class Program:
def __init__(self, atomsFile, programFile):
self.atoms = {}
self.prog = ''
self.PIF = []
self.symTable = Tree()
self.outCodes = {}
self.lineCount = 1
self.symTableAddress = 1
self.fa_const = Automata('fa_const.txt')
self.fa_id = Automata('fa_id.txt')
# print self.fa_const.verifySequence('-0.123121231111')
with open(atomsFile, 'r') as f:
for line in f:
atom, code = line.split(' ')
self.atoms[atom] = int(code)
self.logName = 'parser_log_' + strftime('%Y%m%d_%H%M%S',
gmtime()) + '.txt'
if os.path.exists(self.logName):
os.remove(self.logName)
self.startParser(programFile)
def Log(self, msg):
pass
def updatePifAndSymTable(self, prefix):
if prefix in self.atoms:
self.PIF.append(Atom(self.atoms[prefix], '-', prefix))
else:
n = CustomNode(prefix, self.symTableAddress)
nFind = self.symTable.findNode(n)
if nFind is None:
# print 'This is not a keytoken:', prefix
self.symTableAddress += 1
self.symTable.addNode(n)
nFind = n
if self.fa_id.verifySequence(prefix)[0]:
self.PIF.append(Atom(self.atoms['ID'], nFind.code, prefix))
else:
self.PIF.append(Atom(self.atoms['CONST'], nFind.code, prefix))
def startParser(self, programFile):
isPartOfId = False
with open(programFile, 'r') as f:
for line in f:
line = line.strip()
lastPos = 0
i = 0
while i < len(line):
# print i
crtSeq = line[lastPos:i + 1]
# print 'checking sequence', repr(crtSeq)
status, prefix = self.fa_id.verifySequence(crtSeq)
if not status and prefix == '':
status2, prefix2 = self.fa_const.verifySequence(crtSeq)
if status2 or prefix2 != '':
status, prefix = status2, prefix2
# print 'Crt seq:', repr(crtSeq), status, repr(prefix)
if not status:
if i < len(line) - 1 and line[i:i + 2] in {
'<=', '>=', '==', '<>'
}:
if prefix != '':
self.updatePifAndSymTable(prefix)
isPartOfId = False
self.updatePifAndSymTable(line[i:i + 2])
i += 2
elif line[i] in {
' ', ';', ',', '(', ')', '<', '>', '_', '.'
}:
if line[i] != '.':
if prefix != '':
self.updatePifAndSymTable(prefix)
isPartOfId = False
if isPartOfId is True and line[i] != ' ':
print 'Syntax error at line [%d] - [%s]!' % (
self.lineCount, line[i])
sys.exit(0)
if line[i] not in {' ', '_'}:
self.updatePifAndSymTable(line[i])
if line[i] == '_':
isPartOfId = True
else:
isPartOfId = True
i += 1
elif line[i] == ':':
if prefix != '':
self.updatePifAndSymTable(prefix)
isPartOfId = False
if i < len(line) - 1 and line[i + 1] == '=':
self.updatePifAndSymTable(':=')
i += 2
else:
self.updatePifAndSymTable(':')
i += 1
elif line[i] in {'+', '-', '/', '*'}:
if prefix != '':
self.updatePifAndSymTable(prefix)
isPartOfId = False
if line[i] in {'+', '-'}:
if not self.fa_id.verifySequence(
line[i + 1]
)[0] and not self.fa_const.verifySequence(
line[i + 1]):
self.updatePifAndSymTable(line[i])
else:
isPartOfId = True
i += 1
elif line[i] in {'$', '%', '&'}:
isPartOfId = True
i += 1
else:
print 'Syntax error at line %d! Unexpected token [%s].' % (
self.lineCount, line[i])
sys.exit(0)
if not isPartOfId:
lastPos = i
else:
i += 1
if i == len(line) and (status or prefix != ''):
self.updatePifAndSymTable(prefix)
self.lineCount += 1
def printPIF(self):
print '%-10s|\t%-10s|\t%-40s' % ('CODE', 'ADDRESS', 'VALUE')
print '%-10s|\t%-10s|\t%-40s' % ('_________', '__________',
'___________')
for at in self.PIF:
print at
def printSymTable(self):
self.symTable.printTree()
class Program:
def __init__(self, atomsFile, programFile):
self.atoms = {}
self.prog = ''
self.PIF = []
self.symTable = Tree()
self.outCodes = {}
self.lineCount = 1
self.symTableAddress = 1
self.fa_const = Automata('fa_const.txt')
self.fa_id = Automata('fa_id.txt')
with open(atomsFile, 'r') as f:
for line in f:
atom, code = line.split(' ')
self.atoms[atom] = int(code)
self.logName = 'parser_log_' + strftime('%Y%m%d_%H%M%S', gmtime()) + '.txt'
if os.path.exists(self.logName):
os.remove(self.logName)
self.startParser(programFile)
def Log(self, msg):
pass
# with open(self.logName, 'a') as f:
# f.write(msg+'\n')
def initSymTable(self, tokens):
for t in tokens:
t = t.strip()
if ' ' in t:
print 'Error at line %d. Missing comma between variables [%s]' % (self.lineCount, t)
sys.exit(0)
if len(t) > 255:
