std.csv

Implements functionality to read Comma Separated Values and its variants
from an input range of dchar.
Comma Separated Values provide a simple means to transfer and store
tabular data. It has been common for programs to use their own
variant of the CSV format. This parser will loosely follow the
RFC-4180. CSV input should adhere
to the following criteria (differences from RFC-4180 in parentheses):
Example:
-------
import std.algorithm;
import std.array;
import std.csv;
import std.stdio;
import std.typecons;
void main()
{
auto text = "Joe,Carpenter,300000\nFred,Blacksmith,400000\r\n";
foreach (record; csvReader!(Tuple!(string, string, int))(text))
{
writefln("%s works as a %s and earns $%d per year",
record0, record1, record2);
}
// To read the same string from the file "filename.csv":
auto file = File("filename.csv", "r");
foreach (record;
file.byLine.joiner("\n").csvReader!(Tuple!(string, string, int)))
{
writefln("%s works as a %s and earns $%d per year",
record0, record1, record2);
} }
}
-------
When an input contains a header the Contents can be specified as an
associative array. Passing null to signify that a header is present.
-------
auto text = "Name,Occupation,Salary\r" ~
"Joe,Carpenter,300000\nFred,Blacksmith,400000\r\n";
foreach (record; csvReader!(stringstring)
(text, null))
{
writefln("%s works as a %s and earns $%s per year.",
record"Name", record"Occupation",
record"Salary");
}
// To read the same string from the file "filename.csv":
auto file = File("filename.csv", "r");
foreach (record; csvReader!(stringstring)
(file.byLine.joiner("\n"), null))
{
writefln("%s works as a %s and earns $%s per year.",
record"Name", record"Occupation",
record"Salary");
}
-------
This module allows content to be iterated by record stored in a struct,
class, associative array, or as a range of fields. Upon detection of an
error an CSVException is thrown (can be disabled). csvNextToken has been
made public to allow for attempted recovery.
Disabling exceptions will lift many restrictions specified above. A quote
can appear in a field if the field was not quoted. If in a quoted field any
quote by itself, not at the end of a field, will end processing for that
field. The field is ended when there is no input, even if the quote was not
closed.
See Also
Wikipedia
Comma-separated values
Copyright
Copyright 2011
License
Boost License 1.0.
Authors
Jesse Phillips
Source: std/csv.d

Types 7

Exception containing the row and column for when an exception was thrown.

Numbering of both row and col start at one and corresponds to the location in the file rather than any specified header. Special consideration should be made when there is failure to match the header see HeaderMismatchException for details.

When performing type conversions, ConvException is stored in the next field.

Fields

size_t row

Methods

string toString() @safe pure const

Constructors

this(string msg,  string file =  __FILE__,  size_t line =  __LINE__,
          Throwable next =  null)

this(string msg,  Throwable next,  string file =  __FILE__,
          size_t line =  __LINE__)

this(string msg,  size_t row,  size_t col,  Throwable next =  null,
          string file =  __FILE__,  size_t line =  __LINE__)

classIncompleteCellException : CSVException

Exception thrown when a Token is identified to not be completed: a quote is found in an unquoted field, data continues after a closing quote, or the quoted field was not closed before data was empty.

Fields

dstring partialDataData pulled from input before finding a problem

classHeaderMismatchException : CSVException

Exception thrown under different conditions based on the type of Contents.

Structure, Class, and Associative Array

When a header is provided but a matching column is not found

Other

When a header is provided but a matching column is not found
Order did not match that found in the input

Since a row and column is not meaningful when a column specified by the header is not found in the data, both row and col will be zero. Otherwise row is always one and col is the first instance found in header that occurred before the previous starting at one.

enumMalformed

Determines the behavior for when an error is detected.

Disabling exception will follow these rules:

A quote can appear in a field if the field was not quoted.
If in a quoted field any quote by itself, not at the end of a
field, will end processing for that field.

The field is ended when there is no input, even if the quote was
not closed.

If the given header does not match the order in the input, the
content will return as it is found in the input.

