1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
from enum import Enum
class LitType(Enum):
TAGGLOB = 2
TITLEGLOB = 3
TAG = 9
class TokType(Enum):
OR = 0
NOT = 1
EOF = 5
AND = 6
OPEN = 7
CLOSE = 8
def classify_head(l):
if len(l) == 0:
return (TokType.EOF, None)
s = l[0]
if s == "OR":
return (TokType.OR,None)
elif s == "NOT":
return (TokType.NOT,None)
elif s == "[":
return (TokType.OPEN,None)
elif s == "]":
return (TokType.CLOSE,None)
elif s[:2] == "~~":
return (LitType.TAGGLOB, s[2:])
elif s[:2] == "~-":
return (LitType.TITLEGLOB, s[2:])
else:
return (LitType.TAG, s)
class Atom:
def __str__(self):
return f'({self.op} "{self.v}")'
def __init__(self, op, v):
self.op = op
self.v = v
class ParseTree:
def push(self, pt):
self.l.append(pt)
def __str__(self):
s = f'({self.op}'
for i in self.l:
s = s + ' ' + str(i)
return s + ')'
def __init__(self, op, l):
self.op = op
self.l = l
def query_lit(alist, lit, isNot):
if lit.op == LitType.TAGGLOB:
qr = f"""tag in (SELECT id FROM tags
WHERE name GLOB ?{len(alist)})"""
elif lit.op == LitType.TITLEGLOB:
qr = f"""card in (SELECT id FROM cards
WHERE name GLOB ?{len(alist)})"""
elif lit.op == LitType.TAG:
qr = f"""tag in (SELECT id FROM tags
WHERE name = ?{len(alist)} LIMIT 1)"""
else:
raise ParseError
alist.append(lit.v)
if isNot:
qr = f"NOT ({qr})"
return f"SELECT card FROM tagmap WHERE {qr}"
# Returns bl,xpr where bl = True when xpr is for a literal
def build(alist, pt):
if pt.op == TokType.OR:
conn = "UNION"
elif pt.op == TokType.AND:
conn = "INTERSECTION"
elif pt.op == TokType.NOT:
return True,query_lit(alist, pt.l[0], True)
elif pt.op in LitType:
return True,query_lit(alist, pt, False)
else:
raise ParseError
v, r = build(alist, pt.l[0])
if not v:
r = f"SELECT card FROM ({r})"
for i in pt.l[1:]:
v,exr = build(alist, i)
if not v:
exr = f"SELECT card FROM f({exr})"
r = f"{r} {conn} {exr}"
return False,r
def encapsulate(pt, op):
if pt.op != op:
pt = ParseTree(op, [pt])
return pt
def demorgan(pt):
if pt.op in LitType:
return ParseTree(TokType.NOT, [pt])
elif pt.op == TokType.NOT:
return pt.l[0]
elif pt.op == TokType.OR:
pt.op = TokType.AND
elif pt.op == TokType.AND:
pt.op = TokType.OR
else:
raise ParseError
pt.l = [demorgan(x) for x in pt.l]
return pt
"""
The parser is implemented like
e1 ::= e2 ("OR" e2)*;
e2 ::= e3*;
e3 ::= "NOT"? e4;
e4 ::= TAG | "[" e1 "]";
"""
class ParseError(Exception):
pass
def e4(lits, l):
typ,s = classify_head(l)
if typ == TokType.OPEN:
pt,l = e1(lits, l[1:])
typ,_ = classify_head(l)
if typ != TokType.CLOSE:
raise ParseError
return pt,l[1:]
elif typ in LitType:
lits.add((typ, s))
return Atom(typ, s), l[1:]
else:
raise ParseError
def e3(lits, l):
typ,_ = classify_head(l)
if typ == TokType.NOT:
pt,l = e4(lits, l[1:])
return demorgan(pt), l
return e4(lits, l)
def e2(lits, l):
pt,l = e3(lits, l)
try:
while True:
pt2,l = e3(lits, l)
pt = encapsulate(pt, TokType.AND)
pt.push(pt2)
except ParseError:
pass
return pt,l
def e1(lits, l):
pt,l = e2(lits, l)
typ,_ = classify_head(l)
try:
while typ == TokType.OR:
pt2,l = e2(lits, l[1:])
pt = encapsulate(pt, TokType.OR)
pt.push(pt2)
typ,_ = classify_head(l)
except ParseError:
pass
return pt,l
def parse(l):
lits = set()
x,l = e1(lits, l)
if l != []:
raise ParseError
return x,lits
|
