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* NEWS: Reword %destructor vs YYABORT etc.
* data/glr.c: Use American spacing, for consistency. * data/glr.cc: Likewise. * data/lalr1.cc: Likewise. * data/yacc.c: Likewise. * data/yacc.c: Reformat comments slightly. * doc/bison.texinfo: Replace "non-" with "non" when that makes sense, for consistency. Fix some spelling errors and reword recently-included text slightly. * tests/cxx-type.at: Cast results of malloc, for C++.
This commit is contained in:
13
ChangeLog
13
ChangeLog
@@ -1,3 +1,16 @@
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|||||||
|
2005-12-21 Paul Eggert <eggert@cs.ucla.edu>
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|
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* NEWS: Reword %destructor vs YYABORT etc.
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|
* data/glr.c: Use American spacing, for consistency.
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|
* data/glr.cc: Likewise.
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|
* data/lalr1.cc: Likewise.
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* data/yacc.c: Likewise.
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|
* data/yacc.c: Reformat comments slightly.
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|
* doc/bison.texinfo: Replace "non-" with "non" when that makes sense,
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|
for consistency. Fix some spelling errors and reword recently-included
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|
text slightly.
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|
* tests/cxx-type.at: Cast results of malloc, for C++.
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|
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2005-12-21 Joel E. Denny <address@hidden>
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2005-12-21 Joel E. Denny <address@hidden>
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|
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* tests/cxx-type.at: Construct a tree, count the parents of shared
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* tests/cxx-type.at: Construct a tree, count the parents of shared
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8
NEWS
8
NEWS
@@ -3,10 +3,10 @@ Bison News
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|
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||||||
Changes in version 2.1a:
|
Changes in version 2.1a:
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|
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* %destructor vs. YYACCEPT, YYERROR, and YYABORT.
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* %destructor vs. YYABORT, YYACCEPT, and YYERROR.
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||||||
When the parsing/action is cut by the user using one of these
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Destructors are now called when user code invokes YYABORT, YYACCEPT,
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special actions, the stack is freed except the right-hand side
|
and YYERROR, for all objects on the stack, other than objects
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||||||
symbols of the current rule.
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corresponding to the right-hand side of the current rule.
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||||||
|
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||||||
* GLR, C++ LALR(1) parsers.
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* GLR, C++ LALR(1) parsers.
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These parser skeletons are now distributed with the same special
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These parser skeletons are now distributed with the same special
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@@ -666,7 +666,7 @@ do { \
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[[short int *top], [top]])[
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[[short int *top], [top]])[
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{
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{
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YYFPRINTF (stderr, "Stack now");
|
YYFPRINTF (stderr, "Stack now");
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for (/* Nothing. */; bottom <= top; ++bottom)
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for (; bottom <= top; ++bottom)
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YYFPRINTF (stderr, " %d", *bottom);
|
YYFPRINTF (stderr, " %d", *bottom);
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YYFPRINTF (stderr, "\n");
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YYFPRINTF (stderr, "\n");
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}
|
}
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@@ -1052,7 +1052,7 @@ b4_c_function_def([yyparse], [int], b4_parse_param)
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]b4_location_if([ YYLTYPE yyloc;])[
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]b4_location_if([ YYLTYPE yyloc;])[
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|
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/* The number of symbols on the RHS of the reduced rule.
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/* The number of symbols on the RHS of the reduced rule.
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Keep to zero when no symbol should be popped off. */
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Keep to zero when no symbol should be popped. */
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int yylen = 0;
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int yylen = 0;
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|
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YYDPRINTF ((stderr, "Starting parse\n"));
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YYDPRINTF ((stderr, "Starting parse\n"));
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@@ -1097,8 +1097,7 @@ m4_ifdef([b4_at_dollar_used], [[ yylsp[0] = yylloc;
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`------------------------------------------------------------*/
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`------------------------------------------------------------*/
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yynewstate:
|
yynewstate:
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/* In all cases, when you get here, the value and location stacks
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/* In all cases, when you get here, the value and location stacks
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have just been pushed. so pushing a state here evens the stacks.
|
have just been pushed. So pushing a state here evens the stacks. */
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*/
|
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yyssp++;
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yyssp++;
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|
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yysetstate:
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yysetstate:
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@@ -461,7 +461,7 @@ more information on this.
