restinio::easy_parser Namespace Reference

Namespaces
namespace	impl

Classes
class	parse_error_t
	Information about parsing error. More...
struct	nothing_t
	A special type to be used in the case where there is no need to store produced value. More...
struct	result_value_wrapper
	A template with specializations for different kind of result values and for type nothing. More...
struct	result_wrapper_for
	A metafunction for detection of actual result_value_wrapper type for T. More...
struct	result_value_wrapper< std::vector< T, Args... > >
struct	result_value_wrapper< std::array< T, S > >
struct	result_wrapper_for< impl::std_array_wrapper< T, S > >
	A specialization of result_wrapper_for metafunction for the case of std::array wrapper. More...
struct	result_value_wrapper< std::basic_string< Char, Args... > >
struct	result_value_wrapper< std::map< K, V, Args... > >
struct	result_value_wrapper< nothing_t >
class	digits_to_consume_t
	Limits for number of digits to be extracted during parsing of decimal numbers. More...

Typedefs
template<typename T>
using	result_wrapper_for_t = typename result_wrapper_for<T>::type

Enumerations
enum class	error_reason_t {   unexpected_character , unexpected_eof , no_appropriate_alternative , pattern_not_found ,   unconsumed_input , illegal_value_found , force_only_this_alternative_failed }
	Reason of parsing error. More...

Functions
constexpr digits_to_consume_t	expected_digits (digits_to_consume_t::underlying_int_t total) noexcept
	Create a limit for number of digits to be extracted.
constexpr digits_to_consume_t	expected_digits (digits_to_consume_t::underlying_int_t min, digits_to_consume_t::underlying_int_t max) noexcept
	Create a limit for number of digits to be extracted.
template<typename Target_Type, typename... Clauses>
auto	produce (Clauses &&... clauses)
	A factory function to create a producer that creates an instance of the target type by using specified clauses.
template<typename... Clauses>
auto	alternatives (Clauses &&... clauses)
	A factory function to create an alternatives clause.
template<typename... Clauses>
auto	maybe (Clauses &&... clauses)
	A factory function to create an optional clause.
template<typename... Clauses>
auto	not_clause (Clauses &&... clauses)
	A factory function to create a not_clause.
template<typename... Clauses>
auto	and_clause (Clauses &&... clauses)
	A factory function to create an and_clause.
template<typename... Clauses>
auto	sequence (Clauses &&... clauses)
	A factory function to create a sequence of subclauses.
template<typename... Clauses>
auto	force_only_this_alternative (Clauses &&... clauses)
	An alternative that should be parsed correctly or the parsing of the whole alternatives clause should fail.
template<typename... Clauses>
auto	repeat (std::size_t min_occurences, std::size_t max_occurences, Clauses &&... clauses)
	A factory function to create repetitor of subclauses.
auto	skip () noexcept
	A factory function to create a skip_consumer.
auto	any_symbol_p () noexcept
	A factory function to create an any_symbol_producer.
auto	symbol_p (char expected) noexcept
	A factory function to create a symbol_producer.
auto	any_symbol_if_not_p (char sentinel) noexcept
	A factory function to create a any_symbol_if_not_producer.
auto	caseless_symbol_p (char expected) noexcept
	A factory function to create a caseless_symbol_producer.
auto	symbol_from_range_p (char left, char right) noexcept
	A factory function to create a symbol_from_range_producer.
auto	symbol (char expected) noexcept
	A factory function to create a clause that expects the speficied symbol, extracts it and then skips it.
auto	caseless_symbol (char expected) noexcept
	A factory function to create a clause that expects the speficied symbol, extracts it and then skips it.
auto	symbol_from_range (char left, char right) noexcept
	A factory function to create a clause that expects a symbol from specified range, extracts it and then skips it.
auto	space_p () noexcept
	A factory function to create a space_producer.
auto	space () noexcept
	A factory function to create a clause that expects a space, extracts it and then skips it.
auto	digit_p () noexcept
	A factory function to create a digit_producer.
auto	digit () noexcept
	A factory function to create a clause that expects a decimal digit, extracts it and then skips it.
auto	hexdigit_p () noexcept
	A factory function to create a hexdigit_producer.
auto	hexdigit () noexcept
	A factory function to create a clause that expects a hexadecimal digit, extracts it and then skips it.
template<typename T>
auto	non_negative_decimal_number_p () noexcept
	A factory function to create a non_negative_decimal_number_producer.
template<typename T>
auto	non_negative_decimal_number_p (digits_to_consume_t digits_limit) noexcept
	A factory function to create a non_negative_decimal_number_producer.
template<typename T>
auto	hexadecimal_number_p () noexcept
	A factory function to create a hexadecimal_number_producer.
template<typename T>
auto	hexadecimal_number_p (digits_to_consume_t digits_limit) noexcept
	A factory function to create a hexadecimal_number_producer.
template<typename T>
auto	decimal_number_p () noexcept
	A factory function to create a decimal_number_producer.
template<typename T>
auto	decimal_number_p (digits_to_consume_t digits_limit) noexcept
	A factory function to create a decimal_number_producer.
auto	as_result () noexcept
	A factory function to create a as_result_consumer.
template<typename F>
auto	custom_consumer (F consumer)
	A factory function to create a custom_consumer.
auto	to_container ()
	A factory function to create a to_container_consumer.
auto	to_lower () noexcept
	A factory function to create a to_lower_transformer.
template<typename T>
auto	just (T value) noexcept(noexcept(impl::just_value_transformer_t< T >{value}))
	A special transformer that replaces the produced value by a value specified by a user.
template<typename T>
auto	just_result (T value) noexcept(noexcept(impl::just_result_consumer_t< T >{value}))
	A special consumer that replaces the produced value by a value specified by a user and sets that user-specified value as the result.
template<typename Converter>
auto	convert (Converter &&converter)
	A factory function to create convert_transformer.
auto	exact_p (string_view_t fragment)
	A factory function that creates an instance of exact_fragment_producer.
template<std::size_t Size>
auto	exact_p (const char(&fragment)[Size])
	A factory function that creates an instance of exact_fragment_producer.
auto	exact (string_view_t fragment)
	A factory function that creates an instance of exact_fragment clause.
template<std::size_t Size>
auto	exact (const char(&fragment)[Size])
	A factory function that creates an instance of exact_fragment clause.
auto	caseless_exact_p (string_view_t fragment)
	A factory function that creates an instance of caseless_exact_fragment_producer.
template<std::size_t Size>
auto	caseless_exact_p (const char(&fragment)[Size])
	A factory function that creates an instance of caseless_exact_fragment_producer.
auto	caseless_exact (string_view_t fragment)
	A factory function that creates an instance of caseless_exact_fragment clause.
template<std::size_t Size>
auto	caseless_exact (const char(&fragment)[Size])
	A factory function that creates an instance of caseless_exact_fragment clause.
template<typename Producer>
expected_t< typename Producer::result_type, parse_error_t >	try_parse (string_view_t from, Producer producer)
	Perform the parsing of the specified content by using specified value producer.
std::string	make_error_description (const parse_error_t &error, string_view_t from)
	Make textual description of error returned by try_parse function.

