libxml2: xmlregexp.h File Reference

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Typedefs | Functions
xmlregexp.h File Reference

Regular expressions. More...

## Typedefs
typedef struct _xmlRegexp | xmlRegexp
| A libxml regular expression.
typedef struct _xmlRegExecCtxt | xmlRegExecCtxt
| A libxml progressive regular expression evaluation context.
typedef void(*) | xmlRegExecCallbacks(xmlRegExecCtxt *exec, const xmlChar *token, void *transdata, void *inputdata)
| Callback function when doing a transition in the automata.

## Functions
xmlRegexp * | xmlRegexpCompile (const xmlChar *regexp)
| Parses an XML Schemas regular expression.
void | xmlRegFreeRegexp (xmlRegexp *regexp)
| Free a regexp.
int | xmlRegexpExec (xmlRegexp *comp, const xmlChar *value)
| Check if the regular expression matches a string.
void | xmlRegexpPrint (FILE *output, xmlRegexp *regexp)
| No-op since 2.14.0.
int | xmlRegexpIsDeterminist (xmlRegexp *comp)
| Check if the regular expression is deterministic.
xmlRegExecCtxt * | xmlRegNewExecCtxt (xmlRegexp *comp, xmlRegExecCallbacks callback, void *data)
| Build a context used for progressive evaluation of a regexp.
void | xmlRegFreeExecCtxt (xmlRegExecCtxt *exec)
| Free the structures associated to a regular expression evaluation context.
int | xmlRegExecPushString (xmlRegExecCtxt *exec, const xmlChar *value, void *data)
| Push one input token in the execution context.
int | xmlRegExecPushString2 (xmlRegExecCtxt *exec, const xmlChar *value, const xmlChar *value2, void *data)
| Push one input token in the execution context.
int | xmlRegExecNextValues (xmlRegExecCtxt *exec, int *nbval, int *nbneg, xmlChar **values, int *terminal)
| Extract information from the regexp execution.
int | xmlRegExecErrInfo (xmlRegExecCtxt *exec, const xmlChar **string, int *nbval, int *nbneg, xmlChar **values, int *terminal)
| Extract error information from the regexp execution.

## Detailed Description

Regular expressions.

A regular expression engine used for DTD and XML Schema validation.

Copyright
  See Copyright for the status of this software.

Author
  Daniel Veillard

## Typedef Documentation

## ◆ xmlRegExecCallbacks

typedef void(*) xmlRegExecCallbacks(xmlRegExecCtxt *exec, const xmlChar *token, void *transdata, void *inputdata)

Callback function when doing a transition in the automata.

Parameters

  exec | the regular expression context
  token | the current token string
  transdata | transition data
  inputdata | input data

## Function Documentation

## ◆ xmlRegExecErrInfo()

int xmlRegExecErrInfo | ( | xmlRegExecCtxt * | exec,
|  | const xmlChar ** | string,
|  | int * | nbval,
|  | int * | nbneg,
|  | xmlChar ** | values,
|  | int * | terminal )

Extract error information from the regexp execution.

The parameter string will be updated with the value pushed and not accepted, the parameter values must point to an array of nbval string pointers on return nbval will contain the number of possible strings in that state and the values array will be updated with them. The string values returned will be freed with the exec context and don't need to be deallocated.

Deprecated
  Internal function, don't use.

Parameters

  exec | a regexp execution context generating an error
  string | return value for the error string
  nbval | pointer to the number of accepted values IN/OUT
  nbneg | return number of negative transitions
  values | pointer to the array of acceptable values
  terminal | return value if this was a terminal state

Returns
  0 in case of success or -1 in case of error.

## ◆ xmlRegExecNextValues()

int xmlRegExecNextValues | ( | xmlRegExecCtxt * | exec,
|  | int * | nbval,
|  | int * | nbneg,
|  | xmlChar ** | values,
|  | int * | terminal )

Extract information from the regexp execution.

