diff options
| -rw-r--r-- | src/compiler/scala/tools/nsc/ast/parser/Parsers.scala | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala b/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala index 68651fc1c9..28cb088f4e 100644 --- a/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala +++ b/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala @@ -1631,15 +1631,24 @@ self => * }}} */ def generator(enums: ListBuffer[Enumerator], eqOK: Boolean) { - val start = in.offset - if (in.token == VAL) in.nextToken() - val pat = noSeq.pattern1() + val start = in.offset + val hasVal = in.token == VAL + if (hasVal) + in.nextToken() + + val pat = noSeq.pattern1() val point = in.offset - val tok = in.token - if (tok == EQUALS && eqOK) in.nextToken() + val hasEq = in.token == EQUALS + + if (hasVal && !hasEq) + syntaxError(in.offset, "val in for comprehension must be followed by assignment") + if (!hasVal && hasEq) + syntaxError(in.offset, "assignment in for comprehension must be preceded by `val`") + + if (hasEq && eqOK) in.nextToken() else accept(LARROW) val rhs = expr() - enums += makeGenerator(r2p(start, point, in.lastOffset max start), pat, tok == EQUALS, rhs) + enums += makeGenerator(r2p(start, point, in.lastOffset max start), pat, hasEq, rhs) // why max above? IDE stress tests have shown that lastOffset could be less than start, // I guess this happens if instead if a for-expression we sit on a closing paren. while (in.token == IF) enums += makeFilter(in.offset, guard()) |