Variables
constexpr std::size_t	N = std::numeric_limits<std::size_t>::max()
	A special marker that means infinite repetitions.

Typedef Documentation

result_wrapper_for_t

template<typename T>

using restinio::easy_parser::result_wrapper_for_t = typename result_wrapper_for<T>::type

Definition at line 253 of file easy_parser.hpp.

Enumeration Type Documentation

error_reason_t

enum class restinio::easy_parser::error_reason_t

strong

Reason of parsing error.

Since

v.0.6.1

Enumerator
unexpected_character	Unexpected character is found in the input.
unexpected_eof	Unexpected end of input is encontered when some character expected.
no_appropriate_alternative	None of alternatives was found in the input.
pattern_not_found	Required pattern is not found in the input.
unconsumed_input	There are some unconsumed non-whitespace characters in the input after the completion of parsing.
illegal_value_found	Illegal value was found in the input. Since v.0.6.2
force_only_this_alternative_failed	A failure of parsing an alternative marked as "force only this alternative". This error code is intended for internal use for the implementation of alternatives() and force_only_this_alternative() stuff. This error tells the parser that other alternatives should not be checked and the parsing of the whole alternatives clause should failed too. Since v.0.6.7

Definition at line 54 of file easy_parser.hpp.

Function Documentation

alternatives()

template<typename... Clauses>

auto restinio::easy_parser::alternatives ( Clauses &&... clauses )

nodiscard

A factory function to create an alternatives clause.

Usage example:

produce<std::string>(
    alternatives(
        sequence(symbol('v'), symbol('='), token_p() >> as_result()),
        sequence(symbol('T'), symbol('/'), token_p() >> as_result())
    )
);

Please note the usage of sequence() inside the call to alternatives().

Template Parameters

Clauses

the list of clauses to be used as alternatives.

Since

v.0.6.1

Definition at line 3598 of file easy_parser.hpp.

and_clause()

template<typename... Clauses>

auto restinio::easy_parser::and_clause ( Clauses &&... clauses )

nodiscard

A factory function to create an and_clause.

Usage example:

produce<std::pair<std::string, std::string>>(
    token_p() >> &std::pair<std::string, std::string>::first,
    symbol(' '),
    token_p() >> &std::pair<std::string, std::string>::second
    and_clause(symbol(','), maybe(symbol(' ')), token_p() >> skip())
);

this expression corresponds the following rule:

T := token SP token &(',' [' '] token)

Template Parameters

Clauses

the list of clauses to be used as sequence to be checked.

