mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-11-20 16:51:10 +00:00
143 lines
4.8 KiB
Python
Executable file
143 lines
4.8 KiB
Python
Executable file
#!/usr/bin/env python
|
|
# -*- Mode: Python; py-indent-offset: 4 -*-
|
|
from __future__ import generators
|
|
|
|
import string
|
|
from cStringIO import StringIO
|
|
|
|
class error(Exception):
|
|
def __init__(self, filename, lineno, msg):
|
|
Exception.__init__(self, msg)
|
|
self.filename = filename
|
|
self.lineno = lineno
|
|
self.msg = msg
|
|
def __str__(self):
|
|
return '%s:%d: error: %s' % (self.filename, self.lineno, self.msg)
|
|
|
|
trans = [' '] * 256
|
|
for i in range(256):
|
|
if chr(i) in string.letters + string.digits + '_':
|
|
trans[i] = chr(i)
|
|
else:
|
|
trans[i] = '_'
|
|
trans = string.join(trans, '')
|
|
|
|
def parse(filename):
|
|
if isinstance(filename, str):
|
|
fp = open(filename, 'r')
|
|
else: # if not string, assume it is some kind of iterator
|
|
fp = filename
|
|
filename = getattr(fp, 'name', '<unknown>')
|
|
whitespace = ' \t\n\r\x0b\x0c'
|
|
nonsymbol = whitespace + '();\'"'
|
|
stack = []
|
|
openlines = []
|
|
lineno = 0
|
|
for line in fp:
|
|
pos = 0
|
|
lineno += 1
|
|
while pos < len(line):
|
|
if line[pos] in whitespace: # ignore whitespace
|
|
pass
|
|
elif line[pos] == ';': # comment
|
|
break
|
|
elif line[pos:pos+2] == "'(":
|
|
pass # the open parenthesis will be handled next iteration
|
|
elif line[pos] == '(':
|
|
stack.append(())
|
|
openlines.append(lineno)
|
|
elif line[pos] == ')':
|
|
if len(stack) == 0:
|
|
raise error(filename, lineno, 'close parenthesis found when none open')
|
|
closed = stack[-1]
|
|
del stack[-1]
|
|
del openlines[-1]
|
|
if stack:
|
|
stack[-1] += (closed,)
|
|
else:
|
|
yield closed
|
|
elif line[pos] == '"': # quoted string
|
|
if not stack:
|
|
raise error(filename, lineno,
|
|
'string found outside of s-expression')
|
|
endpos = pos + 1
|
|
chars = []
|
|
while endpos < len(line):
|
|
if endpos+1 < len(line) and line[endpos] == '\\':
|
|
endpos += 1
|
|
if line[endpos] == 'n':
|
|
chars.append('\n')
|
|
elif line[endpos] == 'r':
|
|
chars.append('\r')
|
|
elif line[endpos] == 't':
|
|
chars.append('\t')
|
|
else:
|
|
chars.append('\\')
|
|
chars.append(line[endpos])
|
|
elif line[endpos] == '"':
|
|
break
|
|
else:
|
|
chars.append(line[endpos])
|
|
endpos += 1
|
|
if endpos >= len(line):
|
|
raise error(filename, lineno, "unclosed quoted string")
|
|
pos = endpos
|
|
stack[-1] += (''.join(chars),)
|
|
else: # symbol/number
|
|
if not stack:
|
|
raise error(filename, lineno,
|
|
'identifier found outside of s-expression')
|
|
endpos = pos
|
|
while endpos < len(line) and line[endpos] not in nonsymbol:
|
|
endpos += 1
|
|
symbol = line[pos:endpos]
|
|
pos = max(pos, endpos-1)
|
|
try: symbol = int(symbol)
|
|
except ValueError:
|
|
try: symbol = float(symbol)
|
|
except ValueError: pass
|
|
stack[-1] += (symbol,)
|
|
pos += 1
|
|
if len(stack) != 0:
|
|
msg = '%d unclosed parentheses found at end of ' \
|
|
'file (opened on line(s) %s)' % (len(stack),
|
|
', '.join(map(str, openlines)))
|
|
raise error(filename, lineno, msg)
|
|
|
|
class Parser:
|
|
def __init__(self, filename):
|
|
"""Argument is either a string, a parse tree, or file object"""
|
|
self.filename = filename
|
|
def startParsing(self, filename=None):
|
|
statements = parse(filename or self.filename)
|
|
for statement in statements:
|
|
self.handle(statement)
|
|
def handle(self, tup):
|
|
cmd = string.translate(tup[0], trans)
|
|
if hasattr(self, cmd):
|
|
getattr(self, cmd)(*tup[1:])
|
|
else:
|
|
self.unknown(tup)
|
|
def unknown(self, tup):
|
|
pass
|
|
|
|
_testString = """; a scheme file
|
|
(define-func gdk_font_load ; a comment at end of line
|
|
GdkFont
|
|
((string name)))
|
|
|
|
(define-boxed GdkEvent
|
|
gdk_event_copy
|
|
gdk_event_free
|
|
"sizeof(GdkEvent)")
|
|
"""
|
|
|
|
if __name__ == '__main__':
|
|
import sys
|
|
if sys.argv[1:]:
|
|
fp = open(sys.argv[1])
|
|
else:
|
|
fp = StringIO(_testString)
|
|
statements = parse(fp)
|
|
for s in statements:
|
|
print `s`
|