def __init__(self):
'''
Constructor
'''
self._name = ""
self._body = StatementParse()
self._context = dict()
def parse(self, instream, tokenizer):
'''
Parse the text from the instream into a Program object
'''
# Expect PROGRAM
ttext, ttype = tokenizer.get_next_non_whitespace(instream)
if ttype == Constants._types.KEYWORD and ttext == "PROGRAM":
debug("PROGRAM", False)
else:
exit("Expected PROGRAM to begin the program (But was:" + \
ttext + ")")
# Expect program name
progname, ttype = tokenizer.get_next_non_whitespace(instream)
if ttype == Constants._types.IDENTIFIER:
debug(progname, False)
else:
exit("Expected identifier program name after PROGRAM (But was:" + \
progname + ")")
self.set_name(progname)
# Expect IS
ttext, ttype = tokenizer.get_next_non_whitespace(instream)
if ttype == Constants._types.KEYWORD and ttext == "IS":
debug("IS")
else:
exit("Expected IS after program name (But was:" + ttext + ")")
ttext, ttype = tokenizer.get_next_non_whitespace(instream)
# Loop as long as we continue seeing instructions
while (ttype == Constants._types.KEYWORD and ttext == "INSTRUCTION"):
debug(ttext, False)
# Expect instruction name
name, ttype = tokenizer.get_next_non_whitespace(instream)
if ttype == Constants._types.IDENTIFIER:
debug(name, False)
else:
exit("Expected identifier instruction name after " + \
"INSTRUCTION (But was:" + name + ")")
# Expect IS
ttext, ttype = tokenizer.get_next_non_whitespace(instream)
if ttype == Constants._types.KEYWORD and ttext == "IS":
debug(ttext)
else:
exit("Expected IS after instruction name (But was" + \
ttext + ")")
# Parse the statement block making up the instruction
ttext, ttype = tokenizer.get_next_non_whitespace(instream)
instr = StatementParse()
ttext, ttype = instr.parse_block(instream, tokenizer, ttext, ttype)
self.add_to_context(name, instr)
# Verify we had an END to the instruction
if ttype == Constants._types.KEYWORD and ttext == "END":
debug("END", False)
else:
exit("Expected END to complete the instruction (But was:" + \
ttext + ")")
# Verify matching instruction name after END
ttext, ttype = tokenizer.get_next_non_whitespace(instream)
if ttype == Constants._types.IDENTIFIER and ttext == name:
debug(ttext)
else:
exit("Expected matching instruction name ('" + name + \
"') after END (But was:" + ttext + ")")
ttext, ttype = tokenizer.get_next_non_whitespace(instream)
# Next token should be BEGIN
if ttype == Constants._types.KEYWORD and ttext == "BEGIN":
debug(ttext)
else:
exit("Expected BEGIN to initialize the beginning of the " + \
"program (But was:" + ttext + ")")
# Parse the statement block making up the body
ttext, ttype = tokenizer.get_next_non_whitespace(instream)
instr = StatementParse()
ttext, ttype = instr.parse_block(instream, tokenizer, ttext, ttype)
self.set_body(instr)
# Verify we had an END to the body
if ttype == Constants._types.KEYWORD and ttext == "END":
debug(ttext, False)
else:
exit("Expected END to complete the body (But was:" + ttext + ")")
# Verify matching program name after END
ttext, ttype = tokenizer.get_next_non_whitespace(instream)
if ttype == Constants._types.IDENTIFIER and ttext == progname:
debug(ttext)
else:
exit("Expected matching instruction name ('" + progname + \
"') after END (But was:" + ttext + ")")
'''
Created on Sep 21, 2011
@author: calvin
'''
if __name__ == '__main__':
from StatementParse import StatementParse
from Tokenizer import Tokenizer
t = Tokenizer()
stmt = StatementParse()
f = open("../testinputs/statement.bl")
ttext, ttype = t.get_next_non_whitespace(f)
stmt.parse(f, t, ttext, ttype)
print "\n\n" + str(stmt)