Since

v.0.6.1

Definition at line 3721 of file easy_parser.hpp.

any_symbol_if_not_p()

auto restinio::easy_parser::any_symbol_if_not_p ( char sentinel )

inlinenodiscardnoexcept

A factory function to create a any_symbol_if_not_producer.

Returns

a producer that expects any character except sentinel in the input stream and returns it if that character is found.

Since

v.0.6.6

Definition at line 3976 of file easy_parser.hpp.

any_symbol_p()

auto restinio::easy_parser::any_symbol_p ( )

inlinenodiscardnoexcept

A factory function to create an any_symbol_producer.

Returns

a producer that expects any symbol in the input stream and returns it.

Since

v.0.6.6

Definition at line 3940 of file easy_parser.hpp.

as_result()

auto restinio::easy_parser::as_result ( )

inlinenodiscardnoexcept

A factory function to create a as_result_consumer.

Usage example:

produce<std::string>(
    symbol('v'),
    symbol('='),
    token_p() >> as_result(),
    symbol('.')
);

Since

v.0.6.1

Definition at line 4453 of file easy_parser.hpp.

caseless_exact() [1/2]

template<std::size_t Size>

auto restinio::easy_parser::caseless_exact ( const char(&) fragment[Size] )

nodiscard

A factory function that creates an instance of caseless_exact_fragment clause.

Usage example:

produce<std::string>(caseless_exact("version="), token() >> as_result());

Attention

This version is dedicated to be used with string literals. Because of that the last byte from a literal will be ignored (it's assumed that this byte contains zero). But this behavior would lead to unexpected results in such cases:

const char prefix[]{ 'v', 'e', 'r', 's', 'i', 'o', 'n', '=' };
 
produce<std::string>(caseless_exact(prefix), token() >> as_result());

because the last byte with value '=' will be ignored by exact_producer. To avoid such behavior string_view_t should be used explicitely:

produce<std::string>(caseless_exact(string_view_t{prefix}), token() >> as_result());

Since

v.0.6.9

Definition at line 4983 of file easy_parser.hpp.

caseless_exact() [2/2]

auto restinio::easy_parser::caseless_exact ( string_view_t fragment )

inlinenodiscard

A factory function that creates an instance of caseless_exact_fragment clause.

Usage example:

produce<std::string>(caseless_exact("version="), token() >> as_result());

Since

v.0.6.9

Definition at line 4945 of file easy_parser.hpp.

caseless_exact_p() [1/2]

template<std::size_t Size>

auto restinio::easy_parser::caseless_exact_p ( const char(&) fragment[Size] )

nodiscard

A factory function that creates an instance of caseless_exact_fragment_producer.

Usage example:

produce<std::string>(
    alternatives(
        caseless_exact_p("pro") >> just_result("Professional"),
        caseless_exact_p("con") >> just_result("Consumer")
    )
);

Attention

This version is dedicated to be used with string literals. Because of that the last byte from a literal will be ignored (it's assumed that this byte contains zero). But this behavior would lead to unexpected results in such cases:

const char prefix[]{ 'h', 'e', 'l', 'l', 'o' };
 
produce<std::string>(caseless_exact_p(prefix) >> just_result("Hi!"));

because the last byte with value 'o' will be ignored by exact_producer. To avoid such behavior string_view_t should be used explicitely:

produce<std::string>(caseless_exact_p(string_view_t{prefix})
        >> just_result("Hi!"));

Since

v.0.6.9

Definition at line 4924 of file easy_parser.hpp.

caseless_exact_p() [2/2]

auto restinio::easy_parser::caseless_exact_p ( string_view_t fragment )

inlinenodiscard

A factory function that creates an instance of caseless_exact_fragment_producer.

Usage example:

produce<std::string>(
    alternatives(
        caseless_exact_p("pro") >> just_result("Professional"),
        caseless_exact_p("con") >> just_result("Consumer")
    )
);

Since

v.0.6.9

Definition at line 4880 of file easy_parser.hpp.

caseless_symbol()

auto restinio::easy_parser::caseless_symbol ( char expected )

inlinenodiscardnoexcept

A factory function to create a clause that expects the speficied symbol, extracts it and then skips it.

This clause performs caseless comparison of characters.

The call to caseless_symbol('a') function is an equivalent of:

caseless_symbol_p('a') >> skip()

Since

v.0.6.6

Definition at line 4058 of file easy_parser.hpp.

caseless_symbol_p()

auto restinio::easy_parser::caseless_symbol_p ( char expected )

inlinenodiscardnoexcept

A factory function to create a caseless_symbol_producer.

This producer performs caseless comparison of characters.

Returns

a producer that expects expected in the input stream and returns it if that character is found.

