def test_basic(self):
p = Lark("""
start: "a" "b" "c" "d"
%ignore " "
""")
res = list(p.lex("abc cba dd"))
assert res == list('abccbadd')
res = list(p.lex("abc cba dd", dont_ignore=True))
assert res == list('abc cba dd')
def main():
fin = open("grammar.lark")
grammar = fin.read()
fin.close()
parser = Lark(grammar, parser="lalr")
#parser = Lark ( grammar, parser = "lalr", lexer = "contextual" )
#parser = Lark ( grammar )
count = 1
testfile = "./test%s.txt" % count
while os.path.exists(testfile):
print("\n\n--- Parsing file: %s ---\n" % testfile)
fin = open(testfile)
try:
buf = fin.read()
print(buf)
# Debug lexer
print("Lexer: ", [x for x in parser.lex(buf)], "\n")
tree = parser.parse(buf)
print(tree, "\n\n")
print(tree.pretty())
finally:
fin.close()
count += 1
testfile = "./test%s.txt" % count
class LexerJson(QsciLexerCustom):
def __init__(self, parent=None):
super().__init__(parent)
self.create_parser()
self.create_styles()
def create_styles(self):
deeppink = QColor(249, 38, 114)
khaki = QColor(230, 219, 116)
mediumpurple = QColor(174, 129, 255)
mediumturquoise = QColor(81, 217, 205)
yellowgreen = QColor(166, 226, 46)
lightcyan = QColor(213, 248, 232)
darkslategrey = QColor(39, 40, 34)
styles = {
0: mediumturquoise,
1: mediumpurple,
2: yellowgreen,
3: deeppink,
4: khaki,
5: lightcyan
}
for style, color in styles.items():
self.setColor(color, style)
self.setPaper(darkslategrey, style)
self.setFont(self.parent().font(), style)
self.token_styles = {
"COLON": 5,
"COMMA": 5,
"LBRACE": 5,
"LSQB": 5,
"RBRACE": 5,
"RSQB": 5,
"FALSE": 0,
"NULL": 0,
"TRUE": 0,
"STRING": 4,
"NUMBER": 1,
}
def create_parser(self):
grammar = '''
anons: ":" "{" "}" "," "[" "]"
TRUE: "true"
FALSE: "false"
NULL: "NULL"
%import common.ESCAPED_STRING -> STRING
%import common.SIGNED_NUMBER -> NUMBER
%import common.WS
%ignore WS
'''
self.lark = Lark(grammar, parser=None, lexer='standard')
# All tokens: print([t.name for t in self.lark.parser.lexer.tokens])
def defaultPaper(self, style):
return QColor(39, 40, 34)
def language(self):
return "Json"
def description(self, style):
return {v: k for k, v in self.token_styles.items()}.get(style, "")
def styleText(self, start, end):
self.startStyling(start)
text = self.parent().text()[start:end]
last_pos = 0
try:
for token in self.lark.lex(text):
ws_len = token.pos_in_stream - last_pos
if ws_len:
self.setStyling(ws_len, 0) # whitespace
token_len = len(bytearray(token, "utf-8"))
self.setStyling(token_len,
self.token_styles.get(token.type, 0))
last_pos = token.pos_in_stream + token_len
except Exception as e:
print(e)
lang_file = open("calculator.lark")
calc_parser = Lark(lang_file.read(), start='chain')
values = [10, '+', 3, '*', 2, '^', 5, '+', 2]
#text = '10 + 3 * 2 ^ 5 + 2'
text = '9 ^ 3 ^ 2 ^ 2'
# for tk in calc_parser.lex('10 + 2 + 3'):
# print(repr(tk))
tree = calc_parser.parse(text)
print(tree.pretty())
lexed = []
for tk in calc_parser.lex(text):
lexed.append((tk[0:], tk.type))
while len(lexed) > 1:
print(lexed)
higher = find_highest_precedence(lexed)
idx = lexed.index(higher)
res = evaluate(lexed[idx - 1][0], lexed[idx][0], lexed[idx + 1][0])
lexed.insert(idx - 1, res)
for i in range(3):
lexed.pop(idx)
print(lexed[0][0])
