VocalEasel/mma/MMA/common.py

# common.py

"""
This module is an integeral part of the program
MMA - Musical Midi Accompaniment.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

Bob van der Poel <bvdp@xplornet.com>


These are a collection of miscellaneous routines used in various
parts of MMA. It is safe to load the whole works with:

	from MMA.common import *

without side effects (yeah, right).

"""

from random import randrange
import sys

import gbl


class struct:
	pass

def error(msg):
	""" Print an error message and exit.

	    If the global line number is >=0 then print the line number
	    as well.
	"""

	ln = ""
	if gbl.lineno >= 0:
		ln += "<Line %d>" % gbl.lineno

	if gbl.inpath:
		ln += "<File:%s>" % gbl.inpath.fname

	if ln:
		ln += '\n'

	print "ERROR:%s     %s" % (ln, msg)

	sys.exit(1)


def warning(msg):
	""" Print warning message and return. """


	if gbl.noWarn:
		return

	ln = ""

	if gbl.lineno >= 0:
		ln = "<Line %d>" % gbl.lineno

	if gbl.inpath:
		ln += "<File:%s>" % gbl.inpath.fname

	print "Warning:%s\n        %s" % (ln, msg)



def getOffset(ticks, ran=None):
	""" Calculate a midi offset into a song.

	    ticks == offset into the current bar.
	    ran	  == random adjustment from RTIME

	    When calculating the random factor the test ensures
	    that a note never starts before the start of the bar.
	    This is important ... voice changes, etc. will be
	    buggered if we put the voice change after the first
	    note-on event.
	"""

	p = gbl.tickOffset + int(ticks)	 # int() cast is important!

	if ran:
		r = randrange( -ran, ran+1 )
		if ticks == 0 and r < 0:
			r=0
		p+=r

	return p



def stoi(s, errmsg=None):
	""" string to integer. """

	try:
		return int(s, 0)
	except:
		if errmsg:
			error(errmsg)
		else:
			error("Expecting integer value, not %s" % s)


def stof(s, errmsg=None):
	""" String to floating point. """

	try:
		return float(s)
	except:
		if errmsg:
			error(errmsg)
		else:
			error("Expecting a  value, not %s" % s)




def printList(l):
	""" Print each item in a list. Works for numeric and string."""

	for a in l:
		print a,
	print



def pextract(s, open, close, onlyone=None):
	""" Extract a parenthesized set of substrings.

	s	    - original string
	open    - substring start tag \ can be multiple character
	close   - substring end tag   / strings (ie. "<<" or "-->")
	onlyone - optional, if set only the first set is extracted

	returns ( original sans subs, [subs, ...] )

	eg: pextract( "x{123}{666}y", '{',	'}' )
		Returns:  ( 'xy', [ '123', '666' ] )

	"""

	subs =[]
	while 1:
		lstart = s.find(open)
		lend   = s.find(close)

		if lstart>-1 and lstart < lend:
			subs.append( s[lstart+len(open):lend].strip() )
			s = s[:lstart] + s[lend+len(close):]
			if onlyone:
				break
		else:
			break

	return s.strip(), subs