Since

v.0.6.6

Definition at line 3996 of file easy_parser.hpp.

convert()

template<typename Converter>

auto restinio::easy_parser::convert ( Converter && converter )

nodiscard

A factory function to create convert_transformer.

Usage example:

// Parser for:
// size       := DIGIT+ [multiplier]
// multiplier := ('b'|'B') | ('k'|'K') | ('m'|'M')
struct tmp_size { std::uint32_t c_{1u}; std::uint32_t m_{1u}; };
auto size_producer = produce<std::uint64_t>(
    produce<tmp_size>(
        non_negative_decimal_number_p<std::uint32_t>() >> &tmp_size::c_,
        maybe(
            produce<std::uint32_t>(
                alternatives(
                    caseless_symbol_p('b') >> just_result(1u),
                    caseless_symbol_p('k') >> just_result(1024u),
                    caseless_symbol_p('m') >> just_result(1024u*1024u)
                )
            ) >> &tmp_size::m_
        )
    )
    >> convert( [](const tmp_size & ts) { return std::uint64_t{ts.c_} * ts.m_; } )
    >> as_result()
);

Note

Since v.0.6.11 a conversion function can have two formats. The first one is:

result_type fn(input_type source_val);

for example:

convert([](const std::string & from) -> int {...})

in that case a conversion error can only be reported via an exception. The second one is:

expected_t<result_type, error_reason_t> fn(input_type source_val);

for example:

convert([](const std::string & from) -> expected_t<int, error_reason_t> {...})

in that case a converion error can be reported also via returning value. For example, let's assume that in the code snippet shown above the result value should be greater than 0. It can be checked in the conversion function that way:

convert([](const tmp_size & ts) -> expected_t<std::uint64_t, error_reason_t> {
    const auto r = std::uint64_t{ts.c_} * ts.m_;
    if( r )
        return r;
    else
        return make_unexpected(error_reason_t::illegal_value_found);
}

Since

v.0.6.6

Definition at line 4720 of file easy_parser.hpp.

custom_consumer()

template<typename F>

auto restinio::easy_parser::custom_consumer ( F consumer )

nodiscard

A factory function to create a custom_consumer.

Usage example:

class composed_value {
    std::string name_;
    std::string value_;
public:
    composed_value() = default;
 
    void set_name(std::string name) { name_ = std::move(name); }
    void set_value(std::string value) { value_ = std::move(value); }
    ...
};
produce<composed_value>(
    token_p() >> custom_consumer(
        [](composed_value & to, std::string && what) {
            to.set_name(std::move(what));
        } ),
    symbol('='),
    token_p() >> custom_consumer(
        [](composed_value & to, std::string && what) {
            to.set_value(std::move(what));
        } ),
    symbol('.')
);

Note

A custom consumer should be a function/lambda/function objects with the following prototype:

void(Target_Type & destination, Value && value);

Since

v.0.6.1

Definition at line 4499 of file easy_parser.hpp.

decimal_number_p() [1/2]

template<typename T>

auto restinio::easy_parser::decimal_number_p ( )

inlinenodiscardnoexcept

A factory function to create a decimal_number_producer.

Parses numbers in the form:

number := [sign] DIGIT+
sign   := '-' | '+'

Note

This parser consumes all digits until the first non-digit symbol will be found in the input. It means that in the case of -1111someword the leading minus sign and thefirst four digits (e.g. -1111) will be extracted from the input and the remaining part (e.g. someword) won't be consumed by this parser.

Attention

Can be used only for singed number types (e.g. short, int, long, std::int32_t and so on).

Returns

a producer that expects a decimal number in the input stream and returns it if a number is found.

Since

v.0.6.6

Definition at line 4370 of file easy_parser.hpp.

decimal_number_p() [2/2]

template<typename T>

auto restinio::easy_parser::decimal_number_p ( digits_to_consume_t digits_limit )

inlinenodiscardnoexcept

A factory function to create a decimal_number_producer.

Parses numbers in the form:

number := [sign] DIGIT+
sign   := '-' | '+'

Note

This parser consumes a number of digits with respect to digits_limit. The leading sign (if present) is not added to a number of extracted digits.

Usage example:

using namespace restinio::easy_parser;
 
struct compound_number {
 short prefix_;
 int suffix_;
};
 
auto parse = produce<compound_number>(
 decimal_number_p<short>(expected_digits(4))
     >> &compound_number::prefix_,
 decimal_number_p<int>(expected_digits(7, 12))
     >> &compound_number::suffix_
);

Attention

Can be used only for singed number types (e.g. short, int, long, std::int32_t and so on).

Returns

a producer that expects a decimal number in the input stream and returns it if a number is found.

Since

v.0.6.6

Definition at line 4423 of file easy_parser.hpp.

digit()

auto restinio::easy_parser::digit ( )

inlinenodiscardnoexcept

A factory function to create a clause that expects a decimal digit, extracts it and then skips it.