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@cindex @acronym{GLR} parsing
|
@cindex @acronym{GLR} parsing
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@cindex generalized @acronym{LR} (@acronym{GLR}) parsing
|
@cindex generalized @acronym{LR} (@acronym{GLR}) parsing
|
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@cindex ambiguous grammars
|
@cindex ambiguous grammars
|
||||||
@cindex non-deterministic parsing
|
@cindex nondeterministic parsing
|
||||||
|
|
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Parsers for @acronym{LALR}(1) grammars are @dfn{deterministic}, meaning
|
Parsers for @acronym{LALR}(1) grammars are @dfn{deterministic}, meaning
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||||||
roughly that the next grammar rule to apply at any point in the input is
|
roughly that the next grammar rule to apply at any point in the input is
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||||||
@@ -469,7 +469,7 @@ uniquely determined by the preceding input and a fixed, finite portion
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(called a @dfn{look-ahead}) of the remaining input. A context-free
|
(called a @dfn{look-ahead}) of the remaining input. A context-free
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grammar can be @dfn{ambiguous}, meaning that there are multiple ways to
|
grammar can be @dfn{ambiguous}, meaning that there are multiple ways to
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apply the grammar rules to get the same inputs. Even unambiguous
|
apply the grammar rules to get the same inputs. Even unambiguous
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||||||
grammars can be @dfn{non-deterministic}, meaning that no fixed
|
grammars can be @dfn{nondeterministic}, meaning that no fixed
|
||||||
look-ahead always suffices to determine the next grammar rule to apply.
|
look-ahead always suffices to determine the next grammar rule to apply.
|
||||||
With the proper declarations, Bison is also able to parse these more
|
With the proper declarations, Bison is also able to parse these more
|
||||||
general context-free grammars, using a technique known as @acronym{GLR}
|
general context-free grammars, using a technique known as @acronym{GLR}
|
||||||
@@ -2126,7 +2126,7 @@ as @code{sin}, @code{cos}, etc.
|
|||||||
|
|
||||||
It is easy to add new operators to the infix calculator as long as they are
|
It is easy to add new operators to the infix calculator as long as they are
|
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only single-character literals. The lexical analyzer @code{yylex} passes
|
only single-character literals. The lexical analyzer @code{yylex} passes
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back all nonnumber characters as tokens, so new grammar rules suffice for
|
back all nonnumeric characters as tokens, so new grammar rules suffice for
|
||||||
adding a new operator. But we want something more flexible: built-in
|
adding a new operator. But we want something more flexible: built-in
|
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functions whose syntax has this form:
|
functions whose syntax has this form:
|
||||||
|
|
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@@ -2411,7 +2411,7 @@ getsym (char const *sym_name)
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|
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The function @code{yylex} must now recognize variables, numeric values, and
|
The function @code{yylex} must now recognize variables, numeric values, and
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the single-character arithmetic operators. Strings of alphanumeric
|
the single-character arithmetic operators. Strings of alphanumeric
|
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characters with a leading non-digit are recognized as either variables or
|
characters with a leading letter are recognized as either variables or
|
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functions depending on what the symbol table says about them.
|
functions depending on what the symbol table says about them.
|
||||||
|
|
||||||
The string is passed to @code{getsym} for look up in the symbol table. If
|
The string is passed to @code{getsym} for look up in the symbol table. If
|
||||||
@@ -2782,7 +2782,7 @@ into a separate header file @file{@var{name}.tab.h} which you can include
|
|||||||
in the other source files that need it. @xref{Invocation, ,Invoking Bison}.
|
in the other source files that need it. @xref{Invocation, ,Invoking Bison}.
|
||||||
|
|
||||||
If you want to write a grammar that is portable to any Standard C
|
If you want to write a grammar that is portable to any Standard C
|
||||||
host, you must use only non-null character tokens taken from the basic
|
host, you must use only nonnull character tokens taken from the basic
|
||||||
execution character set of Standard C@. This set consists of the ten
|
execution character set of Standard C@. This set consists of the ten
|
||||||
digits, the 52 lower- and upper-case English letters, and the
|
digits, the 52 lower- and upper-case English letters, and the
|
||||||
characters in the following C-language string:
|
characters in the following C-language string:
|
||||||
@@ -3813,7 +3813,7 @@ For instance, if your locations use a file name, you may use
|
|||||||
During error recovery (@pxref{Error Recovery}), symbols already pushed
|
During error recovery (@pxref{Error Recovery}), symbols already pushed
|
||||||
on the stack and tokens coming from the rest of the file are discarded
|
on the stack and tokens coming from the rest of the file are discarded
|
||||||
until the parser falls on its feet. If the parser runs out of memory,
|
until the parser falls on its feet. If the parser runs out of memory,
|
||||||
or if the parsing is cut by @code{YYACCEPT} or @code{YYABORT}, all the
|
or if it returns via @code{YYABORT} or @code{YYACCEPT}, all the
|
||||||
symbols on the stack must be discarded. Even if the parser succeeds, it
|
symbols on the stack must be discarded. Even if the parser succeeds, it
|
||||||
must discard the start symbol.
