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FixedLengthUtil::FixedLengthAbstractIterator Class Reference

Structured line iterator for abstract data allowing efficient "pipelined" processing. More...

`#include <FixedLengthAbstractIterator.qc.dox.h>`

Inheritance diagram for FixedLengthUtil::FixedLengthAbstractIterator:
[legend]

## Public Member Functions

bool | checkTransition (*string from, *string to)
| A verification function to be called for each line. This method can be overridden to achieve a begin-to-end validation of the whole input file.
| constructor (AbstractLineIterator li, hash< auto > spec, *hash< auto > opts)
| Instantiates the FixedLengthAbstractIterator object.
*hash< auto > | getValue ()
| Returns the current record as a hash.
bool | identifyRecord (list< auto > rec_rule, string input_line)
| Attempts to identify a single record.
string | identifyType (string input_line)
| Identify a fixed-length line type using identifyTypeImpl(), that may be overridden if necessary.
*string | identifyTypeImpl (string input_line)

Identify a fixed-length line type, given the raw line string. This method performs a lookup to a precalculated table based on line lengths (see constructor()). In case different criteria are needed, eg. when two line types in a spec have the same length and no unique resolving rule are specified, this method needs to be overridden, and will throw an exception, because the precalculated mapping will be empty.

bool | next ()
| Moves the current line / record position to the next line / record; returns False if there are no more lines to iterate.
auto | transform (auto value, hash< auto > type)
| parses the input value based on global configuration and the current field definition
Public Member Functions inherited from FixedLengthUtil::FixedLengthBase
| constructor (hash< auto > m_specs, *hash< auto > m_opts)
| Creates the object from the record specifications.
*hash< string, AbstractDataField > | getRecordType ()
| Returns the description of the record type, if any.

## Static Protected Member Functions

static *hash< auto > | checkOptions (*hash< auto > opts)
| Validate and prepare global fixed-length options.

## Protected Attributes

hash | m_resolve_by_length
| hash of type without rule, i.e.potentially conflicting records; key = record length, value = list of no-rule type names
Protected Attributes inherited from FixedLengthUtil::FixedLengthBase
const | GlobalOptionMap
| Translates from global options to data provider options.
*hash< auto > | m_opts
| Global input or output options.
hash< auto > | m_specs
| The record specifications.

## Detailed Description

Structured line iterator for abstract data allowing efficient "pipelined" processing.

## Member Function Documentation

## checkOptions()

static *hash< auto > FixedLengthUtil::FixedLengthAbstractIterator::checkOptions | ( | *hash< auto > | opts | ) |

staticprotected

Validate and prepare global fixed-length options.

Parameters

  opts | Options passed during class instantiation.

## checkTransition()

bool FixedLengthUtil::FixedLengthAbstractIterator::checkTransition | ( | *string | from,
|  | *string | to
| ) |  |

A verification function to be called for each line. This method can be overridden to achieve a begin-to-end validation of the whole input file.

Parameters

  from | Type of previous line being processed
  to | Type of the current line being processed

## constructor()

FixedLengthUtil::FixedLengthAbstractIterator::constructor | ( | AbstractLineIterator | li,
|  | hash< auto > | spec,
|  | *hash< auto > | opts
| ) |  |

Instantiates the FixedLengthAbstractIterator object.

Parameters

  li | source line iterator
  spec | Fixed-length line specification; see Specification Hash for more information
  opts | Global options; see Global Options for more information

Exceptions

  FIXED-LENGTH-UTIL-INVALID-SPEC | invalid record specification; invalid type or missing field length

## getValue()

*hash< auto > FixedLengthUtil::FixedLengthAbstractIterator::getValue | ( |  | ) |

virtual

Returns the current record as a hash.

Example:
  my hash $h = $i.getValue();

Returns
  The current record as a hash with the following keys:
  - `"type"`: a string giving the record type name
  - `"record"`: a hash giving the parsed record data

Implements Qore::AbstractIterator.

## identifyType()

string FixedLengthUtil::FixedLengthAbstractIterator::identifyType | ( | string | input_line | ) |

Identify a fixed-length line type using identifyTypeImpl(), that may be overridden if necessary.

Parameters

  input_line | Input line to be identified

Returns
  the name of the record corresponding to the input line

Exceptions

  FIXED-LENGTH-UTIL-NON-MATCHING-TYPE | input line cannot be matched to a known record

## identifyTypeImpl()

*string FixedLengthUtil::FixedLengthAbstractIterator::identifyTypeImpl | ( | string | input_line | ) |

Identify a fixed-length line type, given the raw line string. This method performs a lookup to a precalculated table based on line lengths (see constructor()). In case different criteria are needed, eg. when two line types in a spec have the same length and no unique resolving rule are specified, this method needs to be overridden, and will throw an exception, because the precalculated mapping will be empty.

Parameters

  input_line | Input line to be identified

Returns
  the record name or NOTHING if the input cannot be matched

Exceptions

  FIXED-LENGTH-UTIL-NON-MATCHING-TYPE | input line cannot be matched to a known record or the input line's length does not match the expected length

## next()

bool FixedLengthUtil::FixedLengthAbstractIterator::next | ( |  | ) |

virtual

Moves the current line / record position to the next line / record; returns False if there are no more lines to iterate.

This method will return True again after it returns False once if the file being iterated has data that can be iterated, otherwise it will always return False. The iterator object should not be used to retrieve a value after this method returns False.

Returns
  False if there are no lines / records to iterate (in which case the iterator object is invalid and should not be used); True if successful (meaning that the iterator object is valid)

Note
  that empty lines are ignored if "ignore_empty" option is in effect

Implements Qore::AbstractIterator.