The parameter values must point to an array of nbval string pointers on return nbval will contain the number of possible strings in that state and the values array will be updated with them. The string values returned will be freed with the exec context and don't need to be deallocated.

Deprecated
  Internal function, don't use.

Parameters

  exec | a regexp execution context
  nbval | pointer to the number of accepted values IN/OUT
  nbneg | return number of negative transitions
  values | pointer to the array of acceptable values
  terminal | return value if this was a terminal state

Returns
  0 in case of success or -1 in case of error.

## ◆ xmlRegExecPushString()

int xmlRegExecPushString | ( | xmlRegExecCtxt * | exec,
|  | const xmlChar * | value,
|  | void * | data )

Push one input token in the execution context.

Deprecated
  Internal function, don't use.

Parameters

  exec | a regexp execution context or NULL to indicate the end
  value | a string token input
  data | data associated to the token to reuse in callbacks

Returns
  1 if the regexp reached a final state, 0 if non-final, and a negative value in case of error.

## ◆ xmlRegExecPushString2()

int xmlRegExecPushString2 | ( | xmlRegExecCtxt * | exec,
|  | const xmlChar * | value,
|  | const xmlChar * | value2,
|  | void * | data )

Push one input token in the execution context.

Deprecated
  Internal function, don't use.

Parameters

  exec | a regexp execution context or NULL to indicate the end
  value | the first string token input
  value2 | the second string token input
  data | data associated to the token to reuse in callbacks

Returns
  1 if the regexp reached a final state, 0 if non-final, and a negative value in case of error.

## ◆ xmlRegexpCompile()

xmlRegexp * xmlRegexpCompile | ( | const xmlChar * | regexp | ) |

Parses an XML Schemas regular expression.

Parses a regular expression conforming to XML Schemas Part 2 Datatype Appendix F and builds an automata suitable for testing strings against that regular expression.

Parameters

  regexp | a regular expression string

Returns
  the compiled expression or NULL in case of error

## ◆ xmlRegexpExec()

int xmlRegexpExec | ( | xmlRegexp * | comp,
|  | const xmlChar * | content )

Check if the regular expression matches a string.

Parameters

  comp | the compiled regular expression
  content | the value to check against the regular expression

Returns
  1 if it matches, 0 if not and a negative value in case of error

## ◆ xmlRegexpIsDeterminist()

int xmlRegexpIsDeterminist | ( | xmlRegexp * | comp | ) |

Check if the regular expression is deterministic.

DTD and XML Schemas require a deterministic content model, so the automaton compiled from the regex must be a DFA.

The runtime of this function is quadratic in the number of outgoing edges, causing serious worst-case performance issues.

Deprecated
  : Internal function, don't use.

Parameters

  comp | the compiled regular expression

Returns
  1 if it yes, 0 if not and a negative value in case of error

## ◆ xmlRegexpPrint()

void xmlRegexpPrint | ( | FILE * | output,
|  | xmlRegexp * | regexp )

No-op since 2.14.0.

Deprecated
  Don't use.

Parameters

  output | the file for the output debug
  regexp | the compiled regexp

## ◆ xmlRegFreeExecCtxt()

void xmlRegFreeExecCtxt | ( | xmlRegExecCtxt * | exec | ) |

Free the structures associated to a regular expression evaluation context.

Deprecated
  Internal function, don't use.

Parameters

  exec | a regular expression evaluation context

## ◆ xmlRegFreeRegexp()

void xmlRegFreeRegexp | ( | xmlRegexp * | regexp | ) |

Free a regexp.

Parameters

  regexp | the regexp

## ◆ xmlRegNewExecCtxt()

xmlRegExecCtxt * xmlRegNewExecCtxt | ( | xmlRegexp * | comp,
|  | xmlRegExecCallbacks | callback,
|  | void * | data )

Build a context used for progressive evaluation of a regexp.

Deprecated
  Internal function, don't use.

Parameters

  comp | a precompiled regular expression
  callback | a callback function used for handling progresses in the automata matching phase
  data | the context data associated to the callback in this context

Returns
  the new context