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
|
%glr-parser
%pure-parser
%locations
%error-verbose
%parse-param { yyscan_t scanner }
%parse-param { void * data }
%lex-param { yyscan_t scanner }
%{
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <aterm2.h>
#include "parser-tab.h"
#include "lexer-tab.h"
typedef ATerm Expr;
typedef ATerm Pos;
#include "nixexpr-ast.hh"
void setParseResult(void * data, ATerm t);
void parseError(void * data, char * error, int line, int column);
ATerm absParsedPath(void * data, ATerm t);
ATerm fixAttrs(int recursive, ATermList as);
const char * getPath(void * data);
void yyerror(YYLTYPE * loc, yyscan_t scanner, void * data, char * s)
{
parseError(data, s, loc->first_line, loc->first_column);
}
ATerm toATerm(const char * s)
{
return (ATerm) ATmakeAppl0(ATmakeAFun((char *) s, 0, ATtrue));
}
static Pos makeCurPos(YYLTYPE * loc, void * data)
{
return makePos(toATerm(getPath(data)),
loc->first_line, loc->first_column);
}
#define CUR_POS makeCurPos(yylocp, data)
%}
%union {
ATerm t;
ATermList ts;
}
%type <t> start expr expr_function expr_if expr_op
%type <t> expr_app expr_select expr_simple bind inheritsrc formal
%type <ts> binds ids expr_list formals
%token <t> ID INT STR PATH URI
%token IF THEN ELSE ASSERT WITH LET REC INHERIT EQ NEQ AND OR IMPL
%nonassoc IMPL
%left OR
%left AND
%nonassoc EQ NEQ
%right UPDATE
%left NEG
%left '+'
%right CONCAT
%nonassoc '?'
%nonassoc '~'
%%
start: expr { setParseResult(data, $1); };
expr: expr_function;
expr_function
: '{' formals '}' ':' expr_function
{ $$ = makeFunction($2, $5, CUR_POS); }
| ID ':' expr_function
{ $$ = makeFunction1($1, $3, CUR_POS); }
| ASSERT expr ';' expr_function
{ $$ = makeAssert($2, $4, CUR_POS); }
| WITH expr ';' expr_function
{ $$ = makeWith($2, $4, CUR_POS); }
| expr_if
;
expr_if
: IF expr THEN expr ELSE expr
{ $$ = makeIf($2, $4, $6); }
| expr_op
;
expr_op
: '!' expr_op %prec NEG { $$ = makeOpNot($2); }
| expr_op EQ expr_op { $$ = makeOpEq($1, $3); }
| expr_op NEQ expr_op { $$ = makeOpNEq($1, $3); }
| expr_op AND expr_op { $$ = makeOpAnd($1, $3); }
| expr_op OR expr_op { $$ = makeOpOr($1, $3); }
| expr_op IMPL expr_op { $$ = makeOpImpl($1, $3); }
| expr_op UPDATE expr_op { $$ = makeOpUpdate($1, $3); }
| expr_op '~' expr_op { $$ = makeSubPath($1, $3); }
| expr_op '?' ID { $$ = makeOpHasAttr($1, $3); }
| expr_op '+' expr_op { $$ = makeOpPlus($1, $3); }
| expr_op CONCAT expr_op { $$ = makeOpConcat($1, $3); }
| expr_app
;
expr_app
: expr_app expr_select
{ $$ = makeCall($1, $2); }
| expr_select { $$ = $1; }
;
expr_select
: expr_select '.' ID
{ $$ = makeSelect($1, $3); }
| expr_simple { $$ = $1; }
;
expr_simple
: ID { $$ = makeVar($1); }
| INT { $$ = makeInt(ATgetInt((ATermInt) $1)); }
| STR { $$ = makeStr($1); }
| PATH { $$ = makePath(absParsedPath(data, $1)); }
| URI { $$ = makeUri($1); }
| '(' expr ')' { $$ = $2; }
/* Let expressions `let {..., body = ...}' are just desugared
into `(rec {..., body = ...}).body'. */
| LET '{' binds '}'
{ $$ = makeSelect(fixAttrs(1, $3), toATerm("body")); }
| REC '{' binds '}'
{ $$ = fixAttrs(1, $3); }
| '{' binds '}'
{ $$ = fixAttrs(0, $2); }
| '[' expr_list ']' { $$ = makeList($2); }
;
binds
: binds bind { $$ = ATinsert($1, $2); }
| { $$ = ATempty; }
;
bind
: ID '=' expr ';'
{ $$ = makeBind($1, $3, CUR_POS); }
| INHERIT inheritsrc ids ';'
{ $$ = makeInherit($2, $3, CUR_POS); }
;
inheritsrc
: '(' expr ')' { $$ = $2; }
| { $$ = makeScope(); }
;
ids: ids ID { $$ = ATinsert($1, $2); } | { $$ = ATempty; };
expr_list
: expr_select expr_list { $$ = ATinsert($2, $1); }
/* yes, this is right-recursive, but it doesn't matter since
otherwise we would need ATreverse which requires unbounded
stack space */
| { $$ = ATempty; }
;
formals
: formal ',' formals { $$ = ATinsert($3, $1); } /* idem - right recursive */
| formal { $$ = ATinsert(ATempty, $1); }
;
formal
: ID { $$ = makeNoDefFormal($1); }
| ID '?' expr { $$ = makeDefFormal($1, $3); }
;
%%
|
