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| Contents |
- Entry points to the lexer
- Token and position types
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| Description |
You don't normally need to use this Lex module directly - it is
called automatically by the parser. (This interface is only exposed
for debugging purposes.) This is a hand-written lexer for tokenising the text of an XML
document so that it is ready for parsing. It attaches position
information in (line,column) format to every token. The main
entry point is . A secondary entry point, , is
provided for when the parser needs to stuff a string back onto
the front of the text and re-tokenise it (typically when expanding
macros). As one would expect, the lexer is essentially a small finite
state machine. |
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| Synopsis |
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| Entry points to the lexer |
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| :: String -> String -> [Token] |
| The first argument to is the filename (used for source positions,
especially in error messages), and the second is the string content of
the XML file. |
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| :: Posn -> String -> [Token] |
| is used when the parser expands a macro (PE reference).
The expansion of the macro must be re-lexed as if for the first time. |
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| posInNewCxt :: String -> Maybe Posn -> Posn |
| posInNewCxt name pos creates a new source position from an old one.
It is used when opening a new file (e.g. a DTD inclusion), to denote
the start of the file name, but retain the stacked information that
it was included from the old pos. |
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| Token and position types |
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| type Token = (Posn, TokenT) |
| All tokens are paired up with a source position. |
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| data Posn |
| Source positions contain a filename, line, column, and an
inclusion point, which is itself another source position,
recursively. | | Constructors | | Pn String Int Int (Maybe Posn) | |
| | Instances | |
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| data TokenT |
| The basic token type. | | Constructors | | TokCommentOpen | <!-- | | TokCommentClose | --> | | TokPIOpen | <? | | TokPIClose | ?> | | TokSectionOpen | <![ | | TokSectionClose | ]]> | | TokSection Section | CDATA INCLUDE IGNORE etc | | TokSpecialOpen | <! | | TokSpecial Special | DOCTYPE ELEMENT ATTLIST etc | | TokEndOpen | </ | | TokEndClose | /> | | TokAnyOpen | < | | TokAnyClose | > | | TokSqOpen | [ | | TokSqClose | ] | | TokEqual | = | | TokQuery | ? | | TokStar | * | | TokPlus | + | | TokAmp | & | | TokSemi | ; | | TokHash | # | | TokBraOpen | ( | | TokBraClose | ) | | TokPipe | | | | TokPercent | % | | TokComma | , | | TokQuote | '' or "" | | TokName String | begins with letter | | TokFreeText String | any character data | | TokNull | fake token |
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| data Special |
| Constructors | | DOCTYPEx | | | ELEMENTx | | | ATTLISTx | | | ENTITYx | | | NOTATIONx | |
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| data Section |
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| Produced by Haddock version 0.4 |
