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Text.ParserCombinators.UU.BasicInstances

Contents

Data Types
Types
Classes
Functions

Description

This module contains basic instances for the class interface described in the Text.ParserCombinators.UU.Core module. It demonstates how to construct and maintain a state during parsing. In the state we store error messages, positional information and the actual input that is being parsed. Unless you have very specific wishes the module can be used as such. Since we make use of the Data.ListLike interface a wide variety of input structures can be handled.

Synopsis

Data Types

data Error pos Source

The data type Error describes the various kinds of errors which can be generated by the instances in this module

Constructors

Inserted String pos Strings	`String` was inserted at `pos`-ition, where we expected `Strings`
Deleted String pos Strings	`String` was deleted at `pos`-ition, where we expected `Strings`
Replaced String String pos Strings	for future use
DeletedAtEnd String	the unconsumed part of the input was deleted

Instances

Show pos => Show (Error pos)
StoresErrors (Str a s loc) (Error loc)

data Str a s loc Source

The data type Str holds the input data to be parsed, the current location, the error messages generated and whether it is ok to delete elements from the input. Since an insert/delete action is the same as a delete/insert action we try to avoid the first one. So: no deletes after an insert.

Constructors

Str
Fields input :: s the unconsumed part of the input msgs :: [Error loc] the accumulated error messages pos :: loc the current input position deleteOk :: !Bool we want to avoid deletions after insertions

Instances

(Show a, ListLike s a) => Eof (Str a s loc)
HasPosition (Str a s loc) loc
(Idiomatic (Str Char state loc) f g, IsLocationUpdatedBy loc Char, ListLike state Char) => Idiomatic (Str Char state loc) f (Char -> g)
(Idiomatic (Str Char state loc) f g, IsLocationUpdatedBy loc Char, ListLike state Char) => Idiomatic (Str Char state loc) f (String -> g)
StoresErrors (Str a s loc) (Error loc)

data Insertion a Source

the String describes what is being inserted, the a parameter the value which is to be inserted and the cost the prices to be paid.

Constructors

Insertion String a Cost

data LineCol Source

Constructors

LineCol !Int !Int

Instances

Show LineCol
IsLocationUpdatedBy LineCol Char

data LineColPos Source

Constructors

LineColPos !Int !Int !Int

Instances

Show LineColPos
IsLocationUpdatedBy LineColPos Char

Types

type Parser a = (IsLocationUpdatedBy loc Char, ListLike state Char) => P (Str Char state loc) aSource

A Parser is a parser that is prepared to accept Data.Listlike input; hence we can deal with String's, ByteString's, etc.

type ParserTrafo a b = (IsLocationUpdatedBy loc Char, ListLike state Char) => P (Str Char state loc) a -> P (Str Char state loc) bSource

A ParserTrafo a b maps a Parser a onto a Parser b.

Classes

class Show loc => IsLocationUpdatedBy loc str Source

The input state may maintain a location which can be used in generating error messages. Since we do not want to fix our input to be just a String we provide an interface which can be used to advance this location by passing information about the part recognised. This function is typically called in the splitState functions.

Instances

IsLocationUpdatedBy Int Char
IsLocationUpdatedBy Int Word8
IsLocationUpdatedBy LineColPos Char
IsLocationUpdatedBy LineCol Char
IsLocationUpdatedBy loc a => IsLocationUpdatedBy loc [a]

Functions

createStr :: ListLike s a => loc -> s -> Str a s locSource

createStr initialises the input stream with the input data and the initial position. There are no error messages yet.

show_expecting :: Show pos => pos -> [String] -> String Source

pSatisfy :: forall loc state a. (Show a, loc `IsLocationUpdatedBy` a, ListLike state a) => (a -> Bool) -> Insertion a -> P (Str a state loc) aSource

pSatisfy describes and elementary parsing step. Its first parameter check whether the head element of the input can be recognised, and the second parameter how to proceed in case an element recognised by this parser is absent, and parsing may proceed by pretending such an element was present in the input anayway.

pRangeInsert :: (Ord a, Show a, IsLocationUpdatedBy loc a, ListLike state a) => (a, a) -> Insertion a -> P (Str a state loc) aSource

pRangeInsert recognises an element between a lower and an upper bound. Furthermore it can be specified what element is to be inserted in case such an element is not at the head of the input.

pRange :: (Ord a, Show a, IsLocationUpdatedBy loc a, ListLike state a) => (a, a) -> P (Str a state loc) aSource

pRange uses the information from the bounds to compute the Insertion information.

pSymInsert :: (Eq a, Show a, IsLocationUpdatedBy loc a, ListLike state a) => a -> Insertion a -> P (Str a state loc) aSource

pSymInsert recognises a specific element. Furthermore it can be specified what element is to be inserted in case such an element is not at the head of the input.

pSym :: (Eq a, Show a, IsLocationUpdatedBy loc a, ListLike state a) => a -> P (Str a state loc) aSource

pSym recognises a specific element. Furthermore it can be specified what element. Information about Insertion is derived from the parameter. is to be inserted in case such an element is not at the head of the input.

pToken :: forall loc state a. (Show a, Eq a, loc `IsLocationUpdatedBy` a, ListLike state a) => [a] -> P (Str a state loc) [a]Source

pTokenCost :: forall loc state a. (Show a, Eq a, loc `IsLocationUpdatedBy` a, ListLike state a) => [a] -> Int -> P (Str a state loc) [a]Source

pTokenCost succeeds if its parameter is a prefix of the input.

pMunch :: forall loc state a. (Show a, loc `IsLocationUpdatedBy` a, ListLike state a) => (a -> Bool) -> P (Str a state loc) [a]Source

pMunch recognises the longest prefix of the input for which the passed predicate holds. The message parameer is used when tracing has been switched on.