init_data
variable is a global
variable accessible to everyone that uses the scanner. Each time the scanner is
asked for the next token (using scan
), an (in principle undividable) token is delivered.
Sometimes, however, a token comes with extra information. E.g. if a token appears
to be the 'number token', the parser needs to know exactly which number is associated
to that number token. This information is exported by the scanner through the
init_scan
variable.