FormatSpec

A general handler for format strings.

This handler centers around the function writeUpToNextSpec, which parses the format string until the next format specifier is found. After the call, it provides information about this format specifier in its numerous variables.

struct FormatSpec (

Char

) if (

is(Unqual!Char == Char)

) {

bool startsWith(R doesThisStart) via import std.algorithm.searching : startsWith;;

bool isDigit(dchar c) via import std.ascii : isDigit;;

auto parse(Source s, dchar lbracket, dchar rbracket, dchar keyval, dchar comma) via import std.conv : parse, text, to;;

string text(T args) via import std.conv : parse, text, to;;

template to(T) via import std.conv : parse, text, to;;

int width;

int precision;

int separators;

bool dynamicSeparatorChar;

int separatorCharPos();

void separatorCharPos(int value);

dchar separatorChar;

enum int DYNAMIC;

enum int UNSPECIFIED;

version(StdDdoc)

ubyte allFlags;

const(Char)[] nested;

const(Char)[] sep;

const(Char)[] trailing;

enum immutable(Char)[] seqBefore;

enum immutable(Char)[] seqAfter;

enum immutable(Char)[] keySeparator;

enum immutable(Char)[] seqSeparator;

this(Char[] fmt);

bool writeUpToNextSpec(OutputRange writer);

string toString();

void toString(OutputRange writer);

}

Constructors

this this(Char[] fmt): Creates a new FormatSpec.

Members

Functions

separatorCharPos deprecated int separatorCharPos()
deprecated void separatorCharPos(int value): Set to DYNAMIC when the separator character is supplied at runtime.
toString string toString(): Provides a string representation.
toString void toString(OutputRange writer): Writes a string representation to an output range.
writeUpToNextSpec bool writeUpToNextSpec(OutputRange writer): Writes the format string to an output range until the next format specifier is found and parse that format specifier.

Variables

DYNAMIC enum int DYNAMIC;: Special value for width, precision and separators.
UNSPECIFIED enum int UNSPECIFIED;: Special value for precision and separators.
dynamicSeparatorChar bool dynamicSeparatorChar;: The separator charactar is supplied at runtime.
flDash bool flDash;: The format specifier contained a '-'.
flEqual bool flEqual;: The format specifier contained a '='.
flHash bool flHash;: The format specifier contained a '#'.
flPlus bool flPlus;: The format specifier contained a '+'.
flSeparator bool flSeparator;: The format specifier contained a ','.
flSpace bool flSpace;: The format specifier contained a space.
flZero bool flZero;: The format specifier contained a '0'.
indexEnd ubyte indexEnd;: Index of the last argument for positional parameter ranges.
indexStart ubyte indexStart;: Index of the argument for positional parameters.
keySeparator enum immutable(Char)[] keySeparator;: Sequence ":" inserted between element key and element value of an associative array.
nested const(Char)[] nested;: The inner format string of a nested format specifier.
precision int precision;: Precision. Its semantic depends on the format character.
sep const(Char)[] sep;: The separator of a nested format specifier.
separatorChar dchar separatorChar;: Character to use as separator.
separators int separators;: Number of elements between separators.
seqAfter enum immutable(Char)[] seqAfter;: Sequence "]" inserted after each range or range like structure.
seqBefore enum immutable(Char)[] seqBefore;: Sequence "[" inserted before each range or range like structure.
seqSeparator enum immutable(Char)[] seqSeparator;: Sequence ", " inserted between elements of a range, a range like structure or the elements of an associative array.
spec char spec;: The format character.
trailing const(Char)[] trailing;: Contains the part of the format string, that has not yet been parsed.
width int width;: Minimum width.

Parameters

Char: the character type of the format string

Examples

import std.array : appender;

auto a = appender!(string)();
auto fmt = "Number: %6.4e\nString: %s";
auto f = FormatSpec!char(fmt);

assert(f.writeUpToNextSpec(a));

assert(a.data == "Number: ");
assert(f.trailing == "\nString: %s");
assert(f.spec == 'e');
assert(f.width == 6);
assert(f.precision == 4);

assert(f.writeUpToNextSpec(a));

assert(a.data == "Number: \nString: ");
assert(f.trailing == "");
assert(f.spec == 's');

assert(!f.writeUpToNextSpec(a));

assert(a.data == "Number: \nString: ");