The call to digit() function is an equivalent of:

digit_p() >> skip()

Since

v.0.6.6

Definition at line 4157 of file easy_parser.hpp.

digit_p()

auto restinio::easy_parser::digit_p ( )

inlinenodiscardnoexcept

A factory function to create a digit_producer.

Returns

a producer that expects a decimal digit in the input stream and returns it if a decimal digit is found.

Since

v.0.6.1

Definition at line 4136 of file easy_parser.hpp.

exact() [1/2]

template<std::size_t Size>

auto restinio::easy_parser::exact ( const char(&) fragment[Size] )

nodiscard

A factory function that creates an instance of exact_fragment clause.

Usage example:

produce<std::string>(exact("version="), token() >> as_result());

Attention

This version is dedicated to be used with string literals. Because of that the last byte from a literal will be ignored (it's assumed that this byte contains zero). But this behavior would lead to unexpected results in such cases:

const char prefix[]{ 'v', 'e', 'r', 's', 'i', 'o', 'n', '=' };
 
produce<std::string>(exact(prefix), token() >> as_result());

because the last byte with value '=' will be ignored by exact_producer. To avoid such behavior string_view_t should be used explicitely:

produce<std::string>(exact(string_view_t{prefix}),  token() >> as_result());

Since

v.0.6.6

Definition at line 4854 of file easy_parser.hpp.

exact() [2/2]

auto restinio::easy_parser::exact ( string_view_t fragment )

inlinenodiscard

A factory function that creates an instance of exact_fragment clause.

Usage example:

produce<std::string>(exact("version="), token() >> as_result());

Since

v.0.6.6

Definition at line 4816 of file easy_parser.hpp.

exact_p() [1/2]

template<std::size_t Size>

auto restinio::easy_parser::exact_p ( const char(&) fragment[Size] )

nodiscard

A factory function that creates an instance of exact_fragment_producer.

Usage example:

produce<std::string>(
    alternatives(
        exact_p("pro") >> just_result("Professional"),
        exact_p("con") >> just_result("Consumer")
    )
);

Attention

This version is dedicated to be used with string literals. Because of that the last byte from a literal will be ignored (it's assumed that this byte contains zero). But this behavior would lead to unexpected results in such cases:

const char prefix[]{ 'h', 'e', 'l', 'l', 'o' };
 
produce<std::string>(exact_p(prefix) >> just_result("Hi!"));

because the last byte with value 'o' will be ignored by exact_producer. To avoid such behavior string_view_t should be used explicitely:

produce<std::string>(exact_p(string_view_t{prefix})
        >> just_result("Hi!"));

Since

v.0.6.6

Definition at line 4795 of file easy_parser.hpp.

exact_p() [2/2]

auto restinio::easy_parser::exact_p ( string_view_t fragment )

inlinenodiscard

A factory function that creates an instance of exact_fragment_producer.

Usage example:

produce<std::string>(
    alternatives(
        exact_p("pro") >> just_result("Professional"),
        exact_p("con") >> just_result("Consumer")
    )
);

Since

v.0.6.6

Definition at line 4751 of file easy_parser.hpp.

expected_digits() [1/2]

digits_to_consume_t restinio::easy_parser::expected_digits ( digits_to_consume_t::underlying_int_t min, digits_to_consume_t::underlying_int_t max )

inlinenodiscardconstexprnoexcept

Create a limit for number of digits to be extracted.

Makes a limit where min and max are specified separately.

Usage example:

using namespace restinio::easy_parser;
 
auto ten_digits_int32_p = decimal_number_p<std::int32_t>(expected_digits(1, 10));

Since

v.0.6.6

Definition at line 573 of file easy_parser.hpp.

expected_digits() [2/2]

digits_to_consume_t restinio::easy_parser::expected_digits ( digits_to_consume_t::underlying_int_t total )

inlinenodiscardconstexprnoexcept

Create a limit for number of digits to be extracted.

Makes a limit where min==max and both are equal to total.

Usage example:

using namespace restinio::easy_parser;
 
auto x_uint32_p = hexadecimal_number_p<std::uint32_t>(expected_digits(8));

Since

v.0.6.6

Definition at line 552 of file easy_parser.hpp.

force_only_this_alternative()

template<typename... Clauses>

auto restinio::easy_parser::force_only_this_alternative ( Clauses &&... clauses )

nodiscard

An alternative that should be parsed correctly or the parsing of the whole alternatives clause should fail.

This special clause is intended to be used to avoid mistakes in grammars like that:

v = "key" '=' token
  | token '=' 1*VCHAR

If that grammar will be used for parsing a sentence like "key=123" then the second alternative will be selected. It's because the parsing of rule "key" '=' token fails at 123 and the second alternative will be tried. And "key" will be recognized as a token.

