def _pick_candidate(self, scored_candidates):
""" From a sorted list of >1 scored candidates, pick a move to make """
num_candidates = len(scored_candidates)
common = Wordbase.dawg_common() # List of playable common words
playable_candidates = []
# Iterate through the candidates in descending score order
# until we have enough playable ones or we have exhausted the list
i = 0 # Candidate index
p = 0 # Playable index
while p < self._play_one_of and i < num_candidates:
m = scored_candidates[i][0] # Candidate move
w = m.word() # The principal word being played
if len(w) == 2 or w in common:
# This one is playable - but we still won't put it on
# the candidate list if has the same score as the
# first (top-scoring) playable word
if p == 1 and scored_candidates[i][1] == playable_candidates[0][1]:
pass
else:
playable_candidates.append(scored_candidates[i])
p += 1
i += 1
# Now we have a list of up to self._play_one_of playable moves
if p == 0:
# No playable move: give up and do an Exchange or Pass instead
return None
# Pick a move at random from the playable list
return playable_candidates[randint(0, p - 1)][0]
def _pick_candidate(self, scored_candidates):
""" From a sorted list of >1 scored candidates, pick a move to make """
num_candidates = len(scored_candidates)
common = Wordbase.dawg_common() # List of playable common words
playable_candidates = []
# Iterate through the candidates in descending score order
# until we have enough playable ones or we have exhausted the list
i = 0 # Candidate index
p = 0 # Playable index
while p < self._play_one_of and i < num_candidates:
m = scored_candidates[i][0] # Candidate move
w = m.word() # The principal word being played
if len(w) == 2 or w in common:
# This one is playable - but we still won't put it on
# the candidate list if has the same score as the
# first (top-scoring) playable word
if p == 1 and scored_candidates[i][1] == playable_candidates[
0][1]:
pass
else:
playable_candidates.append(scored_candidates[i])
p += 1
i += 1
# Now we have a list of up to self._play_one_of playable moves
if p == 0:
# No playable move: give up and do an Exchange or Pass instead
return None
# Pick a move at random from the playable list
return playable_candidates[randint(0, p - 1)][0]
def _generate_candidates(self):
""" Generate a fresh candidate list """
self.candidates = []
# Start by generating all possible permutations of the
# rack that form left parts of words, ordering them by length
if len(self._rack) > 1:
lpn = LeftPermutationNavigator(self._rack)
Wordbase.dawg().navigate(lpn)
else:
lpn = None
# Generate moves in one-dimensional space by looking at each axis
# (row or column) on the board separately
if self._board.is_empty():
# Special case for first move: only consider the vertical
# central axis (any move played there can identically be
# played horizontally), and with only one anchor in the
# middle square
axis = self._axis_from_column(Board.SIZE // 2)
axis.init_crosschecks()
# Mark the center anchor
axis.mark_anchor(Board.SIZE // 2)
axis.generate_moves(lpn)
else:
# Normal move: go through all 15 (row) + 15 (column) axes and generate
# valid moves within each of them
for r in range(Board.SIZE):
axis = self._axis_from_row(r)
axis.init_crosschecks()
axis.generate_moves(lpn)
for c in range(Board.SIZE):
axis = self._axis_from_column(c)
axis.init_crosschecks()
axis.generate_moves(lpn)
# Delete the reference to LeftPermutationNavigator to save memory
lpn = None
def _gen_moves_from_anchor(self, index, maxleft, lpn):
""" Find valid moves emanating (on the left and right) from this anchor """
if maxleft == 0 and index > 0 and not self.is_empty(index - 1):
# We have a left part already on the board: try to complete it
leftpart = u''