If the given header contains columns not found in the input they
will be ignored.

ignoreNo exceptions are thrown due to incorrect CSV.

throwExceptionUse exceptions when input has incorrect CSV.

private structInput(Range, Malformed ErrorLevel)

Fields

Range range

size_t row

private structCsvReader(Contents, Malformed ErrorLevel, Range, Separator, Header) if (isSomeChar!Separator && isInputRange!Range && is(immutable ElementType!Range == immutable dchar) && isForwardRange!Header && isSomeString!(ElementType!Header))

Fields

Input!(Range, ErrorLevel) * _input

Separator _separator

Separator _quote

size_t[] indices

bool _empty

bool _allowInconsistentDelimiterCount

string[] headerHeader from the input in array form.

Methods

@property auto front()Part of an input range as defined by isInputRange.

bool empty() @property @safe @nogc pure nothrow constPart of an input range as defined by isInputRange.

void popFront()Part of an input range as defined by isInputRange.

private void prime()

Constructors

this(Range input,  Separator delimiter,  Separator quote,
             bool  allowInconsistentDelimiterCount)

Constructor to initialize the input, delimiter and quote for input without a header.

this(Range input,  Header colHeaders,  Separator delimiter,  Separator quote,
             bool  allowInconsistentDelimiterCount)

Constructor to initialize the input, delimiter and quote for input with a header.

private structCsvRecord(Contents, Malformed ErrorLevel, Range, Separator) if (!is(Contents == class) && !is(Contents == struct))

Fields

Input!(Range, ErrorLevel) * _input

Separator _separator

Separator _quote

Contents curContentsoken

typeof(appender!(dchar[])()) _front

bool _empty

bool _allowInconsistentDelimiterCount

size_t[] _popCount

Methods

Contents front() @property @safe purePart of an input range as defined by isInputRange.

bool empty() @property @safe pure nothrow @nogc constPart of an input range as defined by isInputRange.

private bool recordEnd()

void popFront()Part of an input range as defined by isInputRange.

private void prime(size_t skipNum)

private void prime()

Constructors

this(Input!(Range,  ErrorLevel) *  input,  Separator delimiter,
          Separator quote,  size_t[]  indices,
          bool  allowInconsistentDelimiterCount)

Functions 4

auto csvReader(Contents =  string, Malformed ErrorLevel =  Malformed.throwException,  Range,  Separator =  char)(Range input,
                  Separator delimiter =  ',',  Separator quote =  '"',
                  bool  allowInconsistentDelimiterCount =  false) if (isInputRange!Range &&  is(immutable  ElementType!Range ==  immutable  dchar)
     &&  isSomeChar!(Separator)
     && !is(Contents T :  T[U],  U :  string))

Returns an input range for iterating over records found in `input`.

auto csvReader(Contents =  string,
                Malformed ErrorLevel =  Malformed.throwException,
                Range,  Header,  Separator =  char)(Range input,  Header header,
                  Separator delimiter =  ',',  Separator quote =  '"',
                  bool  allowInconsistentDelimiterCount =  false) if (isInputRange!Range &&  is(immutable  ElementType!Range ==  immutable  dchar)
     &&  isSomeChar!(Separator)
     &&  isForwardRange!Header
    &&  isSomeString!(ElementType!Header))

ditto

auto csvReader(Contents =  string,
                Malformed ErrorLevel =  Malformed.throwException,
                Range,  Header,  Separator =  char)(Range input,  Header header,
                  Separator delimiter =  ',',  Separator quote =  '"',
                  bool  allowInconsistentDelimiterCount =  false) if (isInputRange!Range &&  is(immutable  ElementType!Range ==  immutable  dchar)
     &&  isSomeChar!(Separator)
     &&  is(Header :  typeof(null)))

ditto

void csvNextToken(Range,  Malformed ErrorLevel =  Malformed.throwException,
                            Separator,  Output)(ref  Range input,  ref  Output ans,
                            Separator sep,  Separator quote,
                            bool  startQuoted =  false) if (isSomeChar!Separator &&  isInputRange!Range
    &&  is(immutable  ElementType!Range ==  immutable  dchar)
     &&  isOutputRange!(Output,  dchar))

Lower level control over parsing CSV

std.csv

See Also

Copyright

License

Authors

Types 7

Functions 4