():
widget = TextWidget(self._canvas,
tok,
color='#000000',
font=self._font)
self._rtextwidgets.append(widget)
self._cframe.add_widget(widget, rtextwidth, y)
rtextwidth = widget.bbox()[2] + 4
# Allow enough room to shift the next token (for animations)
if len(self._rtextwidgets) > 0:
stackx += self._rtextwidgets[0].width()
# Move the remaining text to the correct location (keep it
# right-justified, when possible); and move the remaining text
# label, if necessary.
stackx = max(stackx, self._stacklabel.width() + 25)
rlabelwidth = self._rtextlabel.width() + 10
if stackx >= cx2 - max(rtextwidth, rlabelwidth):
cx2 = stackx + max(rtextwidth, rlabelwidth)
for rtextwidget in self._rtextwidgets:
rtextwidget.move(4 + cx2 - rtextwidth, 0)
self._rtextlabel.move(cx2 - self._rtextlabel.bbox()[2] - 5, 0)
midx = (stackx + cx2 - max(rtextwidth, rlabelwidth)) / 2
self._canvas.coords(self._stacktop, midx, 0, midx, 5000)
(x1, y1, x2, y2) = self._stacklabel.bbox()
# Set up binding to allow them to shift a token by dragging it.
if len(self._rtextwidgets) > 0:
def drag_shift(widget, midx=midx, self=self):
if widget.bbox()[0] < midx: self.shift()
else: self._redraw()
self._rtextwidgets[0].bind_drag(drag_shift)
self._rtextwidgets[0].bind_click(self.shift)
# Draw the stack top.
self._highlight_productions()
def _draw_stack_top(self, widget):
# hack..
midx = widget.bbox()[2] + 50
self._canvas.coords(self._stacktop, midx, 0, midx, 5000)
def _highlight_productions(self):
# Highlight the productions that can be reduced.
self._prodlist.selection_clear(0, 'end')
for prod in self._parser.reducible_productions():
index = self._productions.index(prod)
self._prodlist.selection_set(index)
#########################################
## Button Callbacks
#########################################
def destroy(self, *e):
if self._top is None: return
self._top.destroy()
self._top = None
def reset(self, *e):
self._parser.initialize(self._sent)
self._lastoper1['text'] = 'Reset App'
self._lastoper2['text'] = ''
self._redraw()
def step(self, *e):
if self.reduce(): return True
elif self.shift(): return True
else:
if list(self._parser.parses()):
self._lastoper1['text'] = 'Finished:'
self._lastoper2['text'] = 'Success'
else:
self._lastoper1['text'] = 'Finished:'
self._lastoper2['text'] = 'Failure'
def shift(self, *e):
if self._animating_lock: return
if self._parser.shift():
tok = self._parser.stack()[-1]
self._lastoper1['text'] = 'Shift:'
self._lastoper2['text'] = '%r' % tok
if self._animate.get():
self._animate_shift()
else:
self._redraw()
return True
return False
def reduce(self, *e):
if self._animating_lock: return
production = self._parser.reduce()
if production:
self._lastoper1['text'] = 'Reduce:'
self._lastoper2['text'] = '%s' % production
if self._animate.get():
self._animate_reduce()
else:
self._redraw()
return production
def undo(self, *e):
if self._animating_lock: return
if self._parser.undo():
self._redraw()
def postscript(self, *e):
self._cframe.print_to_file()
def mainloop(self, *args, **kwargs):
"""
Enter the Tkinter mainloop. This function must be called if
this demo is created from a non-interactive program (e.g.
from a secript); otherwise, the demo will close as soon as
the script completes.
"""
if in_idle(): return
self._top.mainloop(*args, **kwargs)
#########################################
## Menubar callbacks
#########################################
def resize(self, size=None):
if size is not None: self._size.set(size)
size = self._size.get()
self._font.configure(size=-(abs(size)))
self._boldfont.configure(size=-(abs(size)))
self._sysfont.configure(size=-(abs(size)))
#self._stacklabel['font'] = ('helvetica', -size-4, 'bold')
#self._rtextlabel['font'] = ('helvetica', -size-4, 'bold')
#self._lastoper_label['font'] = ('helvetica', -size)
#self._lastoper1['font'] = ('helvetica', -size)
#self._lastoper2['font'] = ('helvetica', -size)
#self._prodlist['font'] = ('helvetica', -size)
#self._prodlist_label['font'] = ('helvetica', -size-2, 'bold')
self._redraw()
def help(self, *e):
