ASCII parsers

The basic template for all parsers is pni::parser

template<typename T>
class pni::parser

parser for primitive types

This version of the parser structure provides a default parsing implementation for primitive types. The aim of this class is to hide all the complexity of the boost::spirit::qi parsers. In addition it catches all spirit exceptions and wraps them into a parser_error exception.

Use this parser to parse a single primitive value from a string. The input data must be trimmed - so no leading or trailing blanks are allowed. The string is supposed to end with the last character assembling the value to parse.

By default the output iterator is a const string iterator.

Template Parameters

  • T: primitive data type

Public Functions

result_type operator()(const pni::string &data) const

parser primitive type

Parses the input string and returns an instance of a primitive type. In case of errors parser_error is thrown.

Return

instance of the primitive type

Exceptions
Parameters

  • data: the string with input data

Parser specializations

template<>
class parser<pni::value>

parser for general values

This is a specialization of the parser class for the value type erasure. The parser tries to identify the value provided by the data string and converts it to the appropriate type which will then be wrapped in an instance of pni::value.

The class currently supports the following types

  • 64Bit integer

  • 64Bit floating point

  • 64Bit complex floats

  • and strings

template<>
class pni::parser<pni::bool_t>

parser specialization for bool values

This specialization of the parser template reads boolean values from a string. The parser uses regular expressions to distinguish between strings representing true and false.

When instantiated using the default constructor

  • TRUE, true and True are interpreted as true

  • and FALSE, false and False as false.

Public Functions

parser()

default constructor

With the default constructor the following regular expressions are used to distinguish between true and false

  • for true - ^T(rue|RUE)|true|1$

  • for false - ^F(alse|ALSE)|false|0$

parser(const pni::string &true_regex, const pni::string &false_regex)

constructor

With this constructor the regular expressions used for true and false values can be customized.

Parameters

  • true_regex: regular expression evaluating to true

  • false_regex: regular expression evaluating to false

template<>
class parser<pni::slice>
template<>
class parser<pni::string>

parsing strings

This specialization of the parser template parses strings form user input. Virtually this class does nothing it just passes the string provided by the user right through.

template<typename T>
class pni::parser<std::vector<T>>

std::vector parser

This parser reads a linear container of data from a string. The data type of the container is assumed to be homogeneous. This means that all elements must match with the parser selected for the element type.

In their string representation container data is assumed to be embraced between a start and a stop token. The elements are assumed to be separated by a delimiter token.

The container can be any STL compliant container type.

Template Parameters

  • T: the value type of the vector

Public Functions

parser(const container_io_config &config = container_io_config())

constructor

With this constructor a container IO configuration can be passed which determines the value seperator, start and stop symbols.

Parameters

  • config: reference to the IO configuration

template<typename T>
class parser<std::complex<T>>

parser specialization for complex numbers

This parser reads complex numbers from a string.

Template Parameters

  • T: base type for the complex number