ix = index
while ix > 0 and not self.is_empty(ix - 1):
leftpart = self._sq[ix - 1]._letter + leftpart
ix -= 1
# Use the ExtendRightNavigator to find valid words with this left part
nav = LeftFindNavigator(leftpart)
Wordbase.dawg().navigate(nav)
ns = nav.state()
if ns is not None:
# We found a matching prefix in the graph
matched, prefix, nextnode = ns
# assert matched == leftpart
nav = ExtendRightNavigator(self, index, self._rack)
Navigation(nav).resume(prefix, nextnode, leftpart)
return
# We are not completing an existing left part
# Begin by extending an empty prefix to the right, i.e. placing
# tiles on the anchor square itself and to its right
nav = ExtendRightNavigator(self, index, self._rack)
Wordbase.dawg().navigate(nav)
if maxleft > 0 and lpn is not None:
# Follow this by an effort to permute left prefixes into the open space
# to the left of the anchor square
for leftlen in range(1, maxleft + 1):
lplist = lpn.leftparts(leftlen)
if lplist is not None:
for leftpart, rackleave, prefix, nextnode in lplist:
nav = ExtendRightNavigator(self, index, rackleave)
Navigation(nav).resume(prefix, nextnode, leftpart)
def _generate_candidates(self):
""" Generate a fresh candidate list """
self._candidates = []
# Start by generating all possible permutations of the
# rack that form left parts of words, ordering them by length
if len(self._rack) > 1:
lpn = LeftPermutationNavigator(self._rack)
Wordbase.dawg().navigate(lpn)
else:
lpn = None
# Generate moves in one-dimensional space by looking at each axis
# (row or column) on the board separately
if self._board.is_empty():
# Special case for first move: only consider the vertical
# central axis (any move played there can identically be
# played horizontally), and with only one anchor in the
# middle square
axis = self._axis_from_column(Board.SIZE // 2)
axis.init_crosschecks()
# Mark the center anchor
axis.mark_anchor(Board.SIZE // 2)
axis.generate_moves(lpn)
else:
# Normal move: go through all 15 (row) + 15 (column) axes and generate
# valid moves within each of them
for r in range(Board.SIZE):
axis = self._axis_from_row(r)
axis.init_crosschecks()
axis.generate_moves(lpn)
for c in range(Board.SIZE):
axis = self._axis_from_column(c)
axis.init_crosschecks()
axis.generate_moves(lpn)
def init_crosschecks(self):
""" Calculate and return a list of cross-check bit patterns for the indicated axis """
# The cross-check set is the set of letters that can appear in a square
# and make cross words (above/left and/or below/right of the square) valid
board = self._autoplayer.board()
# Prepare to visit all squares on the axis
x, y = self.coordinate_of(0)
xd, yd = self.coordinate_step()
# Fetch the default cross-check bits, which depend on the rack.
# If the rack contains a wildcard (blank tile), the default cc set
# contains all letters in the Alphabet. Otherwise, it contains the
# letters in the rack.
all_cc = self._autoplayer.rack_bit_pattern()
# Go through the open squares and calculate their cross-checks
for ix in range(Board.SIZE):
cc = all_cc # Start with the default cross-check set
if not board.is_covered(x, y):
if self.is_horizontal():
above = board.letters_above(x, y)
below = board.letters_below(x, y)
else:
above = board.letters_left(x, y)
below = board.letters_right(x, y)
query = u'' if not above else above
query += u'?'
if below:
query += below
if len(query) > 1:
# Nontrivial cross-check: Query the word database for words that fit this pattern
matches = Wordbase.dawg().find_matches(query, sort = False) # Don't need a sorted result
bits = 0
if matches:
cix = 0 if not above else len(above)
# Note the set of allowed letters here
bits = Alphabet.bit_pattern([wrd[cix] for wrd in matches])