# The default font's not very legible; try using 'fixed' instead.
try:
ShowText(self._top,
'Help: Shift-Reduce Parser Application', (__doc__
or '').strip(),
width=75,
font='fixed')
except:
ShowText(self._top,
'Help: Shift-Reduce Parser Application', (__doc__
or '').strip(),
width=75)
def about(self, *e):
ABOUT = ("NLTK Shift-Reduce Parser Application\n" +
"Written by Edward Loper")
TITLE = 'About: Shift-Reduce Parser Application'
try:
from tkinter.messagebox import Message
Message(message=ABOUT, title=TITLE).show()
except:
ShowText(self._top, TITLE, ABOUT)
def edit_grammar(self, *e):
CFGEditor(self._top, self._parser.grammar(), self.set_grammar)
def set_grammar(self, grammar):
self._parser.set_grammar(grammar)
self._productions = list(grammar.productions())
self._prodlist.delete(0, 'end')
for production in self._productions:
self._prodlist.insert('end', (' %s' % production))
def edit_sentence(self, *e):
sentence = " ".join(self._sent)
title = 'Edit Text'
instr = 'Enter a new sentence to parse.'
EntryDialog(self._top, sentence, instr, self.set_sentence, title)
def set_sentence(self, sent):
self._sent = sent.split() #[XX] use tagged?
self.reset()
#########################################
## Reduce Production Selection
#########################################
def _toggle_grammar(self, *e):
if self._show_grammar.get():
self._prodframe.pack(fill='both',
side='left',
padx=2,
after=self._feedbackframe)
self._lastoper1['text'] = 'Show Grammar'
else:
self._prodframe.pack_forget()
self._lastoper1['text'] = 'Hide Grammar'
self._lastoper2['text'] = ''
def _prodlist_select(self, event):
selection = self._prodlist.curselection()
if len(selection) != 1: return
index = int(selection[0])
production = self._parser.reduce(self._productions[index])
if production:
self._lastoper1['text'] = 'Reduce:'
self._lastoper2['text'] = '%s' % production
if self._animate.get():
self._animate_reduce()
else:
self._redraw()
else:
# Reset the production selections.
self._prodlist.selection_clear(0, 'end')
for prod in self._parser.reducible_productions():
index = self._productions.index(prod)
self._prodlist.selection_set(index)
def _popup_reduce(self, widget):
# Remove old commands.
productions = self._parser.reducible_productions()
if len(productions) == 0: return
self._reduce_menu.delete(0, 'end')
for production in productions:
self._reduce_menu.add_command(label=str(production),
command=self.reduce)
self._reduce_menu.post(self._canvas.winfo_pointerx(),
self._canvas.winfo_pointery())
#########################################
## Animations
#########################################
def _animate_shift(self):
# What widget are we shifting?
widget = self._rtextwidgets[0]
# Where are we shifting from & to?
right = widget.bbox()[0]
if len(self._stackwidgets) == 0: left = 5
else: left = self._stackwidgets[-1].bbox()[2] + 10
# Start animating.
dt = self._animate.get()
dx = (left - right) * 1.0 / dt
self._animate_shift_frame(dt, widget, dx)
def _animate_shift_frame(self, frame, widget, dx):
if frame > 0:
self._animating_lock = 1
widget.move(dx, 0)
self._top.after(10, self._animate_shift_frame, frame - 1, widget,
dx)
else:
# but: stacktop??
# Shift the widget to the stack.
del self._rtextwidgets[0]
self._stackwidgets.append(widget)
self._animating_lock = 0
# Display the available productions.
self._draw_stack_top(widget)
self._highlight_productions()
def _animate_reduce(self):
# What widgets are we shifting?
numwidgets = len(self._parser.stack()[-1]) # number of children
widgets = self._stackwidgets[-numwidgets:]
# How far are we moving?
if isinstance(widgets[0], TreeSegmentWidget):
ydist = 15 + widgets[0].label().height()
else:
ydist = 15 + widgets[0].height()