print 'Error at line %d. Identifier length exceeds 255 (%d)' % (self.lineCount, len(t))
sys.exit(0)
if not self.fa_id.verifySequence(t)[0]:
print 'Syntax error at line %d [%s]' % (self.lineCount, t)
sys.exit(0)
n = CustomNode(t, self.symTableAddress)
self.symTableAddress += 1
self.symTable.addNode(n)
self.PIF.append(Atom(self.atoms['ID'], n.code, t))
def startParser(self, programFile):
begins = 0
ends = 0
ifs = 0
elses = 0
firstLine = True
lastLine = False
with open(programFile, 'r') as f:
for line in f:
if lastLine:
print 'Error at line %d! Found more code after END. keyword!' % self.lineCount
sys.exit(0)
line = line.strip()
if line == '':
self.lineCount += 1
continue
if firstLine:
firstLine = False
if not line.upper().startswith('VAR'):
print 'Error at line %d. Could not find declaration of variables!' % self.lineCount
sys.exit(0)
line = line[3:].lstrip()
self.PIF.append(Atom(self.atoms['VAR'], '-', 'VAR'))
self.Log('Found starting VAR')
if ',' in line:
self.Log('Found declarations line: %s' % line)
self.parseDeclarations(line)
elif line.startswith('READ') or line.startswith('WRITE'):
self.Log('Found READ/WRITE line: %s' % line)
self.parseReadWrite(line)
elif line == 'BEGIN':
begins += 1
self.PIF.append(Atom(self.atoms['BEGIN'], '-', 'BEGIN'))
elif 'END' in line and ';' in line:
ends += 1
if ends > begins:
print 'Error at line %d. No BEGIN to match the current END!' % self.lineCount
sys.exit(0)
self.PIF.append(Atom(self.atoms['END'], '-', 'END'))
self.PIF.append(Atom(self.atoms[';'], '-', ';'))
elif line == 'END.':
self.PIF.append(Atom(self.atoms['END'], '-', 'END.'))
lastLine = True
elif ':=' in line:
self.Log('Found assignment line: %s' % line)
self.parseAssign(line)
elif line.startswith('IF') and line.endswith('THEN'):
self.Log('Found if stmt line: %s' % line)
self.parseIf(line)
ifs += 1
elif line == 'ELSE':
elses += 1
if elses > ifs:
print 'Error at line %d. No IF to match the current ELSE!' % self.lineCount
sys.exit(0)
self.PIF.append(Atom(self.atoms['ELSE'], '-', 'ELSE'))
elif line.startswith('WHILE') and line.endswith('DO'):
self.parseWhile(line)
else:
print 'Error at line %d. Unmatched syntax [%s].' % (self.lineCount, line)
sys.exit(0)
self.lineCount += 1
if not lastLine:
print 'Error! Could not find END. keyword!'
sys.exit(0)
def parseDeclarations(self, line):
varsAndType = line.split(':')
if len(varsAndType) != 2:
print 'Error at line %d [%s].' % (self.lineCount, line)
sys.exit(0)
variables, declType = varsAndType
tokens = variables.split(',')
if ';' not in declType:
print 'Error at line %d. Missing ending ;.' % self.lineCount
sys.exit(0)
declType = declType.replace(';','').strip()
self.initSymTable(tokens)
self.PIF.append(Atom(self.atoms[declType], '-', declType))
self.PIF.append(Atom(self.atoms[';'], '-', ';'))
def parseReadWrite(self, line):
if 'READ' in line:
readOrWrite = 'READ'
else:
readOrWrite = 'WRITE'
line = line.replace(readOrWrite, '').strip()
if not line.startswith('('):
print 'Error at line %d. Missing open bracket (.' % self.lineCount
sys.exit(0)
self.PIF.append(Atom(self.atoms[readOrWrite.upper()], '-', readOrWrite))
self.PIF.append(Atom(self.atoms['('], '-', '('))
line = line.replace('(', '').strip()
tokens = line.split(')')
if len(tokens) != 2 or (len(tokens) == 2 and tokens[1].strip() != ';'):
print 'Syntax error at line %d [%s]' % (self.lineCount, line)
sys.exit(0)
identifier = tokens[0].strip()
identMatch = self.fa_id.verifySequence(identifier)[0]
numMatch = self.fa_const.verifySequence(identifier)[0]
if numMatch:
if readOrWrite == 'READ':
print 'Error at line %d. Cannot read constants!' % self.lineCount
sys.exit(0)
n = CustomNode(identifier, self.symTableAddress)
nFind = self.symTable.findNode(n)
if nFind is None:
self.symTableAddress += 1
self.symTable.addNode(n)
self.PIF.append(Atom(self.atoms['CONST'], n.code, identifier))
elif identMatch:
n = CustomNode(identifier, self.symTableAddress)
nFind = self.symTable.findNode(n)
if nFind is None:
self.symTableAddress += 1
self.symTable.addNode(n)
self.PIF.append(Atom(self.atoms['ID'], n.code, identifier))
else:
print 'Syntax error at line %d [%s]' % (self.lineCount, identifier)
