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|
%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 backToString(yyscan_t scanner);
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)
/* Make sure that the parse stack is scanned by the ATerm garbage
collector. */
static void * mallocAndProtect(size_t size)
{
void * p = malloc(size);
if (p) ATprotectMemory(p, size);
return p;
}
static void freeAndUnprotect(void * p)
{
ATunprotectMemory(p);
free(p);
}
#define YYMALLOC mallocAndProtect
#define YYFREE freeAndUnprotect
%}
%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 string_parts
%token <t> ID INT STR PATH URI
%token IF THEN ELSE ASSERT WITH LET REC INHERIT EQ NEQ AND OR IMPL
%token DOLLAR_CURLY /* == ${ */
%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)); }
| '"' string_parts '"' {
/* For efficiency, and to simplify parse trees a bit. */
if ($2 == ATempty) $$ = makeStr(toATerm(""));
else if (ATgetNext($2) == ATempty) $$ = ATgetFirst($2);
else $$ = makeConcatStrings(ATreverse($2));
}
| PATH { $$ = 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); }
;
string_parts
: string_parts STR { $$ = ATinsert($1, $2); }
| string_parts DOLLAR_CURLY expr '}' { backToString(scanner); $$ = ATinsert($1, $3); }
| { $$ = ATempty; }
;
binds
: binds bind { $$ = 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); }
;
%%
|