# Start animating.
dt = self._animate.get()
dy = ydist * 2.0 / dt
self._animate_reduce_frame(dt / 2, widgets, dy)
def _animate_reduce_frame(self, frame, widgets, dy):
if frame > 0:
self._animating_lock = 1
for widget in widgets:
widget.move(0, dy)
self._top.after(10, self._animate_reduce_frame, frame - 1, widgets,
dy)
else:
del self._stackwidgets[-len(widgets):]
for widget in widgets:
self._cframe.remove_widget(widget)
tok = self._parser.stack()[-1]
if not isinstance(tok, Tree): raise ValueError()
label = TextWidget(self._canvas,
str(tok.label()),
color='#006060',
font=self._boldfont)
widget = TreeSegmentWidget(self._canvas, label, widgets, width=2)
(x1, y1, x2, y2) = self._stacklabel.bbox()
y = y2 - y1 + 10
if not self._stackwidgets: x = 5
else: x = self._stackwidgets[-1].bbox()[2] + 10
self._cframe.add_widget(widget, x, y)
self._stackwidgets.append(widget)
# Display the available productions.
self._draw_stack_top(widget)
self._highlight_productions()
# # Delete the old widgets..
# del self._stackwidgets[-len(widgets):]
# for widget in widgets:
# self._cframe.destroy_widget(widget)
#
# # Make a new one.
# tok = self._parser.stack()[-1]
# if isinstance(tok, Tree):
# attribs = {'tree_color': '#4080a0', 'tree_width': 2,
# 'node_font': bold, 'node_color': '#006060',
# 'leaf_color': '#006060', 'leaf_font':self._font}
# widget = tree_to_treesegment(self._canvas, tok.type(),
# **attribs)
# widget.node()['color'] = '#000000'
# else:
# widget = TextWidget(self._canvas, tok.type(),
# color='#000000', font=self._font)
# widget.bind_click(self._popup_reduce)
# (x1, y1, x2, y2) = self._stacklabel.bbox()
# y = y2-y1+10
# if not self._stackwidgets: x = 5
# else: x = self._stackwidgets[-1].bbox()[2] + 10
# self._cframe.add_widget(widget, x, y)
# self._stackwidgets.append(widget)
#self._redraw()
self._animating_lock = 0
#########################################
## Hovering.
#########################################
def _highlight_hover(self, event):
# What production are we hovering over?
index = self._prodlist.nearest(event.y)
if self._hover == index: return
# Clear any previous hover highlighting.
self._clear_hover()
# If the production corresponds to an available reduction,
# highlight the stack.
selection = [int(s) for s in self._prodlist.curselection()]
if index in selection:
rhslen = len(self._productions[index].rhs())
for stackwidget in self._stackwidgets[-rhslen:]:
if isinstance(stackwidget, TreeSegmentWidget):
stackwidget.label()['color'] = '#00a000'
else:
stackwidget['color'] = '#00a000'
# Remember what production we're hovering over.
self._hover = index
def _clear_hover(self, *event):
# Clear any previous hover highlighting.
if self._hover == -1: return
self._hover = -1
for stackwidget in self._stackwidgets:
if isinstance(stackwidget, TreeSegmentWidget):
stackwidget.label()['color'] = 'black'
else:
stackwidget['color'] = 'black'
class ShiftReduceApp(object):
"""
A graphical tool for exploring the shift-reduce parser. The tool
displays the parser's stack and the remaining text, and allows the
user to control the parser's operation. In particular, the user
can shift tokens onto the stack, and can perform reductions on the
top elements of the stack. A "step" button simply steps through
the parsing process, performing the operations that
``nltk.parse.ShiftReduceParser`` would use.
"""
def __init__(self, grammar, sent, trace=0):
self._sent = sent
self._parser = SteppingShiftReduceParser(grammar, trace)
# Set up the main window.
self._top = Tk()
self._top.title('Shift Reduce Parser Application')
# Animations. animating_lock is a lock to prevent the demo
# from performing new operations while it's animating.
self._animating_lock = 0
self._animate = IntVar(self._top)
self._animate.set(10) # = medium
# The user can hide the grammar.
self._show_grammar = IntVar(self._top)
self._show_grammar.set(1)
# Initialize fonts.
self._init_fonts(self._top)
# Set up key bindings.
self._init_bindings()
# Create the basic frames.
self._init_menubar(self._top)
self._init_buttons(self._top)
self._init_feedback(self._top)
self._init_grammar(self._top)
self._init_canvas(self._top)
# A popup menu for reducing.
self._reduce_menu = Menu(self._canvas, tearoff=0)
