[Haskell-cafe] parsec: parserFail & multiple error messages
silly8888
silly8888 at gmail.com
Wed Aug 8 21:24:31 CEST 2012
I am trying to create a parsec parser that parses an integer and then
checks if that integer has the right size. If not, it generates an
error.
I tried the following:
8<---------------------------------------------------------------
import Text.Parsec
import Text.Parsec.String
integer :: Parser Int
integer = do s <- many1 digit
let n = read s
if n > 65535 then
parserFail "integer overflow"
else
return n
8<---------------------------------------------------------------
The problem is that when I try this
parse integer "" "70000"
I get the following error:
Left (line 1, column 6):
unexpected end of input
expecting digit
integer overflow
ie there are three error messages but I only want the last one. Is
there something I can do about this?
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