diff options
Diffstat (limited to 'compiler/parser/Lexer.x')
| -rw-r--r-- | compiler/parser/Lexer.x | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/compiler/parser/Lexer.x b/compiler/parser/Lexer.x index 3a001bd08e..a4a343985a 100644 --- a/compiler/parser/Lexer.x +++ b/compiler/parser/Lexer.x @@ -1981,7 +1981,9 @@ alternativeLayoutRuleToken t mExpectingOCurly <- getAlrExpectingOCurly justClosedExplicitLetBlock <- getJustClosedExplicitLetBlock setJustClosedExplicitLetBlock False - let thisLoc = getLoc t + dflags <- getDynFlags + let transitional = dopt Opt_AlternativeLayoutRuleTransitional dflags + thisLoc = getLoc t thisCol = srcSpanStartCol thisLoc newLine = (lastLoc == noSrcSpan) || (srcSpanStartLine thisLoc > srcSpanEndLine lastLoc) @@ -2040,6 +2042,18 @@ alternativeLayoutRuleToken t do setPendingImplicitTokens [t] setALRContext ls return (L thisLoc ITccurly) + -- This next case is to handle a transitional issue: + (ITwhere, ALRLayout _ col : ls, _) + | newLine && thisCol == col && transitional -> + do addWarning Opt_WarnAlternativeLayoutRuleTransitional + thisLoc + (transitionalAlternativeLayoutWarning + "`where' clause at the same depth as implicit layout block") + setALRContext ls + setNextToken t + -- Note that we use lastLoc, as we may need to close + -- more layouts, or give a semicolon + return (L lastLoc ITccurly) (_, ALRLayout _ col : ls, _) | newLine && thisCol == col -> do setNextToken t @@ -2090,6 +2104,11 @@ alternativeLayoutRuleToken t -- the other ITwhere case omitted; general case below covers it (_, _, _) -> return t +transitionalAlternativeLayoutWarning :: String -> SDoc +transitionalAlternativeLayoutWarning msg + = text "transitional layout will not be accepted in the future:" + $$ text msg + isALRopen :: Token -> Bool isALRopen ITcase = True isALRopen ITif = True |