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doc: formatting changes

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* doc/bison.texi: Wrap lines.
No semantical difference.
This commit is contained in:
Akim Demaille
2019-11-07 18:16:14 +01:00
parent 008d927f71
commit b2347a3c3e
1 changed files with 20 additions and 22 deletions
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doc/bison.texi
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@@ -7042,21 +7042,20 @@ Bison}.
@node Calling Convention @node Calling Convention
@subsection Calling Convention for @code{yylex} @subsection Calling Convention for @code{yylex}
The value that @code{yylex} returns must be the positive numeric code The value that @code{yylex} returns must be the positive numeric code for
for the type of token it has just found; a zero or negative value the type of token it has just found; a zero or negative value signifies
signifies end-of-input. end-of-input.
When a token is referred to in the grammar rules by a name, that name When a token is referred to in the grammar rules by a name, that name in the
in the parser implementation file becomes a C macro whose definition parser implementation file becomes a C macro whose definition is the proper
is the proper numeric code for that token type. So @code{yylex} can numeric code for that token type. So @code{yylex} can use the name to
use the name to indicate that type. @xref{Symbols}. indicate that type. @xref{Symbols}.
When a token is referred to in the grammar rules by a character literal, When a token is referred to in the grammar rules by a character literal, the
the numeric code for that character is also the code for the token type. numeric code for that character is also the code for the token type. So
So @code{yylex} can simply return that character code, possibly converted @code{yylex} can simply return that character code, possibly converted to
to @code{unsigned char} to avoid sign-extension. The null character @code{unsigned char} to avoid sign-extension. The null character must not
must not be used this way, because its code is zero and that be used this way, because its code is zero and that signifies end-of-input.
signifies end-of-input.
Here is an example showing these things: Here is an example showing these things:
@@ -7091,17 +7090,16 @@ all others. In this case, the use of the literal string tokens in
the grammar file has no effect on @code{yylex}. the grammar file has no effect on @code{yylex}.
@item @item
@code{yylex} can find the multicharacter token in the @code{yytname} @code{yylex} can find the multicharacter token in the @code{yytname} table.
table. The index of the token in the table is the token type's code. The index of the token in the table is the token type's code. The name of a
The name of a multicharacter token is recorded in @code{yytname} with a multicharacter token is recorded in @code{yytname} with a double-quote, the
double-quote, the token's characters, and another double-quote. The token's characters, and another double-quote. The token's characters are
token's characters are escaped as necessary to be suitable as input escaped as necessary to be suitable as input to Bison.
to Bison.
Here's code for looking up a multicharacter token in @code{yytname}, Here's code for looking up a multicharacter token in @code{yytname},
assuming that the characters of the token are stored in assuming that the characters of the token are stored in @code{token_buffer},
@code{token_buffer}, and assuming that the token does not contain any and assuming that the token does not contain any characters like @samp{"}
characters like @samp{"} that require escaping. that require escaping.
@example @example
for (int i = 0; i < YYNTOKENS; i++) for (int i = 0; i < YYNTOKENS; i++)