|
must discard the start symbol.
|
||||||
|
|
||||||
@@ -3862,16 +3862,18 @@ stacked symbols popped during the first phase of error recovery,
|
|||||||
incoming terminals during the second phase of error recovery,
|
incoming terminals during the second phase of error recovery,
|
||||||
@item
|
@item
|
||||||
the current look-ahead and the entire stack (except the current
|
the current look-ahead and the entire stack (except the current
|
||||||
right-hand side symbols) when the parser aborts (either via an explicit
|
right-hand side symbols) when the parser returns immediately, and
|
||||||
call to @code{YYABORT} or @code{YYACCEPT}, or as a consequence of a
|
|
||||||
failed error recovery or of memory exhaustion), and
|
|
||||||
@item
|
@item
|
||||||
the start symbol, when the parser succeeds.
|
the start symbol, when the parser succeeds.
|
||||||
@end itemize
|
@end itemize
|
||||||
|
|
||||||
Note that right-hand size symbols of a rule that explicitly triggers a
|
The parser can @dfn{return immediately} because of an explicit call to
|
||||||
syntax error via @code{YYERROR} are not reclaimed. As a thumb rule,
|
@code{YYABORT} or @code{YYACCEPT}, or failed error recovery, or memory
|
||||||
destructors are invoked only when you do not have other means to manage
|
exhaustion.
|
||||||
|
|
||||||
|
Right-hand size symbols of a rule that explicitly triggers a syntax
|
||||||
|
error via @code{YYERROR} are not discarded automatically. As a rule
|
||||||
|
of thumb, destructors are invoked only when user actions cannot manage
|
||||||
the memory.
|
the memory.
|
||||||
|
|
||||||
@node Expect Decl
|
@node Expect Decl
|
||||||
@@ -3959,8 +3961,8 @@ may override this restriction with the @code{%start} declaration as follows:
|
|||||||
A @dfn{reentrant} program is one which does not alter in the course of
|
A @dfn{reentrant} program is one which does not alter in the course of
|
||||||
execution; in other words, it consists entirely of @dfn{pure} (read-only)
|
execution; in other words, it consists entirely of @dfn{pure} (read-only)
|
||||||
code. Reentrancy is important whenever asynchronous execution is possible;
|
code. Reentrancy is important whenever asynchronous execution is possible;
|
||||||
for example, a non-reentrant program may not be safe to call from a signal
|
for example, a nonreentrant program may not be safe to call from a signal
|
||||||
handler. In systems with multiple threads of control, a non-reentrant
|
handler. In systems with multiple threads of control, a nonreentrant
|
||||||
program must be called only within interlocks.
|
program must be called only within interlocks.
|
||||||
|
|
||||||
Normally, Bison generates a parser which is not reentrant. This is
|
Normally, Bison generates a parser which is not reentrant. This is
|
||||||
@@ -4450,7 +4452,7 @@ The @code{yytname} table is generated only if you use the
|
|||||||
@subsection Semantic Values of Tokens
|
@subsection Semantic Values of Tokens
|
||||||
|
|
||||||
@vindex yylval
|
@vindex yylval
|
||||||
In an ordinary (non-reentrant) parser, the semantic value of the token must
|
In an ordinary (nonreentrant) parser, the semantic value of the token must
|
||||||
be stored into the global variable @code{yylval}. When you are using
|
be stored into the global variable @code{yylval}. When you are using
|
||||||
just one data type for semantic values, @code{yylval} has that type.
|
just one data type for semantic values, @code{yylval} has that type.
|
||||||
Thus, if the type is @code{int} (the default), you might write this in
|
Thus, if the type is @code{int} (the default), you might write this in
|
||||||
@@ -5610,7 +5612,7 @@ pp.@: 615--649 @uref{http://doi.acm.org/10.1145/69622.357187}.
