NAME 
input.pir - Setting up input and reading input
DESCRIPTION
Copyright: 2004-2005 Bernhard Schmalhofer. All Rights Reserved. CVS Info: $Id$ History: Ported from GNU m4 1.4 References: http://www.gnu.org/software/m4/m4.html
SUBROUTINES
void input_init( Hash state )
Initialise some stacks and put them into the Hash state['stack']:
- state['stack';'token'] not used yet
- state['stack';'input'] contains files, strings and macro definitions
- state['stack';'wrapup'] not used yet
Initialize some PGE rulesubs and put them into the Hash state['rulesub']:
- state['rulesub';'word'] recognizes TOKEN_WORD.
- state['rulesub';'string'] recognizes TOKEN_STRING
- state['rulesub';'simple'] recognizes TOKEN_SIMPLE
- state['rulesub';'simple'] recognizes comments, returned as TOKEN_SIMPLE
TOOO: recognize nested quoted strings
void push_file( Hash state,
string filename )
Stores a filename on a stack TODO: open these files and complain when they don't or pass filehandles
string next_token( Hash state )
Parse and return a single token from the input stream. A token can either be TOKEN_EOF, if the state['stack';'input'] is empty; it can be TOKEN_STRING for a quoted string; TOKEN_WORD for something that is a potential macro name; and TOKEN_SIMPLE for any single character that is not a part of any of the previous types. | Next_token () return the token type and the token data.
Uses regular expressions for finding tokens.