Before v.0.6.7 this mistake can be avoided by using rules like those:

v = "key" '=' token
  | !"key" token '=' 1*VCHAR

Since v.0.6.7 this mistake can be avoided by using force_only_this_alternative() function:

alternatives(
 sequence(
     exact("key"),
     force_only_this_alternative(
         symbol('='),
         token() >> skip()
     )
 ),
 sequence(
     token() >> skip(),
     symbol('='),
     repeat(1, N, vchar_symbol_p() >> skip())
 )
);

Since

v.0.6.7

Definition at line 3824 of file easy_parser.hpp.

hexadecimal_number_p() [1/2]

template<typename T>

auto restinio::easy_parser::hexadecimal_number_p ( )

inlinenodiscardnoexcept

A factory function to create a hexadecimal_number_producer.

Note

This parser consumes all digits until the first non-digit symbol will be found in the input. It means that in the case of 1111someword the first four digits (e.g. 1111) will be extracted from the input and the remaining part (e.g. someword) won't be consumed by this parser.

Attention

T should be an unsigned type.

Returns

a producer that expects a positive hexadecimal number in the input stream and returns it if a number is found.

Since

v.0.6.6

Definition at line 4290 of file easy_parser.hpp.

hexadecimal_number_p() [2/2]

template<typename T>

auto restinio::easy_parser::hexadecimal_number_p ( digits_to_consume_t digits_limit )

inlinenodiscardnoexcept

A factory function to create a hexadecimal_number_producer.

Note

This parser consumes a number of digits with respect to digits_limit.

Usage example:

using namespace restinio::easy_parser;
 
struct compound_number {
    short prefix_;
    int suffix_;
};
 
auto parse = produce<compound_number>(
    hexadecimal_number_p<short>(expected_digits(4))
        >> &compound_number::prefix_,
    hexadecimal_number_p<int>(expected_digits(7, 12))
        >> &compound_number::suffix_
);

Attention

T should be an unsigned type.

Returns

a producer that expects a positive hexadecimal number in the input stream and returns it if a number is found.

Since

v.0.6.6

Definition at line 4332 of file easy_parser.hpp.

hexdigit()

auto restinio::easy_parser::hexdigit ( )

inlinenodiscardnoexcept

A factory function to create a clause that expects a hexadecimal digit, extracts it and then skips it.

The call to hexdigit() function is an equivalent of:

hexdigit_p() >> skip()

Since

v.0.6.6

Definition at line 4196 of file easy_parser.hpp.

hexdigit_p()

auto restinio::easy_parser::hexdigit_p ( )

inlinenodiscardnoexcept

A factory function to create a hexdigit_producer.

Returns

a producer that expects a hexadecimal digit in the input stream and returns it if a hexadecimal digit is found.

Since

v.0.6.6

Definition at line 4175 of file easy_parser.hpp.

just()

template<typename T>

auto restinio::easy_parser::just ( T value )

nodiscardnoexcept

A special transformer that replaces the produced value by a value specified by a user.

Usage example:

produce<unsigned int>(
    alternatives(
        symbol('b') >> just(1u) >> as_result(),
        symbol('k') >> just(1024u) >> as_result(),
        symbol('m') >> just(1024u*1024u) >> as_result()
    )
);

Since

v.0.6.6

Definition at line 4618 of file easy_parser.hpp.

just_result()

template<typename T>

auto restinio::easy_parser::just_result ( T value )

nodiscardnoexcept

A special consumer that replaces the produced value by a value specified by a user and sets that user-specified value as the result.

Usage example:

produce<unsigned int>(
    alternatives(
        symbol('b') >> just_result(1u),
        symbol('k') >> just_result(1024u),
        symbol('m') >> just_result(1024u*1024u)
    )
);

Since

v.0.6.6

Definition at line 4647 of file easy_parser.hpp.

make_error_description()

std::string restinio::easy_parser::make_error_description ( const parse_error_t & error, string_view_t from )

inlinenodiscard

Make textual description of error returned by try_parse function.

Note

The format of textual description is not specified and can be changed in some future versions without notice.

Usage example:

const char * content = "first,Second;Third;Four";
const auto tokens = try_parse(
    content,
    produce<std::vector<std::string>>(
        token_p() >> to_lower() >> to_container(),
        repeat( 0, N,
            alternatives(symbol(','), symbol(';')),
            token_p() >> to_lower() >> to_container()
        )
    )
);
if(tokens)
{
    for(const auto & v: *tokens)
        std::cout << v << std::endl;
}
else
    std::cerr << make_error_description(tokens.error(), content) << std::endl;

Since

v.0.6.1

Definition at line 5086 of file easy_parser.hpp.

maybe()

template<typename... Clauses>

auto restinio::easy_parser::maybe ( Clauses &&... clauses )

nodiscard

A factory function to create an optional clause.