|
|||||||
@cindex @acronym{GLR} parsing
|
@cindex @acronym{GLR} parsing
|
||||||
@cindex generalized @acronym{LR} (@acronym{GLR}) parsing
|
@cindex generalized @acronym{LR} (@acronym{GLR}) parsing
|
||||||
@cindex ambiguous grammars
|
@cindex ambiguous grammars
|
||||||
@cindex non-deterministic parsing
|
@cindex nondeterministic parsing
|
||||||
|
|
||||||
Bison produces @emph{deterministic} parsers that choose uniquely
|
Bison produces @emph{deterministic} parsers that choose uniquely
|
||||||
when to reduce and which reduction to apply
|
when to reduce and which reduction to apply
|
||||||
@@ -5675,10 +5677,10 @@ quadratic worst-case time, and any general (possibly ambiguous)
|
|||||||
context-free grammar in cubic worst-case time. However, Bison currently
|
context-free grammar in cubic worst-case time. However, Bison currently
|
||||||
uses a simpler data structure that requires time proportional to the
|
uses a simpler data structure that requires time proportional to the
|
||||||
length of the input times the maximum number of stacks required for any
|
length of the input times the maximum number of stacks required for any
|
||||||
prefix of the input. Thus, really ambiguous or non-deterministic
|
prefix of the input. Thus, really ambiguous or nondeterministic
|
||||||
grammars can require exponential time and space to process. Such badly
|
grammars can require exponential time and space to process. Such badly
|
||||||
behaving examples, however, are not generally of practical interest.
|
behaving examples, however, are not generally of practical interest.
|
||||||
Usually, non-determinism in a grammar is local---the parser is ``in
|
Usually, nondeterminism in a grammar is local---the parser is ``in
|
||||||
doubt'' only for a few tokens at a time. Therefore, the current data
|
doubt'' only for a few tokens at a time. Therefore, the current data
|
||||||
structure should generally be adequate. On @acronym{LALR}(1) portions of a
|
structure should generally be adequate. On @acronym{LALR}(1) portions of a
|
||||||
grammar, in particular, it is only slightly slower than with the default
|
grammar, in particular, it is only slightly slower than with the default
|
||||||
@@ -7037,7 +7039,7 @@ The output files @file{@var{output}.hh} and @file{@var{output}.cc}
|
|||||||
declare and define the parser class in the namespace @code{yy}. The
|
declare and define the parser class in the namespace @code{yy}. The
|
||||||
class name defaults to @code{parser}, but may be changed using
|
class name defaults to @code{parser}, but may be changed using
|
||||||
@samp{%define "parser_class_name" "@var{name}"}. The interface of
|
@samp{%define "parser_class_name" "@var{name}"}. The interface of
|
||||||
this class is detailled below. It can be extended using the
|
this class is detailed below. It can be extended using the
|
||||||
@code{%parse-param} feature: its semantics is slightly changed since
|
@code{%parse-param} feature: its semantics is slightly changed since
|
||||||
it describes an additional member of the parser class, and an
|
it describes an additional member of the parser class, and an
|
||||||
additional argument for its constructor.
|
additional argument for its constructor.
|
||||||
@@ -7065,7 +7067,7 @@ Get or set the stream used for tracing the parsing. It defaults to
|
|||||||
@deftypemethod {parser} {debug_level_type} debug_level ()
|
@deftypemethod {parser} {debug_level_type} debug_level ()
|
||||||
@deftypemethodx {parser} {void} set_debug_level (debug_level @var{l})
|
@deftypemethodx {parser} {void} set_debug_level (debug_level @var{l})
|
||||||
Get or set the tracing level. Currently its value is either 0, no trace,
|
Get or set the tracing level. Currently its value is either 0, no trace,
|
||||||
or non-zero, full tracing.
|
or nonzero, full tracing.
|
||||||
@end deftypemethod
|
@end deftypemethod
|
||||||
|
|
||||||
@deftypemethod {parser} {void} error (const location_type& @var{l}, const std::string& @var{m})
|
@deftypemethod {parser} {void} error (const location_type& @var{l}, const std::string& @var{m})
|
||||||
@@ -7116,7 +7118,7 @@ actually easier to interface with.
|
|||||||
@subsection Calc++ --- C++ Calculator
|
@subsection Calc++ --- C++ Calculator
|
||||||
|
|
||||||
Of course the grammar is dedicated to arithmetics, a single
|
Of course the grammar is dedicated to arithmetics, a single
|
||||||
expression, possibily preceded by variable assignments. An
|
expression, possibly preceded by variable assignments. An
|
||||||
environment containing possibly predefined variables such as
|
environment containing possibly predefined variables such as
|
||||||
@code{one} and @code{two}, is exchanged with the parser. An example
|
@code{one} and @code{two}, is exchanged with the parser. An example
|
||||||
of valid input follows.
|
of valid input follows.