# Reset the demo, and set the feedback frame to empty.
self.reset()
self._lastoper1['text'] = ''
#########################################
## Initialization Helpers
#########################################
def _init_fonts(self, root):
# See: <http://www.astro.washington.edu/owen/ROTKFolklore.html>
self._sysfont = tkinter.font.Font(font=Button()["font"])
root.option_add("*Font", self._sysfont)
# TWhat's our font size (default=same as sysfont)
self._size = IntVar(root)
self._size.set(self._sysfont.cget('size'))
self._boldfont = tkinter.font.Font(family='helvetica', weight='bold',
size=self._size.get())
self._font = tkinter.font.Font(family='helvetica',
size=self._size.get())
def _init_grammar(self, parent):
# Grammar view.
self._prodframe = listframe = Frame(parent)
self._prodframe.pack(fill='both', side='left', padx=2)
self._prodlist_label = Label(self._prodframe,
font=self._boldfont,
text='Available Reductions')
self._prodlist_label.pack()
self._prodlist = Listbox(self._prodframe, selectmode='single',
relief='groove', background='white',
foreground='#909090',
font=self._font,
selectforeground='#004040',
selectbackground='#c0f0c0')
self._prodlist.pack(side='right', fill='both', expand=1)
self._productions = list(self._parser.grammar().productions())
for production in self._productions:
self._prodlist.insert('end', (' %s' % production))
self._prodlist.config(height=min(len(self._productions), 25))
# Add a scrollbar if there are more than 25 productions.
if 1:#len(self._productions) > 25:
listscroll = Scrollbar(self._prodframe,
orient='vertical')
self._prodlist.config(yscrollcommand = listscroll.set)
listscroll.config(command=self._prodlist.yview)
listscroll.pack(side='left', fill='y')
# If they select a production, apply it.
self._prodlist.bind('<<ListboxSelect>>', self._prodlist_select)
# When they hover over a production, highlight it.
self._hover = -1
self._prodlist.bind('<Motion>', self._highlight_hover)
self._prodlist.bind('<Leave>', self._clear_hover)
def _init_bindings(self):
# Quit
self._top.bind('<Control-q>', self.destroy)
self._top.bind('<Control-x>', self.destroy)
self._top.bind('<Alt-q>', self.destroy)
self._top.bind('<Alt-x>', self.destroy)
# Ops (step, shift, reduce, undo)
self._top.bind('<space>', self.step)
self._top.bind('<s>', self.shift)
self._top.bind('<Alt-s>', self.shift)
self._top.bind('<Control-s>', self.shift)
self._top.bind('<r>', self.reduce)
self._top.bind('<Alt-r>', self.reduce)
self._top.bind('<Control-r>', self.reduce)
self._top.bind('<Delete>', self.reset)
self._top.bind('<u>', self.undo)
self._top.bind('<Alt-u>', self.undo)
self._top.bind('<Control-u>', self.undo)
self._top.bind('<Control-z>', self.undo)
self._top.bind('<BackSpace>', self.undo)
# Misc
self._top.bind('<Control-p>', self.postscript)
self._top.bind('<Control-h>', self.help)
self._top.bind('<F1>', self.help)
self._top.bind('<Control-g>', self.edit_grammar)
self._top.bind('<Control-t>', self.edit_sentence)
# Animation speed control
self._top.bind('-', lambda e,a=self._animate:a.set(20))
self._top.bind('=', lambda e,a=self._animate:a.set(10))
self._top.bind('+', lambda e,a=self._animate:a.set(4))
def _init_buttons(self, parent):
