Language.Rust.Data.InputStream

These are the only functions that need to be implemented in order to use the parser. Whether this wraps ByteString or String depends on whether the useByteStrings option is on or not (it is by default). Using ByteString means better handling of weird characters (takeByte for plain String fails badly if you try to take a byte that doesn't fall on a character boundary), but it means incurring a dependency on the utf8-string package.

InputStream type

data InputStream

Opaque input type.

Instances

Eq InputStream

Methods

(==) :: InputStream -> InputStream -> Bool

(/=) :: InputStream -> InputStream -> Bool

Ord InputStream

Methods

compare :: InputStream -> InputStream -> Ordering

(<) :: InputStream -> InputStream -> Bool

(<=) :: InputStream -> InputStream -> Bool

(>) :: InputStream -> InputStream -> Bool

(>=) :: InputStream -> InputStream -> Bool

max :: InputStream -> InputStream -> InputStream

min :: InputStream -> InputStream -> InputStream

Show InputStream

Methods

showsPrec :: Int -> InputStream -> ShowS

show :: InputStream -> String

showList :: [InputStream] -> ShowS

IsString InputStream

Uses inputStreamFromString

Methods

fromString :: String -> InputStream

countLines :: InputStream -> Int

Returns the number of text lines in the given InputStream

>>> countLines ""
0

>>> countLines "foo"
1

>>> countLines "foo\n\nbar"
3

>>> countLines "foo\n\nbar\n"
3

inputStreamEmpty :: InputStream -> Bool

Return True if the given input stream is empty.

>>> inputStreamEmpty ""
True

>>> inputStreamEmpty "foo"
False

Introduction forms

readInputStream :: FilePath -> IO InputStream

Read an encoded file into an InputStream

hReadInputStream :: Handle -> IO InputStream

Read an InputStream from a Handle

inputStreamFromString :: String -> InputStream

Convert a String to an InputStream.

Elimination forms

inputStreamToString :: InputStream -> String

Convert InputStream to String.

takeByte :: InputStream -> (Word8, InputStream)

Read the first byte from an InputStream and return that byte with what remains of the InputStream. Behaviour is undefined when inputStreamEmpty returns True.

>>> takeByte "foo bar"
(102, "oo bar")

>>> takeByte "Ĥăƨĸëļļ"
(196, "\ETX\168\&8\235<<")

takeChar :: InputStream -> (Char, InputStream)

Read the first character from an InputStream and return that Char with what remains of the InputStream. Behaviour is undefined when inputStreamEmpty returns True.

>>> takeChar "foo bar"
('f', "oo bar")

>>> takeChar "Ĥăƨĸëļļ"
('Ĥ', "ăƨĸëļļ")

peekChars :: Int -> InputStream -> String

Returns the first n characters of the given input stream, without removing them.

>>> peekChars 5 "foo bar"
"foo ba"

>>> peekChars 5 "foo"
"foo"

>>> peekChars 3 "Ĥăƨĸëļļ"
"Ĥăƨ"