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
182
183
184
185
186
187
|
// Python 3 grammar for Lark
// NOTE: Work in progress!!! (XXX TODO)
// This grammar should parse all python 3.x code successfully,
// but the resulting parse-tree is still not well-organized.
// Adapted from: https://docs.python.org/3/reference/grammar.html
// Adapted by: Erez Shinan
// Start symbols for the grammar:
// single_input is a single interactive statement;
// file_input is a module or sequence of commands read from an input file;
// eval_input is the input for the eval() functions.
// NB: compound_stmt in single_input is followed by extra NEWLINE!
single_input: _NEWLINE | simple_stmt | compound_stmt _NEWLINE
file_input: (_NEWLINE | stmt)*
eval_input: testlist _NEWLINE*
decorator: "@" dotted_name [ "(" [arguments] ")" ] _NEWLINE
decorators: decorator+
decorated: decorators (classdef | funcdef | async_funcdef)
async_funcdef: "async" funcdef
funcdef: "def" NAME "(" parameters? ")" ["->" test] ":" suite
parameters: paramvalue ("," paramvalue)* ["," [ starparams | kwparams]]
| starparams
| kwparams
starparams: "*" typedparam? ("," paramvalue)* ["," kwparams]
kwparams: "**" typedparam
?paramvalue: typedparam ["=" test]
?typedparam: NAME [":" test]
varargslist: (vfpdef ["=" test] ("," vfpdef ["=" test])* ["," [ "*" [vfpdef] ("," vfpdef ["=" test])* ["," ["**" vfpdef [","]]] | "**" vfpdef [","]]]
| "*" [vfpdef] ("," vfpdef ["=" test])* ["," ["**" vfpdef [","]]]
| "**" vfpdef [","])
vfpdef: NAME
?stmt: simple_stmt | compound_stmt
?simple_stmt: small_stmt (";" small_stmt)* [";"] _NEWLINE
?small_stmt: (expr_stmt | del_stmt | pass_stmt | flow_stmt | import_stmt | global_stmt | nonlocal_stmt | assert_stmt)
?expr_stmt: testlist_star_expr (annassign | augassign (yield_expr|testlist)
| ("=" (yield_expr|testlist_star_expr))*)
annassign: ":" test ["=" test]
?testlist_star_expr: (test|star_expr) ("," (test|star_expr))* [","]
!augassign: ("+=" | "-=" | "*=" | "@=" | "/=" | "%=" | "&=" | "|=" | "^=" | "<<=" | ">>=" | "**=" | "//=")
// For normal and annotated assignments, additional restrictions enforced by the interpreter
del_stmt: "del" exprlist
pass_stmt: "pass"
?flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt | yield_stmt
break_stmt: "break"
continue_stmt: "continue"
return_stmt: "return" [testlist]
yield_stmt: yield_expr
raise_stmt: "raise" [test ["from" test]]
import_stmt: import_name | import_from
import_name: "import" dotted_as_names
// note below: the ("." | "...") is necessary because "..." is tokenized as ELLIPSIS
import_from: "from" (dots? dotted_name | dots) "import" ("*" | "(" import_as_names ")" | import_as_names)
!dots: "."+
import_as_name: NAME ["as" NAME]
dotted_as_name: dotted_name ["as" NAME]
import_as_names: import_as_name ("," import_as_name)* [","]
dotted_as_names: dotted_as_name ("," dotted_as_name)*
dotted_name: NAME ("." NAME)*
global_stmt: "global" NAME ("," NAME)*
nonlocal_stmt: "nonlocal" NAME ("," NAME)*
assert_stmt: "assert" test ["," test]
compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated | async_stmt
async_stmt: "async" (funcdef | with_stmt | for_stmt)
if_stmt: "if" test ":" suite ("elif" test ":" suite)* ["else" ":" suite]
while_stmt: "while" test ":" suite ["else" ":" suite]
for_stmt: "for" exprlist "in" testlist ":" suite ["else" ":" suite]
try_stmt: ("try" ":" suite ((except_clause ":" suite)+ ["else" ":" suite] ["finally" ":" suite] | "finally" ":" suite))
with_stmt: "with" with_item ("," with_item)* ":" suite
with_item: test ["as" expr]
// NB compile.c makes sure that the default except clause is last
except_clause: "except" [test ["as" NAME]]
suite: simple_stmt | _NEWLINE _INDENT stmt+ _DEDENT
?test: or_test ("if" or_test "else" test)? | lambdef
?test_nocond: or_test | lambdef_nocond
lambdef: "lambda" [varargslist] ":" test
lambdef_nocond: "lambda" [varargslist] ":" test_nocond
?or_test: and_test ("or" and_test)*
?and_test: not_test ("and" not_test)*
?not_test: "not" not_test -> not
| comparison
?comparison: expr (_comp_op expr)*
star_expr: "*" expr
?expr: xor_expr ("|" xor_expr)*
?xor_expr: and_expr ("^" and_expr)*
?and_expr: shift_expr ("&" shift_expr)*
?shift_expr: arith_expr (_shift_op arith_expr)*
?arith_expr: term (_add_op term)*
?term: factor (_mul_op factor)*
?factor: _factor_op factor | power
!_factor_op: "+"|"-"|"~"
!_add_op: "+"|"-"
!_shift_op: "<<"|">>"
!_mul_op: "*"|"@"|"/"|"%"|"//"
// <> isn't actually a valid comparison operator in Python. It's here for the
// sake of a __future__ import described in PEP 401 (which really works :-)
!_comp_op: "<"|">"|"=="|">="|"<="|"<>"|"!="|"in"|"not" "in"|"is"|"is" "not"
?power: await_expr ("**" factor)?