# Set up the frames.
self._buttonframe = buttonframe = Frame(parent)
buttonframe.pack(fill='none', side='bottom')
Button(buttonframe, text='Step',
background='#90c0d0', foreground='black',
command=self.step,).pack(side='left')
Button(buttonframe, text='Shift', underline=0,
background='#90f090', foreground='black',
command=self.shift).pack(side='left')
Button(buttonframe, text='Reduce', underline=0,
background='#90f090', foreground='black',
command=self.reduce).pack(side='left')
Button(buttonframe, text='Undo', underline=0,
background='#f0a0a0', foreground='black',
command=self.undo).pack(side='left')
def _init_menubar(self, parent):
menubar = Menu(parent)
filemenu = Menu(menubar, tearoff=0)
filemenu.add_command(label='Reset Parser', underline=0,
command=self.reset, accelerator='Del')
filemenu.add_command(label='Print to Postscript', underline=0,
command=self.postscript, accelerator='Ctrl-p')
filemenu.add_command(label='Exit', underline=1,
command=self.destroy, accelerator='Ctrl-x')
menubar.add_cascade(label='File', underline=0, menu=filemenu)
editmenu = Menu(menubar, tearoff=0)
editmenu.add_command(label='Edit Grammar', underline=5,
command=self.edit_grammar,
accelerator='Ctrl-g')
editmenu.add_command(label='Edit Text', underline=5,
command=self.edit_sentence,
accelerator='Ctrl-t')
menubar.add_cascade(label='Edit', underline=0, menu=editmenu)
rulemenu = Menu(menubar, tearoff=0)
rulemenu.add_command(label='Step', underline=1,
command=self.step, accelerator='Space')
rulemenu.add_separator()
rulemenu.add_command(label='Shift', underline=0,
command=self.shift, accelerator='Ctrl-s')
rulemenu.add_command(label='Reduce', underline=0,
command=self.reduce, accelerator='Ctrl-r')
rulemenu.add_separator()
rulemenu.add_command(label='Undo', underline=0,
command=self.undo, accelerator='Ctrl-u')
menubar.add_cascade(label='Apply', underline=0, menu=rulemenu)
viewmenu = Menu(menubar, tearoff=0)
viewmenu.add_checkbutton(label="Show Grammar", underline=0,
variable=self._show_grammar,
command=self._toggle_grammar)
viewmenu.add_separator()
viewmenu.add_radiobutton(label='Tiny', variable=self._size,
underline=0, value=10, command=self.resize)
viewmenu.add_radiobutton(label='Small', variable=self._size,
underline=0, value=12, command=self.resize)
viewmenu.add_radiobutton(label='Medium', variable=self._size,
underline=0, value=14, command=self.resize)
viewmenu.add_radiobutton(label='Large', variable=self._size,
underline=0, value=18, command=self.resize)
viewmenu.add_radiobutton(label='Huge', variable=self._size,
underline=0, value=24, command=self.resize)
menubar.add_cascade(label='View', underline=0, menu=viewmenu)
animatemenu = Menu(menubar, tearoff=0)
animatemenu.add_radiobutton(label="No Animation", underline=0,
variable=self._animate, value=0)
animatemenu.add_radiobutton(label="Slow Animation", underline=0,
variable=self._animate, value=20,
accelerator='-')
animatemenu.add_radiobutton(label="Normal Animation", underline=0,
variable=self._animate, value=10,
accelerator='=')
animatemenu.add_radiobutton(label="Fast Animation", underline=0,
variable=self._animate, value=4,
accelerator='+')
menubar.add_cascade(label="Animate", underline=1, menu=animatemenu)
helpmenu = Menu(menubar, tearoff=0)
helpmenu.add_command(label='About', underline=0,
command=self.about)
helpmenu.add_command(label='Instructions', underline=0,
command=self.help, accelerator='F1')
menubar.add_cascade(label='Help', underline=0, menu=helpmenu)
parent.config(menu=menubar)
def _init_feedback(self, parent):
self._feedbackframe = feedbackframe = Frame(parent)
feedbackframe.pack(fill='x', side='bottom', padx=3, pady=3)
self._lastoper_label = Label(feedbackframe, text='Last Operation:',
font=self._font)
self._lastoper_label.pack(side='left')
lastoperframe = Frame(feedbackframe, relief='sunken', border=1)
lastoperframe.pack(fill='x', side='right', expand=1, padx=5)
self._lastoper1 = Label(lastoperframe, foreground='#007070',
background='#f0f0f0', font=self._font)
self._lastoper2 = Label(lastoperframe, anchor='w', width=30,
foreground='#004040', background='#f0f0f0',
font=self._font)
self._lastoper1.pack(side='left')
self._lastoper2.pack(side='left', fill='x', expand=1)
def _init_canvas(self, parent):
self._cframe = CanvasFrame(parent, background='white',
width=525, closeenough=10,
border=2, relief='sunken')
self._cframe.pack(expand=1, fill='both', side='top', pady=2)
canvas = self._canvas = self._cframe.canvas()
self._stackwidgets = []
self._rtextwidgets = []
self._titlebar = canvas.create_rectangle(0,0,0,0, fill='#c0f0f0',
outline='black')
self._exprline = canvas.create_line(0,0,0,0, dash='.')
