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_ dans les constantes numeriques; \xHH dans les chaines et les caracteres 

git-svn-id: http://caml.inria.fr/svn/ocamldoc/trunk@10006 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
master
Damien Doligez 2002-10-03 11:42:45 +00:00
parent 3298afa5d5
commit 75f205d5fe
1 changed files with 21 additions and 9 deletions
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30
manual/manual/refman/lex.etex
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@ -29,19 +29,20 @@ character), and "'" (the single quote), starting with a
letter or an underscore.
Letters contain at least the 52 lowercase and uppercase
letters from the ASCII set. The current implementation (except on
MacOS) also recognizes as letters all accented characters from the ISO
MacOS 9) also recognizes as letters all accented characters from the ISO
8859-1 (``ISO Latin 1'') set. All characters in an identifier are
meaningful. The current implementation places no limits on the number
of characters of an identifier.
meaningful. The current implementation places practically no limit on
the number of characters of an identifier.
\subsubsection*{Integer literals}
\begin{syntax}
integer-literal:
["-"] {{ "0"\ldots"9" }}
| ["-"] ("0x"||"0X") {{ "0"\ldots"9"||"A"\ldots"F"||"a"\ldots"f" }}
| ["-"] ("0o"||"0O") {{ "0"\ldots"7" }}
| ["-"] ("0b"||"0B") {{ "0"\ldots"1" }}
["-"] ("0"\ldots"9") { "0"\ldots"9"||"_" }
| ["-"] ("0x"||"0X") ("0"\ldots"9"||"A"\ldots"F"||"a"\ldots"f")
{ "0"\ldots"9"||"A"\ldots"F"||"a"\ldots"f"||"_" }
| ["-"] ("0o"||"0O") ("0"\ldots"7") { "0"\ldots"7"||"_" }
| ["-"] ("0b"||"0B") ("0"\ldots"1") { "0"\ldots"1"||"_" }
\end{syntax}
An integer literal is a sequence of one or more digits, optionally
@ -56,12 +57,15 @@ preceded by a minus sign. By default, integer literals are in decimal
The interpretation of integer literals that fall outside the range of
representable integer values is undefined.
For convenience and readability, underscore characters ("_") are accepted
(and ignored) within integer literals.
\subsubsection*{Floating-point literals}
\begin{syntax}
float-literal:
["-"] {{ "0"\ldots"9" }} ["." { "0"\ldots"9" }]
[("e"||"E") ["+"||"-"] {{ "0"\ldots"9" }}]
["-"] ("0"\ldots"9") { "0"\ldots"9"||"_" } ["." { "0"\ldots"9"||"_" }]
[("e"||"E") ["+"||"-"] ("0"\ldots"9") { "0"\ldots"9"||"_" }]
\end{syntax}
Floating-point decimals consist in an integer part, a decimal part and
@ -75,6 +79,9 @@ avoid ambiguity with integer literals.
The interpretation of floating-point literals that fall outside the
range of representable floating-point values is undefined.
For convenience and readability, underscore characters ("_") are accepted
(and ignored) within floating-point literals.
\subsubsection*{Character literals}
\label{s:characterliteral}
@ -86,6 +93,8 @@ char-literal:
escape-sequence:
"\" ("\" || '"' || "'" || "n" || "t" || "b" || "r")
| "\" ("0"\ldots"9") ("0"\ldots"9") ("0"\ldots"9")
| "\x" ("0"\ldots"9"||"A"\ldots"F"||"a"\ldots"f")
("0"\ldots"9"||"A"\ldots"F"||"a"\ldots"f")
\end{syntax}
Character literals are delimited by "'" (single quote) characters.
@ -100,6 +109,7 @@ The two single quotes enclose either one character different from
\entree{"\\t"}{horizontal tabulation (TAB)}
\entree{"\\b"}{backspace (BS)}
\entree{"\\"\var{ddd}}{the character with ASCII code \var{ddd} in decimal}
\entree{"\\x"\var{hh}}{the caracter with ASCII code \var{hh} in hexadecimal}
\end{tableau}
\subsubsection*{String literals}
@ -220,3 +230,5 @@ a positive integer (the source line number), optionally followed by a
character string (the source file name).
Line number directives are treated as blank characters during lexical
analysis.
% $Id$