VocalEasel/mma/MMA/file.py
Matthias Neeracher f54adbeec5 Update to MMA 1.7
2011-07-26 22:49:39 +00:00

320 lines
8.5 KiB
Python

# file.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 <bob@mellowood.ca>
"""
import sys
import os
import gbl
from MMA.common import *
def fixfname(f):
""" Convert embedded space characters in filename to real spaces.
Originally this was done with .decode("string-escape") but that
doesn't work with windows path names. So, now we just replace
any \x20 sequences with single spaces.
"""
f = f.replace('\\x20', ' ')
return os.path.expanduser(f)
def locFile(name, lib):
""" Locate a filename.
This checks, in order:
lib/name + .mma
lib/name
name + .mma
name
"""
ext=gbl.ext
exists = os.path.exists
name=fixfname(name) # for ~ expansion only
if lib:
if not name.endswith(ext):
t=os.path.join(lib, name + ext)
if exists(t):
return t
t=os.path.join(lib, name)
if exists(t):
return t
if not name.endswith(ext):
t = name + ext
if exists(t):
return t
if exists(name):
return name
return None
###########################
# File read class
###########################
class ReadFile:
class FileData:
""" After reading the file in bulk it is parsed and stored in this
data structure. Blanks lines and comments are removed.
"""
def __init__(self, lnum, data, label):
self.lnum=lnum
self.data=data
self.label=label
def __init__(self, fname):
self.fdata=fdata=[]
self.lastline = None
self.lineptr = None
self.fname = None
self.que = [] # que for pushed lines (mainly for REPEAT)
self.qnums = []
dataStore = self.FileData # shortcut to avoid '.'s
try:
inpath = file(fname, 'r')
except:
error("Unable to open '%s' for input" % fname)
if gbl.debug or gbl.showFilenames:
print "Opening file '%s'." % fname
self.fname = fname
""" Read entire file, line by line:
- strip off blanks, comments
- join continuation lines
- parse out LABELS
- create line numbers
"""
lcount=0
label=''
labs=[] # track label defs, error if duplicate in same file
nlabs=[] # track linenumber label defs
while 1:
l = inpath.readline()
if not l: # EOF
break
l= l.strip()
lcount += 1
if not l:
continue
# join lines ending in '\' (the strip() makes this the last char
while l[-1] == '\\':
l = l[0:-1] + ' ' + inpath.readline().strip()
lcount +=1
""" input cleanup ... for now the only cleanup is to convert
0xa0 (non-breakable space) to 0x20 (regular space).
"""
l=l.replace('\xa0', '\x20')
""" This next line splits the line at the first found
comment '//', drops the comment, and splits the
remaining line into tokens using whitespace delimiters.
Note that split() will strip off trailing and leading
spaces, so a strip() is not needed here.
"""
l = l.split('//',1)[0].split()
if not l:
continue
""" Parse out label lines. There are 2 different kinds of labels:
- LABEL XXX
and
- NNN
The first kind is treated as an exclusive. If a NNN label or previous
XXX duplicates, and error is generated.
The LINE NUMBER type is not exclusive. If a duplicate NNN is found, the
last one is used.
XXX NNN types can not duplicate each other.
Also note that XXX lines are stripped from input as well as NNN lines
with only a NNN.
"""
if l[0].upper()=='LABEL':
if len(l) !=2:
gbl.lineno = lcount
error("Usage: LABEL <string>")
label=l[1].upper()
if label[0]=='$':
gbl.lineno = lcount
error("Variables are not permitted as labels")
if label in labs:
gbl.lineno = lcount
error("Duplicate label specified in line %s" % lcount)
elif label in nlabs:
gbl.lineno = lcount
error("Label '%s' duplicates line number label" % label)
labs.append(label)
elif l[0].isdigit():
label=l[0]
if label in labs:
gbl.lineno = lcount
error("Line number '%s' duplicates LABEL" % label)
if not label in nlabs:
nlabs.append(label)
else:
for i, a in enumerate(fdata):
if a.label == label:
fdata[i].label=''
else:
label = None
# Save the line, linenumber and (maybe) the label.
fdata.append( dataStore(lcount, l, label))
inpath.close()
self.lineptr = 0
self.lastline = len(fdata)
def toEof(self):
""" Move pointer to End of File. """
self.lineptr=self.lastline+1
self.que = []
self.qnums = []
def goto(self, l):
""" Do a goto jump.
This isn't perfect, but is probably the way most GOTOs work. If
inside a repeat/if then nothing more is processed. The jump is
immediate. Of course, you'll run into problems with missing
repeat/repeatend if you try it. Since all repeats are stacked
back into the que, we just delete the que. Then we look for a
matching label in the file line array.
Label search is linear. Not too efficient, but the lists
will probably never be that long either.
"""
if not l:
error("No label specified")
if self.que:
self.que=[]
for i,a in enumerate(self.fdata):
if a.label == l:
self.lineptr=i
return
error("Label '%s' has not be set" % l)
def push(self, q, nums):
""" Push a list of lines back into the input stream.
Note: This is a list of semi-processed lines, no comments, etc.
It's quicker to extend a list than to insert, so add to the end.
Note: we reverse the original, extend() then reverse again, just
in case the caller cares.
nums is a list of linenumbers. Needed to report error lines.
"""
if not self.que:
self.que = ['']
self.qnums=[gbl.lineno]
q.reverse()
self.que.extend(q)
q.reverse()
nums.reverse()
self.qnums.extend(nums)
nums.reverse()
def read(self):
""" Return a line.
This will return either a queued line or a line from the
file (which was stored/processed earlier).
"""
while 1:
if self.que: # Return a queued line if possible.
ln = self.que.pop(-1)
gbl.lineno = self.qnums.pop()
if not ln:
continue
return ln
# Return the next line in the file.
if self.lineptr>=self.lastline:
return None #### EOF
ln=self.fdata[self.lineptr].data
gbl.lineno = self.fdata[self.lineptr].lnum
self.lineptr +=1
return ln