self._stacktop = canvas.create_line(0,0,0,0, fill='#408080')
size = self._size.get()+4
self._stacklabel = TextWidget(canvas, 'Stack', color='#004040',
font=self._boldfont)
self._rtextlabel = TextWidget(canvas, 'Remaining Text',
color='#004040', font=self._boldfont)
self._cframe.add_widget(self._stacklabel)
self._cframe.add_widget(self._rtextlabel)
#########################################
## Main draw procedure
#########################################
def _redraw(self):
scrollregion = self._canvas['scrollregion'].split()
(cx1, cy1, cx2, cy2) = [int(c) for c in scrollregion]
# Delete the old stack & rtext widgets.
for stackwidget in self._stackwidgets:
self._cframe.destroy_widget(stackwidget)
self._stackwidgets = []
for rtextwidget in self._rtextwidgets:
self._cframe.destroy_widget(rtextwidget)
self._rtextwidgets = []
# Position the titlebar & exprline
(x1, y1, x2, y2) = self._stacklabel.bbox()
y = y2-y1+10
self._canvas.coords(self._titlebar, -5000, 0, 5000, y-4)
self._canvas.coords(self._exprline, 0, y*2-10, 5000, y*2-10)
# Position the titlebar labels..
(x1, y1, x2, y2) = self._stacklabel.bbox()
self._stacklabel.move(5-x1, 3-y1)
(x1, y1, x2, y2) = self._rtextlabel.bbox()
self._rtextlabel.move(cx2-x2-5, 3-y1)
# Draw the stack.
stackx = 5
for tok in self._parser.stack():
if isinstance(tok, Tree):
attribs = {'tree_color': '#4080a0', 'tree_width': 2,
'node_font': self._boldfont,
'node_color': '#006060',
'leaf_color': '#006060', 'leaf_font':self._font}
widget = tree_to_treesegment(self._canvas, tok,
**attribs)
widget.label()['color'] = '#000000'
else:
widget = TextWidget(self._canvas, tok,
color='#000000', font=self._font)
widget.bind_click(self._popup_reduce)
self._stackwidgets.append(widget)
self._cframe.add_widget(widget, stackx, y)
stackx = widget.bbox()[2] + 10
# Draw the remaining text.
rtextwidth = 0
for tok in self._parser.remaining_text():
widget = TextWidget(self._canvas, tok,
color='#000000', font=self._font)
self._rtextwidgets.append(widget)
self._cframe.add_widget(widget, rtextwidth, y)
rtextwidth = widget.bbox()[2] + 4
# Allow enough room to shift the next token (for animations)
if len(self._rtextwidgets) > 0:
stackx += self._rtextwidgets[0].width()
# Move the remaining text to the correct location (keep it
# right-justified, when possible); and move the remaining text
# label, if necessary.
stackx = max(stackx, self._stacklabel.width()+25)
rlabelwidth = self._rtextlabel.width()+10
if stackx >= cx2-max(rtextwidth, rlabelwidth):
cx2 = stackx + max(rtextwidth, rlabelwidth)
for rtextwidget in self._rtextwidgets:
rtextwidget.move(4+cx2-rtextwidth, 0)
self._rtextlabel.move(cx2-self._rtextlabel.bbox()[2]-5, 0)
midx = (stackx + cx2-max(rtextwidth, rlabelwidth))/2
self._canvas.coords(self._stacktop, midx, 0, midx, 5000)
(x1, y1, x2, y2) = self._stacklabel.bbox()
# Set up binding to allow them to shift a token by dragging it.
if len(self._rtextwidgets) > 0:
def drag_shift(widget, midx=midx, self=self):
if widget.bbox()[0] < midx: self.shift()
else: self._redraw()
self._rtextwidgets[0].bind_drag(drag_shift)
self._rtextwidgets[0].bind_click(self.shift)
# Draw the stack top.
self._highlight_productions()
def _draw_stack_top(self, widget):
# hack..
midx = widget.bbox()[2]+50
self._canvas.coords(self._stacktop, midx, 0, midx, 5000)
def _highlight_productions(self):
# Highlight the productions that can be reduced.
self._prodlist.selection_clear(0, 'end')
for prod in self._parser.reducible_productions():
index = self._productions.index(prod)
self._prodlist.selection_set(index)
#########################################
## Button Callbacks
#########################################
def destroy(self, *e):
if self._top is None: return
self._top.destroy()
self._top = None
def reset(self, *e):
self._parser.initialize(self._sent)
self._lastoper1['text'] = 'Reset App'
self._lastoper2['text'] = ''
self._redraw()
def step(self, *e):
if self.reduce(): return True
elif self.shift(): return True
else:
if list(self._parser.parses()):
self._lastoper1['text'] = 'Finished:'
self._lastoper2['text'] = 'Success'
else:
self._lastoper1['text'] = 'Finished:'
self._lastoper2['text'] = 'Failure'
def shift(self, *e):
if self._animating_lock: return
if self._parser.shift():
tok = self._parser.stack()[-1]
self._lastoper1['text'] = 'Shift:'
self._lastoper2['text'] = '%r' % tok
if self._animate.get():
self._animate_shift()
else:
self._redraw()
return True
return False
def reduce(self, *e):
if self._animating_lock: return
production = self._parser.reduce()
if production:
self._lastoper1['text'] = 'Reduce:'
self._lastoper2['text'] = '%s' % production
if self._animate.get():
self._animate_reduce()
else:
self._redraw()
return production
def undo(self, *e):
if self._animating_lock: return
if self._parser.undo():
self._redraw()
def postscript(self, *e):
self._cframe.print_to_file()
def mainloop(self, *args, **kwargs):
"""
Enter the Tkinter mainloop. This function must be called if
this demo is created from a non-interactive program (e.g.