?await_expr: AWAIT? atom_expr
AWAIT: "await"
?atom_expr: atom_expr "(" [arguments] ")" -> funccall
| atom_expr "[" subscriptlist "]" -> getitem
| atom_expr "." NAME -> getattr
| atom
?atom: "(" [yield_expr|testlist_comp] ")" -> tuple
| "[" [testlist_comp] "]" -> list
| "{" [dictorsetmaker] "}" -> dict
| NAME -> var
| number | string+
| "(" test ")"
| "..." -> ellipsis
| "None" -> const_none
| "True" -> const_true
| "False" -> const_false
?testlist_comp: (test|star_expr) [comp_for | ("," (test|star_expr))+ [","] | ","]
subscriptlist: subscript ("," subscript)* [","]
subscript: test | [test] ":" [test] [sliceop]
sliceop: ":" [test]
exprlist: (expr|star_expr) ("," (expr|star_expr))* [","]
testlist: test ("," test)* [","]
dictorsetmaker: ( ((test ":" test | "**" expr) (comp_for | ("," (test ":" test | "**" expr))* [","])) | ((test | star_expr) (comp_for | ("," (test | star_expr))* [","])) )
classdef: "class" NAME ["(" [arguments] ")"] ":" suite
arguments: argvalue ("," argvalue)* ("," [ starargs | kwargs])?
| starargs
| kwargs
| test comp_for
starargs: "*" test ("," "*" test)* ("," argvalue)* ["," kwargs]
kwargs: "**" test
?argvalue: test ("=" test)?
comp_iter: comp_for | comp_if | async_for
async_for: "async" "for" exprlist "in" or_test [comp_iter]
comp_for: "for" exprlist "in" or_test [comp_iter]
comp_if: "if" test_nocond [comp_iter]
// not used in grammar, but may appear in "node" passed from Parser to Compiler
encoding_decl: NAME
yield_expr: "yield" [yield_arg]
yield_arg: "from" test | testlist
number: DEC_NUMBER | HEX_NUMBER | BIN_NUMBER | OCT_NUMBER | FLOAT_NUMBER | IMAG_NUMBER
string: STRING | LONG_STRING
// Tokens
NAME: /[a-zA-Z_]\w*/
COMMENT: /#[^\n]*/
_NEWLINE: ( /\r?\n[\t ]*/ | COMMENT )+
STRING : /[ubf]?r?("(?!"").*?(?<!\\)(\\\\)*?"|'(?!'').*?(?<!\\)(\\\\)*?')/i
LONG_STRING: /[ubf]?r?(""".*?(?<!\\)(\\\\)*?"""|'''.*?(?<!\\)(\\\\)*?''')/is
DEC_NUMBER: /0|[1-9]\d*/i
HEX_NUMBER.2: /0x[\da-f]*/i
OCT_NUMBER.2: /0o[0-7]*/i
BIN_NUMBER.2 : /0b[0-1]*/i
FLOAT_NUMBER.2: /((\d+\.\d*|\.\d+)(e[-+]?\d+)?|\d+(e[-+]?\d+))/i
IMAG_NUMBER.2: /\d+j/i | FLOAT_NUMBER "j"i
%ignore /[\t \f]+/ // WS
%ignore /\\[\t \f]*\r?\n/ // LINE_CONT
%ignore COMMENT
%declare _INDENT _DEDENT
|
