Next: Pure Calling, Previous: Token Values, Up: Lexical [Contents][Index]
If you are using the ‘@n’-feature (see Tracking Locations)
in actions to keep track of the textual locations of tokens and groupings,
then you must provide this information in yylex
. The function
yyparse
expects to find the textual location of a token just parsed
in the global variable yylloc
. So yylex
must store the proper
data in that variable.
By default, the value of yylloc
is a structure and you need only
initialize the members that are going to be used by the actions. The
four members are called first_line
, first_column
,
last_line
and last_column
. Note that the use of this
feature makes the parser noticeably slower.
The data type of yylloc
has the name YYLTYPE
.