# Reduce the cross-check set by intersecting it with the allowed set.
# If the cross-check set and the rack have nothing in common, this
# will lead to the square being marked as closed, which saves
# calculation later on
cc &= bits
# Initialize the square
self._sq[ix].init(self._autoplayer, x, y, cc)
# Keep track of empty squares within the axis in a bit pattern for speed
if self._sq[ix].is_empty():
self._empty_bits |= (1 << ix)
x += xd
y += yd
def lookup_word(db, w, at_sentence_start):
""" Lookup simple or compound word in database and return its meanings """
# Start with a simple lookup
m = db.meanings(w)
if at_sentence_start or not m:
# No meanings found in database, or at sentence start
# Try a lowercase version of the word, if different
lower_w = w.lower()
if lower_w != w:
# Do another lookup, this time for lowercase only
if not m:
m = db.meanings(lower_w)
else:
m.extend(db.meanings(lower_w))
if not m and (lower_w != w or w[0] == '['):
# Still nothing: check abbreviations
m = lookup_abbreviation(w)
if not m and w[0] == '[':
# Could be an abbreviation with periods at the start of a sentence:
# Lookup a lowercase version
m = lookup_abbreviation(lower_w)
if m and w[0] == '[':
# Remove brackets from known abbreviations
w = w[1:-1]
if not m:
# Still nothing: check compound words
cw = Wordbase.dawg().slice_compound_word(lower_w)
if cw:
# This looks like a compound word:
# use the meaning of its last part
prefix = "-".join(cw[0:-1])
m = db.meanings(cw[-1])
m = [ (prefix + "-" + stem, ix, wtype, wcat, prefix + "-" + wform, gform)
for stem, ix, wtype, wcat, wform, gform in m]
return (w, m)
def _lookup(w, at_sentence_start, lookup):
""" Lookup a simple or compound word in the database and return its meaning(s) """
def lookup_abbreviation(w):
""" Lookup abbreviation from abbreviation list """
# Remove brackets, if any, before lookup
clean_w = w[1:-1] if w[0] == '[' else w
# Return a single-entity list with one meaning
m = Abbreviations.DICT.get(clean_w, None)
return None if m is None else [ BIN_Meaning._make(m) ]
# Start with a simple lookup
m = lookup(w)
if at_sentence_start or not m:
# No meanings found in database, or at sentence start
# Try a lowercase version of the word, if different
lower_w = w.lower()
if lower_w != w:
# Do another lookup, this time for lowercase only
if not m:
m = lookup(lower_w)
else:
m.extend(lookup(lower_w))
if not m and (lower_w != w or w[0] == '['):
# Still nothing: check abbreviations
m = lookup_abbreviation(w)
if not m and w[0] == '[':
# Could be an abbreviation with periods at the start of a sentence:
# Lookup a lowercase version
m = lookup_abbreviation(lower_w)
if m and w[0] == '[':
# Remove brackets from known abbreviations
w = w[1:-1]
if not m and BIN_Db._ADJECTIVE_TEST in lower_w:
# Not found: Check whether this might be an adjective
# ending in 'legur'/'leg'/'legt'/'legir'/'legar' etc.
for aend, beyging in AdjectiveTemplate.ENDINGS:
if lower_w.endswith(aend) and len(lower_w) > len(aend):
prefix = lower_w[0 : len(lower_w) - len(aend)]
# Construct an adjective descriptor
if m is None:
m = []
m.append(BIN_Meaning(prefix + "legur", 0, "lo", "alm", lower_w, beyging))
if not m:
# Still nothing: check compound words
cw = Wordbase.dawg().slice_compound_word(w)
if not cw and lower_w != w:
# If not able to slice in original case, try lower case
cw = Wordbase.dawg().slice_compound_word(lower_w)
if cw:
# This looks like a compound word:
# use the meaning of its last part
prefix = "-".join(cw[0:-1])
m = lookup(cw[-1])
m = [ BIN_Meaning(prefix + "-" + r.stofn, r.utg, r.ordfl, r.fl,
prefix + "-" + r.ordmynd, r.beyging)
for r in m]
if not m and lower_w.startswith('ó'):
# Check whether an adjective without the 'ó' prefix is found in BÍN
# (i.e. create 'óhefðbundinn' from 'hefðbundinn')
suffix = lower_w[1:]
if suffix:
om = lookup(suffix)
if om:
m = [ BIN_Meaning("ó" + r.stofn, r.utg, r.ordfl, r.fl,
"ó" + r.ordmynd, r.beyging)
for r in om if r.ordfl == "lo" ]
# noinspection PyRedundantParentheses
return (w, m)
def _load(self):
""" Load word lists into memory from static preprocessed text files """
if self._dawg is not None:
# Already loaded, nothing to do
return
self._dawg = Wordbase.dawg()
def _lookup(w, at_sentence_start, auto_uppercase, lookup):
""" Lookup a simple or compound word in the database and return its meaning(s) """
def lookup_abbreviation(w):
""" Lookup abbreviation from abbreviation list """
# Remove brackets, if any, before lookup
if w[0] == '[':
clean_w = w[1:-1]
# Check for abbreviation that also ended a sentence and
# therefore had its end period cut off
if not clean_w.endswith('.'):
clean_w += '.'