Usage example:

produce<std::pair<std::string, std::string>>(
    token_p() >> &std::pair<std::string, std::string>::first,
    maybe(
        symbol('='),
        token_p() >> &std::pair<std::string, std::string>::second
    )
);

Template Parameters

Clauses

the list of clauses to be used as optional sequence.

Since

v.0.6.1

Definition at line 3637 of file easy_parser.hpp.

non_negative_decimal_number_p() [1/2]

template<typename T>

auto restinio::easy_parser::non_negative_decimal_number_p ( )

inlinenodiscardnoexcept

A factory function to create a non_negative_decimal_number_producer.

Note

This parser consumes all digits until the first non-digit symbol will be found in the input. It means that in the case of 1111someword the first four digits (e.g. 1111) will be extracted from the input and the remaining part (e.g. someword) won't be consumed by this parser.

Returns

a producer that expects a positive decimal number in the input stream and returns it if a number is found.

Since

v.0.6.2

Definition at line 4221 of file easy_parser.hpp.

non_negative_decimal_number_p() [2/2]

template<typename T>

auto restinio::easy_parser::non_negative_decimal_number_p ( digits_to_consume_t digits_limit )

inlinenodiscardnoexcept

A factory function to create a non_negative_decimal_number_producer.

Note

This parser consumes a number of digits with respect to digits_limit.

Usage example:

using namespace restinio::easy_parser;
 
struct compound_number {
    short prefix_;
    int suffix_;
};
 
auto parse = produce<compound_number>(
    non_negative_decimal_number_p<short>(expected_digits(2, 5))
        >> &compound_number::prefix_,
    non_negative_decimal_number_p<int>(expected_digits(7, 12))
        >> &compound_number::suffix_
);

Returns

a producer that expects a positive decimal number in the input stream and returns it if a number is found.

Since

v.0.6.2

Definition at line 4260 of file easy_parser.hpp.

not_clause()

template<typename... Clauses>

auto restinio::easy_parser::not_clause ( Clauses &&... clauses )

nodiscard

A factory function to create a not_clause.

Usage example:

produce<std::pair<std::string, std::string>>(
    token_p() >> &std::pair<std::string, std::string>::first,
    symbol(' '),
    token_p() >> &std::pair<std::string, std::string>::second
    not_clause(symbol('.'))
);

this expression corresponds the following rule:

T := token SP token !'.'

Template Parameters

Clauses

the list of clauses to be used as sequence to be checked.

Since

v.0.6.1

Definition at line 3679 of file easy_parser.hpp.

produce()

template<typename Target_Type, typename... Clauses>

auto restinio::easy_parser::produce ( Clauses &&... clauses )

nodiscard

A factory function to create a producer that creates an instance of the target type by using specified clauses.

Usage example:

produce<std::string>(symbol('v'), symbol('='), token_p() >> as_result());

Template Parameters

Target_Type	the type of value to be produced.
Clauses	the list of clauses to be used for a new value.

Since

v.0.6.1

Definition at line 3557 of file easy_parser.hpp.

repeat()

template<typename... Clauses>

auto restinio::easy_parser::repeat ( std::size_t min_occurences, std::size_t max_occurences, Clauses &&... clauses )

nodiscard

A factory function to create repetitor of subclauses.

Usage example:

using str_pair = std::pair<std::string, std::string>;
produce<std::vector<str_pair>>(
    produce<str_pair>(
        token_p() >> &str_pair::first,
        symbol('='),
        token_p() >> &str_pair::second
    ) >> to_container(),
    repeat(0, N,
        symbol(','),
        produce<str_pair>(
            token_p() >> &str_pair::first,
            symbol('='),
            token_p() >> &str_pair::second
        ) >> to_container()
    )
);

this expression corresponds to the following rule:

 T := token '=' token *(',' token '=' token)

Template Parameters

Clauses

the list of clauses to be used as the sequence to be repeated.

Since

v.0.6.1

Parameters

min_occurences	Minimal occurences of the sequences in the repetition.
max_occurences	Maximal occurences of the sequences in the repetition.

Note

The repetition will be stopped when that numer of repetitions will be reached.

Parameters

clauses

The sequence of clauses to be repeated.

Definition at line 3879 of file easy_parser.hpp.

sequence()

template<typename... Clauses>

auto restinio::easy_parser::sequence ( Clauses &&... clauses )

nodiscard

A factory function to create a sequence of subclauses.

Usage example:

produce<std::string>(
    alternatives(
        sequence(symbol('v'), symbol('='), token_p() >> as_result()),
        sequence(symbol('T'), symbol('/'), token_p() >> as_result())
    )
);

Please note the usage of sequence() inside the call to alternatives().

Template Parameters

Clauses

the list of clauses to be used as the sequence.

