Format | BOM |
---|---|
UTF-8 | EF BB BF |
UTF-16BE | FE FF |
UTF-16LE | FF FE |
UTF-32BE | 00 00 FE FF |
UTF-32LE | FF FE 00 00 |
UTF-8 | none of the above |
There are no digraphs or trigraphs in D.
The source text is split into tokens using the maximal munch
technique, i.e., the
lexical analyzer tries to make the longest token it can. For example
>>
is a right shift token,
not two greater than tokens.
EndOfFile: physical end of the file \u0000 \u001AThe source text is terminated by whichever comes first.
EndOfLine: \u000D \u000A \u000D \u000A EndOfFileThere is no backslash line splicing, nor are there any limits on the length of a line.
WhiteSpace: Space Space WhiteSpace Space: \u0020 \u0009 \u000B \u000C EndOfLine CommentWhite space is defined as a sequence of one or more of spaces, tabs, vertical tabs, form feeds, end of lines, or comments.
Comment: /* Characters */ // Characters EndOfLine /+ Characters +/D has three kinds of comments:
abc/**/def
is two tokens, abc and def,
not one abcdef token.
Identifier: IdentiferStart IdentiferStart IdentifierChars IdentifierChars: IdentiferChar IdentiferChar IdentifierChars IdentifierStart: _ Letter IdentifierChar: IdentiferStart DigitIdentifiers start with a letter or _, and are followed by any number of letters, _ or digits. Identifiers can be arbitrarilly long, and are case sensitive. Identifiers starting with __ are reserved.
StringLiteral: SingleQuotedString DoubleQuotedString EscapeSequence SingleQuotedString: ' SingleQuotedCharacters ' SingleQuotedCharacter: Character EndOfLine DoubleQuotedString: " DoubleQuotedCharacters " DoubleQuotedCharacter: Character EscapeSequence EndOfLine EscapeSequence: \' \" \? \\ \a \b \f \n \r \t \v \ EndOfFile \x HexDigit HexDigit \ OctalDigit \ OctalDigit OctalDigit \ OctalDigit OctalDigit OctalDigit \u HexDigit HexDigit HexDigit HexDigitA string literal is either a double quoted string, a single quoted string, or an escape sequence.
Single quoted strings are enclosed by ''. All characters between the '' are part of the string except for EndOfLine which is regarded as a single \n character. There are no escape sequences inside '':
'hello' 'c:\root\foo.exe' 'ab\n' string is 4 characters, 'a', 'b', '\', 'n'Double quoted strings are enclosed by "". Escape sequences can be embedded into them with the typical \ notation. EndOfLine is regarded as a single \n character.
"hello" "c:\\root\\foo.exe" "ab\n" string is 3 characters, 'a', 'b', and a linefeed "ab " string is 3 characters, 'a', 'b', and a linefeedEscape strings start with a \ and form an escape character sequence. Adjacent escape strings are concatenated:
\n the linefeed character \t the tab character \" the double quote character \012 octal \x1A hex \u1234 wchar character \r\n carriage return, line feedEscape sequences not listed above are errors.
Adjacent strings are concatenated with the ~ operator, or by simple juxtaposition:
"hello " ~ "world" ~ \n // forms the string 'h','e','l','l','o',' ','w','o','r','l','d',linefeedThe following are all equivalent:
"ab" "c" 'ab' 'c' 'a' "bc" "a" ~ "b" ~ "c" \0x61"bc"
IntegerLiteral: Integer Integer IntegerSuffix Integer: Decimal Binary Octal Hexadecimal IntegerSuffix: l L u U lu Lu lU LU ul uL Ul UL Decimal: 0 NonZeroDigit NonZeroDigit Decimal Binary: 0b BinaryDigits 0B BinaryDigits Octal: 0 OctalDigits Hexadecimal: 0x HexDigits 0X HexDigitsIntegers can be specified in decimal, binary, octal, or hexadecimal.
Decimal integers are a sequence of decimal digits.
Binary integers are a sequence of binary digits preceded by a '0b'.
Octal integers are a sequence of octal digits preceded by a '0'.
Hexadecimal integers are a sequence of hexadecimal digits preceded by a '0x' or followed by an 'h'.
Integers can be immediately followed by one 'l' or one 'u' or both.
The type of the integer is resolved as follows:
FloatLiteral: Float Float FloatSuffix Float ImaginarySuffix Float FloatSuffix ImaginarySuffix Float: DecimalFloat HexFloat FloatSuffix: f F l L ImaginarySuffix: i IFloats can be in decimal or hexadecimal format, as in standard C.
Hexadecimal floats are preceded with a 0x and the exponent is a p or P followed by a power of 2.
Floats can be followed by one f, F, l or L suffix. The f or F suffix means it is a float, and l or L means it is an extended.
If a floating literal is followed by i or I, then it is an ireal (imaginary) type.
Examples:
0x1.FFFFFFFFFFFFFp1023 // double.max 0x1p-52 // double.epsilon 1.175494351e-38F // float.min 6.3i // idouble 6.3 6.3fi // ifloat 6.3 6.3LI // ireal 6.3It is an error if the literal exceeds the range of the type. It is not an error if the literal is rounded to fit into the significant digits of the type.
Complex literals are not tokens, but are assembled from real and imaginary expressions in the semantic analysis:
4.5 + 6.2i // complex number
Keyword: abstract alias align asm assert auto bit body break byte case cast catch cent char class cfloat cdouble creal const continue debug default delegate delete deprecated do double else enum export extern false final finally float for function super null new short int long ifloat idouble ireal if switch synchronized return goto struct interface import static override in out inout private protected public invariant real this throw true try typedef ubyte ucent uint ulong union ushort version void volatile wchar while with
Token: Identifier StringLiteral IntegerLiteral FloatLiteral Keyword / /= . .. ... & &= && | |= || - -= -- + += ++ < <= << <<= <> <>= > >= >>= >>>= >> >>> ! != !== !<> !<>= !< !<= !> !>= ( ) [ ] { } ? , ; : $ = == === * *= % %= ^ ^= ~ ~=
There is currently only one pragma, the #line pragma.
Pragma # line Integer EndOfLine # line Integer Filespec EndOfLine Filespec " Characters "This sets the source line number to Integer, and optionally the source file name to Filespec, beginning with the next line of source text. The source file and line number is used for printing error messages and for mapping generated code back to the source for the symbolic debugging output.
For example:
int #line 6 "foo\bar" x; // this is now line 6 of file foo\barNote that the backslash character is not treated specially inside Filespec strings.