Qore FixedLengthUtil Module Reference 1.5
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FixedLengthUtil::FixedLengthFileIterator Class Reference

Structured line iterator for fixed-length line files allowing efficient "pipelined" processing. More...

#include <FixedLengthFileIterator.qc.dox.h>

Inheritance diagram for FixedLengthUtil::FixedLengthFileIterator:
[legend]

Public Member Methods

 constructor (string path, hash< auto > spec, *hash< auto > opts)
 Instantiates the FixedLengthFileIterator object. More...
 
string getEncoding ()
 Returns the character encoding for the file.
 
string getFileName ()
 Returns the file path/name used to open the file.
 
hash< Qore::StatInfohstat ()
 Returns a StatInfo hash of the underlying file.
 
list< auto > stat ()
 Returns a stat list of the underlying file.
 
- Public Member Methods inherited from FixedLengthUtil::FixedLengthAbstractIterator
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. More...
 
 constructor (AbstractLineIterator li, hash< auto > spec, *hash< auto > opts)
 Instantiates the FixedLengthAbstractIterator object. More...
 
*hash< auto > getValue ()
 Returns the current record as a hash. More...
 
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. More...
 
*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. More...
 
bool next ()
 Moves the current line / record position to the next line / record; returns False if there are no more lines to iterate. More...
 
auto transform (auto value, hash< auto > type)
 parses the input value based on global configuration and the current field definition
 
- Public Member Methods 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.
 

Private Attributes

string m_file_path
 the path of the file being iterated
 
- Private Attributes inherited from FixedLengthUtil::FixedLengthAbstractIterator
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
 
- Private 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.
 

Additional Inherited Members

- Static Private Member Methods inherited from FixedLengthUtil::FixedLengthAbstractIterator
static *hash< auto > checkOptions (*hash< auto > opts)
 Validate and prepare global fixed-length options. More...
 

Detailed Description

Structured line iterator for fixed-length line files allowing efficient "pipelined" processing.

Example:
#!/usr/bin/env qore
%new-style
%enable-all-warnings
%require-types
%strict-args
%requires FixedLengthUtil
hash<auto> specs = {
"type1": {
"col1": {"length": 5, "type": "int"},
"col2": {"length": 2, "type": "string"},
},
"type2": {
"col3": {"length": 1, "type": "string"},
"col4": {"length": 3, "type": "string"},
"col5": {"length": 8, "type": "date", "format": "DDMMYYYY", "timezone": "Europe/Prague"},
},
};
hash<auto> global_options = {
"encoding" : "UTF-8",
"eol" : "\n",
"ignore_empty": True,
"timezone" : "Europe/Prague", # used if not overridden in a date field specification
};
FixedLengthFileIterator i(file, specs, global_options);
# output all records
map printf("%y\n", $1), i;
See also
  • FixedLengthIterator for a stream-based class providing the same functionality as this class in a more generic way

Member Function Documentation

◆ constructor()

FixedLengthUtil::FixedLengthFileIterator::constructor ( string  path,
hash< auto >  spec,
*hash< auto >  opts 
)

Instantiates the FixedLengthFileIterator object.

Parameters
pathFile path to read
specFixed-length line specification; see Specification Hash for more information
optsGlobal options; see Global Options for more information