else:
clean_w = w
# Return a single-entity list with one meaning
m = Abbreviations.DICT.get(clean_w, None)
return None if m is None else [BIN_Meaning._make(m)]
# Start with a straightforward lookup of the word
if auto_uppercase and w.islower():
if len(w) == 1:
# Special case for single letter words:
# if they exist in BÍN, don't convert them
m = lookup(w)
if not m:
# If they don't exist in BÍN, treat them as uppercase
# abbreviations (probably middle names)
w = w.upper() + '.'
else:
# Check whether this word has an uppercase form in the database
w_upper = w.capitalize()
m = lookup(w_upper)
if m:
# Yes: assume it should be uppercase
w = w_upper
at_sentence_start = False # No need for special case here
else:
# No: go for the regular lookup
m = lookup(w)
else:
m = lookup(w)
if at_sentence_start or not m:
# No meanings found in database, or at sentence start
# Try a lowercase version of the word, if different
lower_w = w.lower()
if lower_w != w:
# Do another lookup, this time for lowercase only
if not m:
# This is a word that contains uppercase letters
# and was not found in BÍN in its original form
# Try an abbreviation before doing a lowercase lookup
# (since some abbreviations are also words, i.e. LÍN)
m = lookup_abbreviation(w)
if not m:
m = lookup(lower_w)
elif w[0] == '[':
# Remove brackets from known abbreviations
w = w[1:-1]
else:
m.extend(lookup(lower_w))
if m:
# Most common path out of this function
return (w, m)
if (lower_w != w or w[0] == '['):
# Still nothing: check abbreviations
m = lookup_abbreviation(w)
if not m and w[0] == '[':
# Could be an abbreviation with periods at the start of a sentence:
# Lookup a lowercase version
m = lookup_abbreviation(lower_w)
if m and w[0] == '[':
# Remove brackets from known abbreviations
w = w[1:-1]
if not m and BIN_Db._ADJECTIVE_TEST in lower_w:
# Not found: Check whether this might be an adjective
# ending in 'legur'/'leg'/'legt'/'legir'/'legar' etc.
llw = len(lower_w)
for aend, beyging in AdjectiveTemplate.ENDINGS:
if lower_w.endswith(aend) and llw > len(aend):
prefix = lower_w[0:llw - len(aend)]
# Construct an adjective descriptor
if m is None:
m = []
m.append(
BIN_Meaning(prefix + "legur", 0, "lo", "alm", lower_w,
beyging))
if lower_w.endswith("lega") and llw > 4:
# For words ending with "lega", add a possible adverb meaning
if m is None:
m = []
m.append(BIN_Meaning(lower_w, 0, "ao", "ob", lower_w, "-"))
if not m:
# Still nothing: check compound words
cw = Wordbase.dawg().slice_compound_word(w)
if not cw and lower_w != w:
# If not able to slice in original case, try lower case
cw = Wordbase.dawg().slice_compound_word(lower_w)
if cw:
# This looks like a compound word:
# use the meaning of its last part
prefix = "-".join(cw[0:-1])
m = lookup(cw[-1])
if lower_w != w and not at_sentence_start:
# If this is an uppercase word in the middle of a
# sentence, allow only nouns as possible interpretations
# (it wouldn't be correct to capitalize verbs, adjectives, etc.)
m = [mm for mm in m if mm.ordfl in {"kk", "kvk", "hk"}]
m = BIN_Db.prefix_meanings(m, prefix)
if not m and lower_w.startswith('ó'):
# Check whether an adjective without the 'ó' prefix is found in BÍN
# (i.e. create 'óhefðbundinn' from 'hefðbundinn')
suffix = lower_w[1:]
if suffix:
om = lookup(suffix)
if om:
m = [
BIN_Meaning("ó" + r.stofn, r.utg, r.ordfl, r.fl,
"ó" + r.ordmynd, r.beyging) for r in om
if r.ordfl == "lo"
]
if not m and auto_uppercase and w.islower():
# If no meaning found and we're auto-uppercasing,
# convert this to upper case (could very well be a name
# of a person or entity)
w = w.capitalize()
# noinspection PyRedundantParentheses
return (w, m)
def check_legality(self, state):
""" Check whether this move is legal on the board """
# Must cover at least one square
if len(self._covers) < 1:
return Error.NULL_MOVE
if len(self._covers) > Rack.MAX_TILES:
return Error.TOO_MANY_TILES_PLAYED
if state.is_game_over():
return Error.GAME_OVER
rack = state.player_rack()
board = state.board()
row = 0
col = 0
horiz = True
vert = True
first = True
# All tiles played must be in the rack
played = u''.join([c.tile for c in self._covers])
if not rack.contains(played):
return Error.TILE_NOT_IN_RACK
# The tiles covered by the move must be purely horizontal or purely vertical
for c in self._covers:
if first:
row = c.row
col = c.col
first = False
else:
if c.row != row:
horiz = False
if c.col != col:
vert = False
if (not horiz) and (not vert):
# Spread all over: not legal
return Error.DISJOINT
# If only one cover, use the orientation of the longest word formed
if len(self._covers) == 1:
# In the case of a tied length, we use horizontal
self._horizontal = len(board.letters_left(row, col)) + len(board.letters_right(row, col)) >= \
len(board.letters_above(row, col)) + len(board.letters_below(row, col))
horiz = self._horizontal
vert = not horiz
# The move is purely horizontal or vertical
if horiz:
self._covers.sort(key = lambda x: x.col) # Sort in ascending column order
self._horizontal = True
else:
self._covers.sort(key = lambda x: x.row) # Sort in ascending row order
self._horizontal = False
# Check whether eventual missing squares in the move sequence are already covered
row = 0
col = 0
first = True
for c in self._covers:
if board.is_covered(c.row, c.col):
# We already have a tile in the square: illegal play
return Error.SQUARE_ALREADY_OCCUPIED
# If there is a gap between this cover and the last one,
# make sure all intermediate squares are covered
if first:
self._row = c.row
self._col = c.col
first = False
else:
if horiz:
# Horizontal: check squares within row
for ix in range(col + 1, c.col):
if not board.is_covered(c.row, ix):
# Found gap: illegal play
return Error.HAS_GAP
else:
# assert vert
# Vertical: check squares within column
for ix in range(row + 1, c.row):
if not board.is_covered(ix, c.col):
# Found gap: illegal play
return Error.HAS_GAP
row = c.row
col = c.col
# Find the start and end of the word that is being formed, including
# tiles aready on the board
if horiz:
# Look for the beginning
while self._col > 0 and board.is_covered(self._row, self._col - 1):
self._col -= 1
# Look for the end
while col + 1 < Board.SIZE and board.is_covered(self._row, col + 1):
col += 1
# Now we know the length
self._numletters = col - self._col + 1
else:
# Look for the beginning
while self._row > 0 and board.is_covered(self._row - 1, self._col):
self._row -= 1
# Look for the end
while row + 1 < Board.SIZE and board.is_covered(row + 1, self._col):
row += 1
# Now we know the length
self._numletters = row - self._row + 1
# Assemble the resulting word
self._word = u''
self._tiles = u''
cix = 0
for ix in range(self._numletters):
def add(cix):
ltr = self._covers[cix].letter
tile = self._covers[cix].tile
self._word += ltr
self._tiles += tile + (ltr if tile == u'?' else u'')
if horiz:
if cix < len(self._covers) and self._col + ix == self._covers[cix].col:
# This is one of the new letters
add(cix)
cix += 1
else:
# This is a letter that was already on the board
ltr = board.letter_at(self._row, self._col + ix)
self._word += ltr
self._tiles += ltr
else:
if cix < len(self._covers) and self._row + ix == self._covers[cix].row:
# This is one of the new letters
add(cix)
cix += 1
else:
# This is a letter that was already on the board
ltr = board.letter_at(self._row + ix, self._col)
self._word += ltr
self._tiles += ltr
# Check whether the word is in the dictionary
if self._word not in Wordbase.dawg():
# print(u"Word '{0}' not found in dictionary".format(self._word))
return (Error.WORD_NOT_IN_DICTIONARY, self._word)
# Check that the play is adjacent to some previously placed tile
# (unless this is the first move, i.e. the board is empty)
if board.is_empty():
# Must go through the center square
center = False
for c in self._covers:
if c.row == Board.SIZE // 2 and c.col == Board.SIZE // 2:
center = True
break
if not center:
return Error.FIRST_MOVE_NOT_IN_CENTER
else:
# Must be adjacent to something already on the board
if not any([board.has_adjacent(c.row, c.col) for c in self._covers]):
return Error.NOT_ADJACENT
# Check all cross words formed by the new tiles
for c in self._covers:
if self._horizontal:
cross = board.letters_above(c.row, c.col) + c.letter + board.letters_below(c.row, c.col)
else:
cross = board.letters_left(c.row, c.col) + c.letter + board.letters_right(c.row, c.col)
if len(cross) > 1 and cross not in Wordbase.dawg():
return (Error.CROSS_WORD_NOT_IN_DICTIONARY, cross)
# All checks pass: the play is legal
return Error.LEGAL
class Axis:
""" Represents a one-dimensional axis on the board, either
horizontal or vertical. This is used to find legal moves
for an AutoPlayer.
"""
DAWG = Wordbase.dawg()
def __init__(self, autoplayer, index, horizontal):
self._autoplayer = autoplayer
self._sq = [None] * Board.SIZE
for i in range(Board.SIZE):
self._sq[i] = Square()
self._index = index
self._horizontal = horizontal
self._rack = autoplayer.rack()
# Bit pattern representing empty squares on this axis
self._empty_bits = 0
def is_horizontal(self):
""" Is this a horizontal (row) axis? """
return self._horizontal
def is_vertical(self):
""" Is this a vertical (column) axis? """
return not self._horizontal
def coordinate_of(self, index):
""" Return the co-ordinate on the board of a square within this axis """
return (self._index, index) if self._horizontal else (index,
self._index)
def coordinate_step(self):
""" How to move along this axis on the board, (row,col) """
return (0, 1) if self._horizontal else (1, 0)
def letter_at(self, index):
""" Return the letter at the index """
return self._sq[index].letter()
def is_open(self, index):
""" Is the square at the index open (i.e. can a tile be placed there?) """
return self._sq[index].is_open()
def is_open_for(self, index, letter):
""" Is the square at the index open for this letter? """
return self._sq[index].is_open_for(letter)
def is_empty(self, index):
""" Is the square at the index empty? """
return bool(self._empty_bits & (1 << index))
def mark_anchor(self, index):
""" Force the indicated square to be an anchor. Used in first move
to mark the center square. """
self._sq[index].mark_anchor()
def init_crosschecks(self):
""" Calculate and return a list of cross-check bit patterns for the indicated axis """
# The cross-check set is the set of letters that can appear in a square
# and make cross words (above/left and/or below/right of the square) valid
board = self._autoplayer.board()
# Prepare to visit all squares on the axis
x, y = self.coordinate_of(0)
xd, yd = self.coordinate_step()
# Fetch the default cross-check bits, which depend on the rack.
# If the rack contains a wildcard (blank tile), the default cc set
# contains all letters in the Alphabet. Otherwise, it contains the
# letters in the rack.
all_cc = self._autoplayer.rack_bit_pattern()
# Go through the open squares and calculate their cross-checks
for ix in range(Board.SIZE):
cc = all_cc # Start with the default cross-check set
if not board.is_covered(x, y):
if self.is_horizontal():
above = board.letters_above(x, y)
below = board.letters_below(x, y)
else:
above = board.letters_left(x, y)
below = board.letters_right(x, y)
query = above or u''
query += u'?'
