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
|
%token TK_COMMENT TK_IDENTIFIER TK_NUMBER
%token TK_OPERATOR TK_STRING
%token TK_INDENT TK_DEDENT TK_NEWLINE
%token KR_and KR_assert KR_break KR_class KR_continue KR_def
%token KR_del KR_elif KR_else KR_except KR_exec KR_finally
%token KR_for KR_from KR_global KR_if KR_import KR_in KR_is
%token KR_lambda KR_not KR_or KR_pass KR_print KR_raise
%token KR_return KR_try KR_while KR_yield
%start file_input
%{
#include "elx.h"
void yyerror(const char *msg);
int yylex(void);
/* ### should come from an elx-python.h or something */
void issue_token(char which);
%}
%export {
/* the main parsing function */
int yyparse(void);
/* need to define the 'not found' in addition to the regular keywords */
#define KR__not_found 0
}
%%
file_input: (TK_NEWLINE | stmt)*
NAME: TK_IDENTIFIER
funcdef: KR_def NAME { issue_token(ELX_LOCAL_FDEF); } parameters ':' suite
parameters: '(' [varargslist] ')'
varargslist: paramdef (',' paramdef)* [',' [varargsdef]]
| varargsdef
;
/* the TK_OPERATOR represents '*' or '**' */
varargsdef: TK_OPERATOR NAME [',' TK_OPERATOR NAME]
paramdef: fpdef [TK_OPERATOR test]
fpdef: NAME | '(' fplist ')'
fplist: fpdef (',' fpdef)* [',']
stmt: simple_stmt | compound_stmt
simple_stmt: small_stmt (';' small_stmt)* [';'] TK_NEWLINE
small_stmt: expr_stmt | print_stmt | raise_stmt
| import_stmt | global_stmt | exec_stmt | assert_stmt
| KR_del exprlist
| KR_pass
| KR_break
| KR_continue
| KR_return [testlist]
| KR_yield testlist
;
/* expr_stmt is normally assignment, which we get thru TK_OPERATOR in 'expr' */
expr_stmt: testlist
/* a print normally allows '>> test'; since that is a TK_OPERATOR, we
get it as part of 'factor'. this rule also allows for a trailing
comma in '>> test,' which the normal print doesn't */
print_stmt: KR_print [test (',' test)* [',']]
raise_stmt: KR_raise [test [',' test [',' test]]]
/* the TK_OPERATOR represents '*' */
import_stmt: KR_import dotted_as_name (',' dotted_as_name)*
| KR_from dotted_name KR_import (TK_OPERATOR | import_as_name (',' import_as_name)*)
import_as_name: NAME [NAME NAME]
dotted_as_name: dotted_name [NAME NAME]
dotted_name: NAME ('.' NAME)*
global_stmt: KR_global NAME (',' NAME)*
exec_stmt: KR_exec expr [KR_in test [',' test]]
assert_stmt: KR_assert test [',' test]
compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | funcdef | classdef
if_stmt: KR_if test ':' suite (KR_elif test ':' suite)* [KR_else ':' suite]
while_stmt: KR_while test ':' suite [KR_else ':' suite]
for_stmt: KR_for exprlist KR_in testlist ':' suite [KR_else ':' suite]
try_stmt: KR_try ':' suite (except_clause ':' suite)+
[KR_else ':' suite] | KR_try ':' suite KR_finally ':' suite
/* NB compile.c makes sure that the default except clause is last */
except_clause: KR_except [test [',' test]]
suite: simple_stmt | TK_NEWLINE TK_INDENT stmt+ TK_DEDENT
test: test_factor (test_op test_factor | KR_is [KR_not] factor)*
[TK_OPERATOR lambdef] | lambdef
test_op: bin_op | KR_in
test_factor: KR_not* factor
expr: factor (expr_op factor)*
expr_op: bin_op | KR_is [KR_not]
factor: TK_OPERATOR* atom trailer*
bin_op: TK_OPERATOR | KR_or | KR_and | KR_not KR_in
atom: '(' [testlist] ')' | '[' [listmaker] ']' | '{' [dictmaker] '}'
| '`' testlist_no_trailing '`' | TK_IDENTIFIER | TK_NUMBER | TK_STRING+
listmaker: test ( list_for | (',' test)* [','] )
lambdef: KR_lambda [varargslist] ':' test
trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
subscriptlist: subscript (',' subscript)* [',']
subscript: '.' '.' '.' | test | [test] ':' [test] [sliceop]
sliceop: ':' [test]
exprlist: expr (',' expr)* [',']
testlist: test (',' test)* [',']
testlist_no_trailing: test (',' test)*
testlist_safe: test [(',' test)+ [',']] /* doesn't match: test, */
dictmaker: test ':' test (',' test ':' test)* [',']
classdef: KR_class NAME ['(' testlist ')'] ':' suite
/* arguments are normally 'keyword = test; since '=' is TK_OPERATOR, we
match keyword arguments as part of 'test' (in 'expr').
the vararg portion is normally '* test' or '** test'; since '*' and
'**' are TK_OPERATOR, we match varargs as part of 'test' (in
'factor')
thus, all argument forms are simply 'test'
varargs does not normally allow a trailing comma, but we can
simplify things and allow a match
*/
arglist: test (',' test)* [',']
list_iter: list_for | list_if
list_for: KR_for exprlist KR_in testlist_safe [list_iter]
list_if: KR_if test [list_iter]
|
