def normal_form(diagram, normalizer=None, **params):
"""
Applies normal form to a pregroup diagram of the form
`word @ ... @ word >> cups` by normalising the words and the sentences
seperately before combining them, so it can be drawn using `grammar.draw`.
"""
words, is_pregroup = Id(Ty()), True
for _, box, right in diagram.layers:
if isinstance(box, Word):
if right: # word boxes should be tensored left to right.
is_pregroup = False
break
words = words @ box
else:
break
wires = diagram[len(words):]
is_pregroup = is_pregroup and all(
isinstance(box, Cup) or isinstance(box, Swap) or isinstance(box, Cap)
for box in wires.boxes)
if not is_pregroup:
raise ValueError(messages.expected_pregroup())
norm = lambda d: monoidal.Diagram.normal_form(
d, normalizer=normalizer or Diagram.normalize, **params)
return norm(words) >> norm(wires)
def draw(diagram, **params):
"""
Draws a pregroup diagram, i.e. of shape :code:`word @ ... @ word >> cups`.
Parameters
----------
width : float, optional
Width of the word triangles, default is :code:`2.0`.
space : float, optional
Space between word triangles, default is :code:`0.5`.
textpad : pair of floats, optional
Padding between text and wires, default is :code:`(0.1, 0.2)`.
draw_type_labels : bool, optional
Whether to draw type labels, default is :code:`True`.
aspect : string, optional
Aspect ratio, one of :code:`['equal', 'auto']`.
margins : tuple, optional
Margins, default is :code:`(0.05, 0.05)`.
fontsize : int, optional
Font size for the words, default is :code:`12`.
fontsize_types : int, optional
Font size for the types, default is :code:`12`.
figsize : tuple, optional
Figure size.
path : str, optional
Where to save the image, if :code:`None` we call :code:`plt.show()`.
pretty_types : bool, optional
Whether to draw type labels with superscript, default is :code:`False`.
triangles : bool, optional
Whether to draw words as triangular states, default is :code:`False`.
Raises
------
ValueError
Whenever the input is not a pregroup diagram.
"""
from discopy.rigid import Swap
if not isinstance(diagram, Diagram):
raise TypeError(messages.type_err(Diagram, diagram))
words, is_pregroup = Id(Ty()), True
for _, box, right in diagram.layers:
if isinstance(box, Word):
if right: # word boxes should be tensored left to right.
is_pregroup = False
break
words = words @ box
else:
break
cups = diagram[len(words):].foliation().boxes\
if len(words) < len(diagram) else []
is_pregroup = is_pregroup and words and all(
isinstance(box, Cup) or isinstance(box, Swap) for s in cups
for box in s.boxes)
if not is_pregroup:
raise ValueError(messages.expected_pregroup())
drawing.pregroup_draw(words, cups, **params)
def test_pregroup_draw_errors():
n = Ty('n')
with raises(TypeError):
draw(0)
with raises(ValueError) as err:
draw(Cap(n, n.l))
with raises(ValueError) as err:
draw(Cup(n, n.r))
with raises(ValueError) as err:
draw(Word('Alice', n) >> Word('Alice', n) @ Id(n))
assert str(err.value) is messages.expected_pregroup()
def draw(diagram, **params):
"""
Draws a pregroup diagram, i.e. one slice of word boxes followed by any
number of slices of cups.
Parameters
----------
width : float, optional
Width of the word triangles, default is :code:`2.0`.
space : float, optional
Space between word triangles, default is :code:`0.5`.
textpad : pair of floats, optional
Padding between text and wires, default is :code:`(0.1, 0.2)`.
draw_types : bool, optional
Whether to draw type labels, default is :code:`True`.
aspect : string, optional
Aspect ratio, one of :code:`['equal', 'auto']`.
margins : tuple, optional
Margins, default is :code:`(0.05, 0.05)`.
fontsize : int, optional
Font size for the words, default is :code:`12`.
fontsize_types : int, optional
Font size for the types, default is :code:`12`.
figsize : tuple, optional
Figure size.
path : str, optional
Where to save the image, if `None` we call :code:`plt.show()`.
Raises
------
ValueError
Whenever the input is not a pregroup diagram.
"""
if not isinstance(diagram, Diagram):
raise TypeError(messages.type_err(Diagram, diagram))
words, *cups = diagram.foliation().boxes
is_pregroup = all(isinstance(box, Word) for box in words.boxes)\
and all(isinstance(box, Cup) for s in cups for box in s.boxes)
if not is_pregroup:
raise ValueError(messages.expected_pregroup())
drawing.pregroup_draw(words, cups, **params)