if below:
query += below
if len(query) > 1:
# Nontrivial cross-check: Query the word database for words that fit this pattern
matches = self.DAWG.find_matches(
query, sort=False) # Don't need a sorted result
bits = 0
if matches:
cix = len(above) if above else 0
# Note the set of allowed letters here
bits = Alphabet.bit_pattern(
[wrd[cix] for wrd in matches])
# Reduce the cross-check set by intersecting it with the allowed set.
# If the cross-check set and the rack have nothing in common, this
# will lead to the square being marked as closed, which saves
# calculation later on
cc &= bits
# Initialize the square
self._sq[ix].init(self._autoplayer, x, y, cc)
# Keep track of empty squares within the axis in a bit pattern for speed
if self._sq[ix].is_empty():
self._empty_bits |= (1 << ix)
x += xd
y += yd
def _gen_moves_from_anchor(self, index, maxleft, lpn):
""" Find valid moves emanating (on the left and right) from this anchor """
if maxleft == 0 and index > 0 and not self.is_empty(index - 1):
# We have a left part already on the board: try to complete it
leftpart = u''
ix = index
while ix > 0 and not self.is_empty(ix - 1):
leftpart = self._sq[ix - 1]._letter + leftpart
ix -= 1
# Use the ExtendRightNavigator to find valid words with this left part
nav = LeftFindNavigator(leftpart)
self.DAWG.navigate(nav)
ns = nav.state()
if ns is not None:
# We found a matching prefix in the graph
_, prefix, nextnode = ns
# assert matched == leftpart
nav = ExtendRightNavigator(self, index, self._rack)
self.DAWG.resume_navigation(nav, prefix, nextnode, leftpart)
return
# We are not completing an existing left part
# Begin by extending an empty prefix to the right, i.e. placing
# tiles on the anchor square itself and to its right
nav = ExtendRightNavigator(self, index, self._rack)
self.DAWG.navigate(nav)
if maxleft > 0 and lpn is not None:
# Follow this by an effort to permute left prefixes into the open space
# to the left of the anchor square
for leftlen in range(1, maxleft + 1):
lplist = lpn.leftparts(leftlen)
if lplist is not None:
for leftpart, rackleave, prefix, nextnode in lplist:
nav = ExtendRightNavigator(self, index, rackleave)
self.DAWG.resume_navigation(nav, prefix, nextnode,
leftpart)
def generate_moves(self, lpn):
""" Find all valid moves on this axis by attempting to place tiles
at and around all anchor squares """
last_anchor = -1
lenrack = len(self._rack)
for i in range(Board.SIZE):
if self._sq[i].is_anchor():
# Count the consecutive open, non-anchor squares on the left of the anchor
opensq = 0
left = i
while left > 0 and left > (last_anchor +
1) and self._sq[left - 1].is_open():
opensq += 1
left -= 1
# We have a maximum left part length of min(opensq, lenrack-1) as the anchor
# square itself must always be filled from the rack
self._gen_moves_from_anchor(i, min(opensq, lenrack - 1), lpn)
last_anchor = i
def check_legality(self, state):
""" Check whether this move is legal on the board """
# Must cover at least one square
if len(self._covers) < 1:
return Error.NULL_MOVE
if len(self._covers) > Rack.MAX_TILES:
return Error.TOO_MANY_TILES_PLAYED
if state.is_game_over():
return Error.GAME_OVER
rack = state.player_rack()
board = state.board()
row = 0
col = 0
horiz = True
vert = True
first = True
# All tiles played must be in the rack
played = u''.join([c.tile for c in self._covers])
if not rack.contains(played):
return Error.TILE_NOT_IN_RACK
# The tiles covered by the move must be purely horizontal or purely vertical
for c in self._covers:
if first:
row = c.row
col = c.col
first = False
else:
if c.row != row:
horiz = False
if c.col != col:
vert = False
if (not horiz) and (not vert):
# Spread all over: not legal
return Error.DISJOINT
# If only one cover, use the orientation of the longest word formed
if len(self._covers) == 1:
