basic_csv_options.md

jsoncons::csv::basic_csv_options

#include <jsoncons_ext/csv/csv_options.hpp>

template< 
    class CharT
> class basic_csv_options;

Specifies options for reading and writing CSV data.

Option	Reading	Writing
nan_to_str	Substitute string with NaN, if enabled	Sets a string replacement for NaN when writing JSON
inf_to_str	Substitute string with infinity, if enabled	Sets a string replacement for infinity when writing JSON
neginf_to_str	Substitute string with negative infinity, if enabled	Sets a string replacement for negative infinity when writing JSON
nan_to_num		Sets a number replacement for NaN when writing JSON
inf_to_num		Sets a number replacement for Infinity when writing JSON
neginf_to_num		Sets a number replacement for Negative Infinity when writing JSON
line_delimiter	Not used. When reading, the parser accepts \n, \r and \r\n.	An end-of-line string that marks the end of a row. Default is \n.
field_delimiter	A character that indicates the end of a field. Default is ,.	Character to separate values.
subfield_delimiter	A character that indicates the end of a single value in a multi-valued field. Default is no multi-valued fields.	Character to write between items in an array value.
quote_char	A character to quote fields. Default is the double quote character "	A character to quote fields.
quote_escape_char	A character to escape quote characters occuring inside quoted fields. The default is the double quote character (i.e. the quote character is doubled).	Character to escape quote characters occurring inside quoted fields.
quote_style		Indicates what quote_style to use when quoting fields. Default is minimal.
column_names	Use these column names when reading the file.	Write these column names to the header line.
header_lines	Number of header lines in the CSV text. Defaults to 1 if assume_header is true, otherwise 0
assume_header	Assume first row in file is header, use field names to construct objects. Default is false.
skip_header	Skip the first (header) line of input. Default is false.
ignore_empty_values	Do not read CSV fields that have empty values. Default is false.
ignore_empty_lines	If set to true, all lines in the file that are empty (apart from record delimiter characters) are ignored. To ignore lines with only spaces or tabs, set trim to true. Default is true.
trim_leading	Trim leading whitespace. Default is false.
trim_trailing	Trim trailing whitespace. Default is false.
trim	Trim both leading and trailing whitespace. Default is false.
trim_leading_inside_quotes	Trim leading whitespace inside quote characters. Default is false.
trim_trailing_inside_quotes	Trim trailing whitespace inside quote characters. Default is false.
trim_inside_quotes	Trim both leading and trailing whitespace inside quote characters. Default is false.
unquoted_empty_value_is_null	Replace empty field with json null value. Default is false.
infer_types	Infer null, true, false, integers and floating point values in the CSV source. Default is true.
lossless_number	If set to true, parse numbers with exponents and fractional parts as strings with semantic tagging semantic_tag::bigdec. Default is false.
comment_starter	Character to comment out a line, must be at column 1. Default is no comments.
mapping_kind	Indicates what mapping kind to use when parsing a CSV file into a basic_json. If assume_header is true or column_names is not empty, defaults to csv_mapping_kind::n_objects, otherwise csv_mapping_kind::n_rows.
max_lines	Maximum number of lines to read. Default is unlimited.
column_types	A comma separated list of data types corresponding to the columns in the file. The following data types are supported: string, integer, float and boolean. Example: "bool,float,string"}
column_defaults	A comma separated list of strings containing default json values corresponding to the columns in the file. Example: "false,0.0,""""
float_format		Overrides floating point format when serializing to CSV. The default is float_chars_format::general.
precision		Overrides floating point precision when serializing csv from json. The default is shortest representation.

Aliases for common character types are provided:

Type	Definition
csv_options	basic_csv_options<char>
wcsv_options	basic_csv_options<wchar_t>

Member type	Definition
char_type	CharT
string_type	std::basic_string<CharT>

Constructors

basic_csv_options()

Constructs a basic_csv_options with default values.

basic_csv_options(const basic_csv_options& other)

Copy constructor.

basic_csv_options(basic_csv_options&& other)

Move constructor.