Since

v.0.6.1

Definition at line 3761 of file easy_parser.hpp.

skip()

auto restinio::easy_parser::skip ( )

inlinenodiscardnoexcept

A factory function to create a skip_consumer.

Usage example:

produce<std::string>(
    token_p() >> as_result(),
    not_clause(symbol('='), token_p() >> skip())
);

Since

v.0.6.1

Definition at line 3925 of file easy_parser.hpp.

space()

auto restinio::easy_parser::space ( )

inlinenodiscardnoexcept

A factory function to create a clause that expects a space, extracts it and then skips it.

The call to space() function is an equivalent of:

space_p() >> skip()

Since

v.0.6.4

Definition at line 4118 of file easy_parser.hpp.

space_p()

auto restinio::easy_parser::space_p ( )

inlinenodiscardnoexcept

A factory function to create a space_producer.

Returns

a producer that expects space character in the input stream and returns it if that character is found.

Since

v.0.6.4

Definition at line 4097 of file easy_parser.hpp.

symbol()

auto restinio::easy_parser::symbol ( char expected )

inlinenodiscardnoexcept

A factory function to create a clause that expects the speficied symbol, extracts it and then skips it.

The call to symbol('a') function is an equivalent of:

symbol_p('a') >> skip()

Since

v.0.6.1

Definition at line 4035 of file easy_parser.hpp.

symbol_from_range()

auto restinio::easy_parser::symbol_from_range ( char left, char right )

inlinenodiscardnoexcept

A factory function to create a clause that expects a symbol from specified range, extracts it and then skips it.

The call to symbol_from_range('a', 'z') function is an equivalent of:

symbol_from_range_p('a', 'z') >> skip()

Since

v.0.6.9

Definition at line 4079 of file easy_parser.hpp.

symbol_from_range_p()

auto restinio::easy_parser::symbol_from_range_p ( char left, char right )

inlinenodiscardnoexcept

A factory function to create a symbol_from_range_producer.

Returns

a producer that expects a symbol from [left, right] range in the input stream and returns it if that character is found.

Since

v.0.6.9

Definition at line 4014 of file easy_parser.hpp.

symbol_p()

auto restinio::easy_parser::symbol_p ( char expected )

inlinenodiscardnoexcept

A factory function to create a symbol_producer.

Returns

a producer that expects expected in the input stream and returns it if that character is found.

Since

v.0.6.1

Definition at line 3958 of file easy_parser.hpp.

to_container()

auto restinio::easy_parser::to_container ( )

inlinenodiscard

A factory function to create a to_container_consumer.

Usage example:

using str_pair = std::pair<std::string, std::string>;
produce<std::vector<str_pair>>(
    produce<str_pair>(
        token_p() >> &str_pair::first,
        symbol('='),
        token_p() >> &str_pair::second
    ) >> to_container(),
    repeat(0, N,
        symbol(','),
        produce<str_pair>(
            token_p() >> &str_pair::first,
            symbol('='),
            token_p() >> &str_pair::second
        ) >> to_container()
    )
);

Since

v.0.6.1

Definition at line 4566 of file easy_parser.hpp.

to_lower()

auto restinio::easy_parser::to_lower ( )

inlinenodiscardnoexcept

A factory function to create a to_lower_transformer.

Usage example:

produce<std::string>(
    symbol('T'), symbol(':'),
    token_p() >> to_lower() >> as_result()
);
...
// Since v.0.6.6 to_lower can also be used for a single character.
produce<char>(
    exact("I="), any_symbol_p() >> to_lower() >> as_result() );

Since

v.0.6.1

Definition at line 4593 of file easy_parser.hpp.

try_parse()

template<typename Producer>

expected_t< typename Producer::result_type, parse_error_t > restinio::easy_parser::try_parse ( string_view_t from, Producer producer )

nodiscard

Perform the parsing of the specified content by using specified value producer.

Note

The whole content of from should be consumed. There can be whitespace remaining in @from after the return from Producer::try_parser. But if there will be some non-whitespace symbol the failure will be reported. (As a side note: since v.0.6.7 all trailing spaces are removed from @from before the parsing starts.)

Usage example

const auto tokens = try_parse(
    "first,Second;Third;Four",
    produce<std::vector<std::string>>(
        token_p() >> to_lower() >> to_container(),
        repeat( 0, N,
            alternatives(symbol(','), symbol(';')),
            token_p() >> to_lower() >> to_container()
        )
    )
);
if(tokens)
    for(const auto & v: *tokens)
        std::cout << v << std::endl;

Since

v.0.6.1

Definition at line 5025 of file easy_parser.hpp.

Variable Documentation

N

std::size_t restinio::easy_parser::N = std::numeric_limits<std::size_t>::max()

constexpr

A special marker that means infinite repetitions.

Since

v.0.6.1

Definition at line 458 of file easy_parser.hpp.