|
||||||
@@ -7480,7 +7482,7 @@ blank [ \t]
|
|||||||
@end example
|
@end example
|
||||||
|
|
||||||
@noindent
|
@noindent
|
||||||
The following paragraph suffices to track locations acurately. Each
|
The following paragraph suffices to track locations accurately. Each
|
||||||
time @code{yylex} is invoked, the begin position is moved onto the end
|
time @code{yylex} is invoked, the begin position is moved onto the end
|
||||||
position. Then when a pattern is matched, the end position is
|
position. Then when a pattern is matched, the end position is
|
||||||
advanced of its width. In case it matched ends of lines, the end
|
advanced of its width. In case it matched ends of lines, the end
|
||||||
@@ -7505,7 +7507,7 @@ preceding tokens. Comments would be treated equally.
|
|||||||
The rules are simple, just note the use of the driver to report errors.
|
The rules are simple, just note the use of the driver to report errors.
|
||||||
It is convenient to use a typedef to shorten
|
It is convenient to use a typedef to shorten
|
||||||
@code{yy::calcxx_parser::token::identifier} into
|
@code{yy::calcxx_parser::token::identifier} into
|
||||||
@code{token::identifier} for isntance.
|
@code{token::identifier} for instance.
|
||||||
|
|
||||||
@comment file: calc++-scanner.ll
|
@comment file: calc++-scanner.ll
|
||||||
@example
|
@example
|
||||||
@@ -7949,7 +7951,7 @@ parser file. @xref{Decl Summary}.
|
|||||||
@end deffn
|
@end deffn
|
||||||
|
|
||||||
@deffn {Directive} %nonassoc
|
@deffn {Directive} %nonassoc
|
||||||
Bison declaration to assign non-associativity to token(s).
|
Bison declaration to assign nonassociativity to token(s).
|
||||||
@xref{Precedence Decl, ,Operator Precedence}.
|
@xref{Precedence Decl, ,Operator Precedence}.
|
||||||
@end deffn
|
@end deffn
|
||||||
|
|
||||||
|
|||||||
@@ -231,7 +231,7 @@ yyerror (ERROR_PARAMETERS)
|
|||||||
static Node *
|
static Node *
|
||||||
new_nterm (char const *form, Node *child0, Node *child1, Node *child2)
|
new_nterm (char const *form, Node *child0, Node *child1, Node *child2)
|
||||||
{
|
{
|
||||||
Node *node = malloc (sizeof (Node));
|
Node *node = (Node *) malloc (sizeof (Node));
|
||||||
node->nterm.type = 1;
|
node->nterm.type = 1;
|
||||||
node->nterm.parents = 0;
|
node->nterm.parents = 0;
|
||||||
node->nterm.form = form;
|
node->nterm.form = form;
|
||||||
@@ -250,7 +250,7 @@ new_nterm (char const *form, Node *child0, Node *child1, Node *child2)
|
|||||||
static Node *
|
static Node *
|
||||||
new_term (char *text)
|
new_term (char *text)
|
||||||
{
|
{
|
||||||
Node *node = malloc (sizeof (Node));
|
Node *node = (Node *) malloc (sizeof (Node));
|
||||||
node->term.type = 0;
|
node->term.type = 0;
|
||||||
node->term.parents = 0;
|
node->term.parents = 0;
|
||||||
node->term.text = text;
|
node->term.text = text;
|
||||||
@@ -286,7 +286,7 @@ node_to_string (Node *node)
|
|||||||
char *buffer;
|
char *buffer;
|
||||||
if (!node)
|
if (!node)
|
||||||
{
|
{
|
||||||
buffer = malloc (1);
|
buffer = (char *) malloc (1);
|
||||||
buffer[0] = 0;
|
buffer[0] = 0;
|
||||||
}
|
}
|
||||||
else if (node->node_info.type == 1)
|
else if (node->node_info.type == 1)
|
||||||
@@ -294,7 +294,7 @@ node_to_string (Node *node)
|
|||||||
child0 = node_to_string (node->nterm.children[0]);
|
child0 = node_to_string (node->nterm.children[0]);
|
||||||
child1 = node_to_string (node->nterm.children[1]);
|
child1 = node_to_string (node->nterm.children[1]);
|
||||||
child2 = node_to_string (node->nterm.children[2]);
|
child2 = node_to_string (node->nterm.children[2]);
|
||||||
buffer = malloc (strlen (node->nterm.form) + strlen (child0)
|
buffer = (char *) malloc (strlen (node->nterm.form) + strlen (child0)
|
||||||
+ strlen (child1) + strlen (child2) + 1);
|
+ strlen (child1) + strlen (child2) + 1);
|
||||||
sprintf (buffer, node->nterm.form, child0, child1, child2);
|
sprintf (buffer, node->nterm.form, child0, child1, child2);
|
||||||
free (child0);
|
free (child0);
|
||||||
|
|||||||
Reference in New Issue
Block a user