Modifiers

basic_json_options& nan_to_str(const string_type& value, bool enable_inverse = true); 

Sets a string replacement for NaN when writing JSON, and indicate whether it is also to be used when reading JSON.

basic_json_options& inf_to_str(const string_type& value, bool enable_inverse = true); 

Sets a string replacement for infinity when writing JSON, and indicate whether it is also to be used when reading JSON.

basic_json_options& neginf_to_str(const string_type& value, bool enable_inverse = true); (4)

Sets a string replacement for negative infinity when writing JSON, and indicate whether it is also to be used when reading JSON.

basic_json_options& nan_to_num(const string_type& value); 

Sets a number replacement for NaN when writing JSON

basic_json_options& inf_to_num(const string_type& value); 

Sets a number replacement for Infinity when writing JSON

basic_json_options& neginf_to_num(const string_type& value); 

Sets a number replacement for Negative Infinity when writing JSON

basic_csv_options& float_format(float_chars_format value);

Overrides floating point format when serializing to CSV. The default is float_chars_format::general.

basic_csv_options& precision(int8_t value);

Overrides floating point precision when serializing csv from json. The default is shortest representation.

basic_csv_options& header_lines(std::size_t value);

Number of header lines in the CSV text. Defaults to 1 if assume_header is true, otherwise 0

basic_csv_options& assume_header(bool value);

Assume first row in file is header, use field names to construct objects. Default is false.

basic_csv_options& ignore_empty_values(bool value);

Do not read CSV fields that have empty values. Default is false.

basic_csv_options& ignore_empty_lines(bool value);

If set to true, all lines in the file that are empty (apart from record delimiter characters) are ignored. To ignore lines with only spaces or tabs, set trim to true. Default is true.

basic_csv_options& trim_leading(bool value);

Trim leading whitespace. Default is false.

basic_csv_options& trim_trailing(bool value);

Trim trailing whitespace. Default is false.

basic_csv_options& trim(bool value);

Trim both leading and trailing whitespace. Default is false.

basic_csv_options& trim_leading_inside_quotes(bool value);

Trim leading whitespace inside quote characters. Default is false.

basic_csv_options& trim_trailing_inside_quotes(bool value);

Trim trailing whitespace inside quote characters. Default is false.

basic_csv_options& trim_inside_quotes(bool value);

Trim both leading and trailing whitespace inside quote characters. Default is false.

basic_csv_options& unquoted_empty_value_is_null(bool value);

Replace empty field with json null value. Default is false.

basic_csv_options& column_names(const string_type& value);

A comma separated list of names corresponding to the fields in the file. Example: "bool-field,float-field,string-field"

basic_csv_options& column_types(const string_type& value);

A comma separated list of data types corresponding to the columns in the file. The following data types are supported: string, integer, float and boolean. Example: "bool,float,string"}

basic_csv_options& column_defaults(const string_type& value);

A comma separated list of strings containing default json values corresponding to the columns in the file. Example: "false,0.0,""""

basic_csv_options& field_delimiter(char_type value);

A delimiter character that indicates the end of a field. Default is ,

basic_csv_options& subfield_delimiter(char_type value);

A delimiter character that indicates the end of a single value in a multi-valued field. Default is no multi-valued fields.

basic_csv_options& line_delimiter(string_type value);

String to write between records. Default is \n.

basic_csv_options& quote_char(char_type value);

Quote character. Default is quote character "

basic_csv_options& infer_types(bool value);

Infer null, true, false, integers and floating point values in the CSV source. Default is true.

basic_csv_options& lossless_number(bool value); 

If set to true, parse numbers with exponents and fractional parts as strings with semantic tagging semantic_tag::bigdec. Default is false.

basic_csv_options& quote_escape_char(char_type value);

Character to escape quote character (by default the quote character is doubled). Default is quote character ".

basic_csv_options& comment_starter(char_type value);

Character to comment out a line, must be at column 1. Default is no comments.

basic_csv_options& quote_style(quote_style_kind value);

Indicates what quote_style to use when quoting fields. Default is minimal.

basic_csv_options& mapping_kind(csv_mapping_kind value);

Indicates what mapping kind to use when parsing a CSV file into a basic_json. If assume_header is true or column_names is not empty, defaults to csv_mapping_kind::n_rows, otherwise csv_mapping_kind::n_columns.

basic_csv_options& max_lines(std::size_t value);

Maximum number of lines to read. Default is unlimited.