FixedLengthUtil::FixedLengthDataIterator Class Reference

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

Inheritance diagram for FixedLengthUtil::FixedLengthDataIterator:

Public Member Methods
	constructor (string data, hash spec, *hash opts)
	Instantiates the FixedLengthDataIterator object. More...
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 spec, *hash opts)
	Instantiates the FixedLengthAbstractIterator object. More...
*hash	getValue ()
	Returns the current record as a hash. More...
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 type)
	parses the input value based on global configuration and the current field definition

Additional Inherited Members
Private Member Methods inherited from FixedLengthUtil::FixedLengthAbstractIterator
*hash	checkOptions (*hash opts)
	Validate and prepare global fixed-length options. More...
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

Detailed Description

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

Example:

string data = "00001AV\n00002BN\00003CZ\n";

hash 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", # use global if omitted
        ),
    ),
);

hash global_options = (
    "encoding"    : "UTF-8",
    "eol"         : "\n",
    "ignore_empty": True,
    "timezone"    : "Europe/Prague", # used if not overridden in a date field specification
);

FixedLengthDataIterator i(data, specs, global_options);
while (i.next()) {
    operation_with_hash(i.getValue())
}

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::FixedLengthDataIterator::constructor	(	string	data,
		hash	spec,
		*hash	opts
	)

Instantiates the FixedLengthDataIterator object.

Example:

hash 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", # use global if omitted
        ),
    ),
);

hash global_options = (
    "encoding"    : "UTF-8",
    "eol"         : "\n",
    "ignore_empty": True,
    "timezone"    : "Europe/Prague", # used if not overridden in a date field specification
);

FixedLengthDataIterator i(string, specs, global_options);
while (i.next()) {
    operation_with_hash(i.getValue())
}

Parameters

data	The input string to process
spec	Fixed-length line specification; see Specification Hash for more information
opts	Global options; see Global Options for valid values