from a secript); otherwise, the demo will close as soon as
the script completes.
"""
if in_idle(): return
self._top.mainloop(*args, **kwargs)
#########################################
## Menubar callbacks
#########################################
def resize(self, size=None):
if size is not None: self._size.set(size)
size = self._size.get()
self._font.configure(size=-(abs(size)))
self._boldfont.configure(size=-(abs(size)))
self._sysfont.configure(size=-(abs(size)))
#self._stacklabel['font'] = ('helvetica', -size-4, 'bold')
#self._rtextlabel['font'] = ('helvetica', -size-4, 'bold')
#self._lastoper_label['font'] = ('helvetica', -size)
#self._lastoper1['font'] = ('helvetica', -size)
#self._lastoper2['font'] = ('helvetica', -size)
#self._prodlist['font'] = ('helvetica', -size)
#self._prodlist_label['font'] = ('helvetica', -size-2, 'bold')
self._redraw()
def help(self, *e):
# The default font's not very legible; try using 'fixed' instead.
try:
ShowText(self._top, 'Help: Shift-Reduce Parser Application',
(__doc__ or '').strip(), width=75, font='fixed')
except:
ShowText(self._top, 'Help: Shift-Reduce Parser Application',
(__doc__ or '').strip(), width=75)
def about(self, *e):
ABOUT = ("NLTK Shift-Reduce Parser Application\n"+
"Written by Edward Loper")
TITLE = 'About: Shift-Reduce Parser Application'
try:
from tkinter.messagebox import Message
Message(message=ABOUT, title=TITLE).show()
except:
ShowText(self._top, TITLE, ABOUT)
def edit_grammar(self, *e):
CFGEditor(self._top, self._parser.grammar(), self.set_grammar)
def set_grammar(self, grammar):
self._parser.set_grammar(grammar)
self._productions = list(grammar.productions())
self._prodlist.delete(0, 'end')
for production in self._productions:
self._prodlist.insert('end', (' %s' % production))
def edit_sentence(self, *e):
sentence = " ".join(self._sent)
title = 'Edit Text'
instr = 'Enter a new sentence to parse.'
EntryDialog(self._top, sentence, instr, self.set_sentence, title)
def set_sentence(self, sent):
self._sent = sent.split() #[XX] use tagged?
self.reset()
#########################################
## Reduce Production Selection
#########################################
def _toggle_grammar(self, *e):
if self._show_grammar.get():
self._prodframe.pack(fill='both', side='left', padx=2,
after=self._feedbackframe)
self._lastoper1['text'] = 'Show Grammar'
else:
self._prodframe.pack_forget()
self._lastoper1['text'] = 'Hide Grammar'
self._lastoper2['text'] = ''
def _prodlist_select(self, event):
selection = self._prodlist.curselection()
if len(selection) != 1: return
index = int(selection[0])
production = self._parser.reduce(self._productions[index])
if production:
self._lastoper1['text'] = 'Reduce:'
self._lastoper2['text'] = '%s' % production
if self._animate.get():
self._animate_reduce()
else:
self._redraw()
else:
# Reset the production selections.
self._prodlist.selection_clear(0, 'end')
for prod in self._parser.reducible_productions():
index = self._productions.index(prod)
self._prodlist.selection_set(index)
def _popup_reduce(self, widget):
# Remove old commands.
productions = self._parser.reducible_productions()
if len(productions) == 0: return
self._reduce_menu.delete(0, 'end')
for production in productions:
self._reduce_menu.add_command(label=str(production),
command=self.reduce)
self._reduce_menu.post(self._canvas.winfo_pointerx(),
self._canvas.winfo_pointery())
#########################################
## Animations
#########################################
def _animate_shift(self):
# What widget are we shifting?
widget = self._rtextwidgets[0]
# Where are we shifting from & to?
right = widget.bbox()[0]
if len(self._stackwidgets) == 0: left = 5
else: left = self._stackwidgets[-1].bbox()[2]+10
# Start animating.
dt = self._animate.get()
dx = (left-right)*1.0/dt
self._animate_shift_frame(dt, widget, dx)
def _animate_shift_frame(self, frame, widget, dx):
if frame > 0:
self._animating_lock = 1
widget.move(dx, 0)
self._top.after(10, self._animate_shift_frame,
frame-1, widget, dx)
else:
