Sometimes I face to weird issue, consider following examples:
This compiles:
renderFrame :: Frame -> Fay ()
renderFrame frame = do
stack <- getStack
if length stack > 0
then (do
let e = head stack
traceEventCoord e)
else (do return ())
reqFrame renderFrame
emptyStack
where traceEventCoord :: Event -> Fay ()
traceEventCoord e = do
eX <- pageX e
eY <- pageY e
let str = show eX ++ " x " ++ show eY
trace <- elById "trace"
if isNull trace
then return ()
else elSetHtml (fromNullable trace) str
pageX :: Event -> Fay Int
pageX = ffi "%1['pageX']"
pageY :: Event -> Fay Int
pageY = ffi "%1['pageY']"
So does it:
getParentGroups :: Fragment -> Fay [Fragment]
getParentGroups f = do
p <- getParent f
nn <- nodeName (fromNullable p)
return [fromNullable p]
getParent :: Fragment -> Fay (Nullable Fragment)
getParent = ffi "%1.parent()"
nodeName :: Fragment -> Fay String
nodeName = ffi "%1.node.nodeName"
But if I put auxiliary functions within where block I have compilation error:
fay: your FFI declaration needs a type signature pageX = ffi "%1['pageX']"fay: your FFI declaration needs a type signature: getParent = ffi "%1.parent()"
E.g.
-- ...
where traceEventCoord :: Event -> Fay ()
traceEventCoord e = do
eX <- pageX e
eY <- pageY e
let str = show eX ++ " x " ++ show eY
trace <- elById "trace"
if isNull trace
then return ()
else elSetHtml (fromNullable trace) str
pageX :: Event -> Fay Int
pageX = ffi "%1['pageX']"
pageY :: Event -> Fay Int
pageY = ffi "%1['pageY']"
and
getParentGroups f = do
p <- getParent f
nn <- nodeName (fromNullable p)
return [fromNullable p]
where
getParent :: Fragment -> Fay (Nullable Fragment)
getParent = ffi "%1.parent()"
nodeName :: Fragment -> Fay String
nodeName = ffi "%1.node.nodeName"
Notice, that traceEventCoords in first example do not invokes this issue.
Is it a bug?
P.S. Second example is a just an example and final code would be refactored a bit, but it holds for demonstrative purpose.
