diff options
Diffstat (limited to 'src/libexpr')
| -rw-r--r-- | src/libexpr/eval.cc | 9 | ||||
| -rw-r--r-- | src/libexpr/parser.y | 2 |
2 files changed, 10 insertions, 1 deletions
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 2281ee7212c9..0623e4953239 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -288,10 +288,17 @@ Expr evalExpr2(EvalState & state, Expr e) if (atMatch(m, e) >> "OpOr" >> e1 >> e2) return makeBool(evalBool(state, e1) || evalBool(state, e2)); - /* Attribut set update (//). */ + /* Attribute set update (//). */ if (atMatch(m, e) >> "OpUpdate" >> e1 >> e2) return updateAttrs(evalExpr(state, e1), evalExpr(state, e2)); + /* Attribute existence test (?). */ + if (atMatch(m, e) >> "OpHasAttr" >> e1 >> name) { + ATermMap attrs; + queryAllAttrs(evalExpr(state, e1), attrs); + return makeBool(attrs.get(name) != 0); + } + /* Barf. */ throw badTerm("invalid expression", e); } diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y index b1fe9e093145..cfcbc589f61c 100644 --- a/src/libexpr/parser.y +++ b/src/libexpr/parser.y @@ -44,6 +44,7 @@ void yyerror(YYLTYPE * loc, yyscan_t scanner, void * data, char * s) %nonassoc EQ NEQ %right UPDATE %left NEG +%nonassoc '?' %nonassoc '~' %% @@ -81,6 +82,7 @@ expr_op | expr_op IMPL expr_op { $$ = ATmake("OpImpl(<term>, <term>)", $1, $3); } | expr_op UPDATE expr_op { $$ = ATmake("OpUpdate(<term>, <term>)", $1, $3); } | expr_op '~' expr_op { $$ = ATmake("SubPath(<term>, <term>)", $1, $3); } + | expr_op '?' ID { $$ = ATmake("OpHasAttr(<term>, <term>)", $1, $3); } | expr_app ; |