# but: stacktop??
# Shift the widget to the stack.
del self._rtextwidgets[0]
self._stackwidgets.append(widget)
self._animating_lock = 0
# Display the available productions.
self._draw_stack_top(widget)
self._highlight_productions()
def _animate_reduce(self):
# What widgets are we shifting?
numwidgets = len(self._parser.stack()[-1]) # number of children
widgets = self._stackwidgets[-numwidgets:]
# How far are we moving?
if isinstance(widgets[0], TreeSegmentWidget):
ydist = 15 + widgets[0].label().height()
else:
ydist = 15 + widgets[0].height()
# Start animating.
dt = self._animate.get()
dy = ydist*2.0/dt
self._animate_reduce_frame(dt/2, widgets, dy)
def _animate_reduce_frame(self, frame, widgets, dy):
if frame > 0:
self._animating_lock = 1
for widget in widgets: widget.move(0, dy)
self._top.after(10, self._animate_reduce_frame,
frame-1, widgets, dy)
else:
del self._stackwidgets[-len(widgets):]
for widget in widgets:
self._cframe.remove_widget(widget)
tok = self._parser.stack()[-1]
if not isinstance(tok, Tree): raise ValueError()
label = TextWidget(self._canvas, str(tok.label()), color='#006060',
font=self._boldfont)
widget = TreeSegmentWidget(self._canvas, label, widgets,
width=2)
(x1, y1, x2, y2) = self._stacklabel.bbox()
y = y2-y1+10
if not self._stackwidgets: x = 5
else: x = self._stackwidgets[-1].bbox()[2] + 10
self._cframe.add_widget(widget, x, y)
self._stackwidgets.append(widget)
# Display the available productions.
self._draw_stack_top(widget)
self._highlight_productions()
# # Delete the old widgets..
# del self._stackwidgets[-len(widgets):]
# for widget in widgets:
# self._cframe.destroy_widget(widget)
#
# # Make a new one.
# tok = self._parser.stack()[-1]
# if isinstance(tok, Tree):
# attribs = {'tree_color': '#4080a0', 'tree_width': 2,
# 'node_font': bold, 'node_color': '#006060',
# 'leaf_color': '#006060', 'leaf_font':self._font}
# widget = tree_to_treesegment(self._canvas, tok.type(),
# **attribs)
# widget.node()['color'] = '#000000'
# else:
# widget = TextWidget(self._canvas, tok.type(),
# color='#000000', font=self._font)
# widget.bind_click(self._popup_reduce)
# (x1, y1, x2, y2) = self._stacklabel.bbox()
# y = y2-y1+10
# if not self._stackwidgets: x = 5
# else: x = self._stackwidgets[-1].bbox()[2] + 10
# self._cframe.add_widget(widget, x, y)
# self._stackwidgets.append(widget)
#self._redraw()
self._animating_lock = 0
#########################################
## Hovering.
#########################################
def _highlight_hover(self, event):
# What production are we hovering over?
index = self._prodlist.nearest(event.y)
if self._hover == index: return
# Clear any previous hover highlighting.
self._clear_hover()
# If the production corresponds to an available reduction,
# highlight the stack.
selection = [int(s) for s in self._prodlist.curselection()]
if index in selection:
rhslen = len(self._productions[index].rhs())
for stackwidget in self._stackwidgets[-rhslen:]:
if isinstance(stackwidget, TreeSegmentWidget):
stackwidget.label()['color'] = '#00a000'
else:
stackwidget['color'] = '#00a000'
# Remember what production we're hovering over.
self._hover = index
def _clear_hover(self, *event):
# Clear any previous hover highlighting.
if self._hover == -1: return
self._hover = -1
for stackwidget in self._stackwidgets:
if isinstance(stackwidget, TreeSegmentWidget):
stackwidget.label()['color'] = 'black'
else:
stackwidget['color'] = 'black'