# In the case of a tied length, we use horizontal
self._horizontal = len(board.letters_left(row, col)) + len(board.letters_right(row, col)) >= \
len(board.letters_above(row, col)) + len(board.letters_below(row, col))
horiz = self._horizontal
# The move is purely horizontal or vertical
if horiz:
self._covers.sort(
key=lambda x: x.col) # Sort in ascending column order
self._horizontal = True
else:
self._covers.sort(
key=lambda x: x.row) # Sort in ascending row order
self._horizontal = False
# Check whether eventual missing squares in the move sequence are already covered
row = 0
col = 0
first = True
for c in self._covers:
if board.is_covered(c.row, c.col):
# We already have a tile in the square: illegal play
return Error.SQUARE_ALREADY_OCCUPIED
# If there is a gap between this cover and the last one,
# make sure all intermediate squares are covered
if first:
self._row = c.row
self._col = c.col
first = False
else:
if horiz:
# Horizontal: check squares within row
for ix in range(col + 1, c.col):
if not board.is_covered(c.row, ix):
# Found gap: illegal play
return Error.HAS_GAP
else:
# Vertical: check squares within column
for ix in range(row + 1, c.row):
if not board.is_covered(ix, c.col):
# Found gap: illegal play
return Error.HAS_GAP
row = c.row
col = c.col
# Find the start and end of the word that is being formed, including
# tiles aready on the board
if horiz:
# Look for the beginning
while self._col > 0 and board.is_covered(self._row, self._col - 1):
self._col -= 1
# Look for the end
while col + 1 < Board.SIZE and board.is_covered(
self._row, col + 1):
col += 1
# Now we know the length
self._numletters = col - self._col + 1
else:
# Look for the beginning
while self._row > 0 and board.is_covered(self._row - 1, self._col):
self._row -= 1
# Look for the end
while row + 1 < Board.SIZE and board.is_covered(
row + 1, self._col):
row += 1
# Now we know the length
self._numletters = row - self._row + 1
# Assemble the resulting word
self._word = u''
self._tiles = u''
cix = 0
for ix in range(self._numletters):
def add(cix):
ltr = self._covers[cix].letter
tile = self._covers[cix].tile
self._word += ltr
self._tiles += tile + (ltr if tile == u'?' else u'')
if horiz:
if cix < len(self._covers
) and self._col + ix == self._covers[cix].col:
# This is one of the new letters
add(cix)
cix += 1
else:
# This is a letter that was already on the board
ltr = board.letter_at(self._row, self._col + ix)
self._word += ltr
self._tiles += ltr
else:
if cix < len(self._covers
) and self._row + ix == self._covers[cix].row:
# This is one of the new letters
add(cix)
cix += 1
else:
# This is a letter that was already on the board
ltr = board.letter_at(self._row + ix, self._col)
self._word += ltr
self._tiles += ltr
# Check whether the word is in the dictionary
if self._word not in Wordbase.dawg():
# print(u"Word '{0}' not found in dictionary".format(self._word))
return (Error.WORD_NOT_IN_DICTIONARY, self._word)
# Check that the play is adjacent to some previously placed tile
# (unless this is the first move, i.e. the board is empty)
if board.is_empty():
# Must go through the center square
center = False
for c in self._covers:
if c.row == Board.SIZE // 2 and c.col == Board.SIZE // 2:
center = True
break
if not center:
return Error.FIRST_MOVE_NOT_IN_CENTER
else:
# Must be adjacent to something already on the board
if not any(
[board.has_adjacent(c.row, c.col) for c in self._covers]):
return Error.NOT_ADJACENT
# Check all cross words formed by the new tiles
for c in self._covers:
if self._horizontal:
cross = board.letters_above(
c.row, c.col) + c.letter + board.letters_below(
c.row, c.col)
else:
cross = board.letters_left(
c.row, c.col) + c.letter + board.letters_right(
c.row, c.col)
if len(cross) > 1 and cross not in Wordbase.dawg():
return (Error.CROSS_WORD_NOT_IN_DICTIONARY, cross)
# All checks pass: the play is legal
return Error.LEGAL
