Code inside the parser may refer to the variable yylex,
which holds the yyLexer passed to Parse.
-The "-p prefix" flag to goyacc sets the prefix, by default yy, that
-begins the names of symbols, including types, the parser, and the
-lexer, generated and referenced by goyacc's generated code. Setting
-it to distinct values allows multiple grammars to be used in a
-single binary.
+Multiple grammars compiled into a single program should be placed in
+distinct packages. If that is impossible, the "-p prefix" flag to
+goyacc sets the prefix, by default yy, that begins the names of
+symbols, including types, the parser, and the lexer, generated and
+referenced by goyacc's generated code. Setting it to distinct values
+allows multiple grammars to be placed in a single package.
*/
package documentation