sys.exit(0)
self.PIF.append(Atom(self.atoms[')'], '-', ')'))
self.PIF.append(Atom(self.atoms[';'], '-', ';'))
def parseExpression(self, line, hasEnding=True):
operators = []
tokens = []
crtToken = ''
i = 0
while i < len(line):
if line[i] not in '+-/*' and line[i:i+3] != 'MOD':
crtToken += line[i]
i += 1
elif line[i] in '+-/*':
tokens.append(crtToken)
crtToken = ''
operators.append(line[i])
i += 1
elif line[i:i+3] == 'MOD':
# print 'found mod on line ', line, 'at index', i
tokens.append(crtToken)
crtToken = ''
operators.append('MOD')
i += 3
if crtToken != '':
tokens.append(crtToken)
tokens = [t.strip() for t in tokens]
if hasEnding:
if ';' not in tokens[-1]:
print 'Missing ";" on line %d: [%s]' % (self.lineCount, line)
sys.exit(0)
tokens[-1] = tokens[-1].replace(';', '').strip()
self.Log('Separated expression tokens: ' + str(tokens))
self.Log('Operators between tokens: ' + str(operators))
# print tokens, operators
crtOperator = 0
for t in tokens:
identMatch = self.fa_id.verifySequence(t)[0]
numMatch = self.fa_const.verifySequence(t)[0]
if identMatch:
if len(t) > 255:
print 'Error at line %d. Identifier length exceeds 255 (%d)' % (self.lineCount, len(t))
sys.exit(0)
n = CustomNode(t, self.symTableAddress)
nFind = self.symTable.findNode(n)
if nFind is None:
self.symTableAddress += 1
self.symTable.addNode(n)
self.PIF.append(Atom(self.atoms['ID'], n.code, t))
elif numMatch:
n = CustomNode(t, self.symTableAddress)
nFind = self.symTable.findNode(n)
if nFind is None:
self.symTable.addNode(n)
self.symTableAddress += 1
self.PIF.append(Atom(self.atoms['CONST'], n.code, t))
else:
self.errSyntax(t)
if len(operators) > 0 and crtOperator < len(operators):
# self.Log(str(len(operators)) + ' - ' + str(crtOperator))
self.PIF.append(Atom(self.atoms[operators[crtOperator]], '-', operators[crtOperator]))
crtOperator += 1
if hasEnding:
self.PIF.append(Atom(self.atoms[';'], '-', ';'))
def parseAssign(self, line):
leftRight = [t.strip() for t in line.split(':=')]
self.Log('Separated assignment parts: ' + str(leftRight))
left, right = leftRight[0], leftRight[1]
if not self.fa_id.verifySequence(left)[0]:
self.errSyntax(left)
if len(left) > 255:
print 'Error at line %d. Identifier length exceeds 255 (%d)' % (self.lineCount, len(left))
sys.exit(0)
n = CustomNode(left, self.symTableAddress)
nFind = self.symTable.findNode(n)
if nFind is None:
self.symTable.addNode(n)
self.symTableAddress += 1
self.PIF.append(Atom(self.atoms['ID'], n.code, left))
self.PIF.append(Atom(self.atoms[':='], '-', ':='))
self.parseExpression(right)
def parseIf(self, line):
self.PIF.append(Atom(self.atoms['IF'], '-', 'IF'))
line = line.replace('IF', '').strip()
line = line.replace('THEN', '').strip()
crtComparator = None
for comp in {'>', '<', '>=', '<=', '<>', '=='}:
if comp in line:
crtComparator = comp
break
if crtComparator is None:
print 'Error at line %d. Bad expression after IF: %s!' % (self.lineCount, line)
sys.exit(0)
leftRight = line.split(crtComparator)
self.Log('Separated expression parts: ' + str(leftRight))
left, right = leftRight[0], leftRight[1]
self.parseExpression(left, False)
self.PIF.append(Atom(self.atoms[crtComparator], '-', crtComparator))
self.parseExpression(right, False)
self.PIF.append(Atom(self.atoms['THEN'], '-', 'THEN'))
def parseWhile(self, line):
self.PIF.append(Atom(self.atoms['WHILE'], '-', 'WHILE'))
line = line.replace('WHILE', '').replace('DO', '').strip()
crtComparator = None
for comp in {'>', '<', '>=', '<=', '<>', '=='}:
if comp in line:
crtComparator = comp
break
if crtComparator is None:
print 'Error at line %d. Bad expression after IF: %s!' % (self.lineCount, line)
sys.exit(0)
leftRight = line.split(crtComparator)
self.Log('Separated expression parts: ' + str(leftRight))
left, right = leftRight[0], leftRight[1]
self.parseExpression(left, False)
self.PIF.append(Atom(self.atoms[crtComparator], '-', crtComparator))
self.parseExpression(right, False)
self.PIF.append(Atom(self.atoms['DO'], '-', 'DO'))
def errUndeclaredVar(self, varName):
print 'Error at line %d. Usage of undeclared variable [%s]' % (self.lineCount, varName)
sys.exit(0)
def errSyntax(self, unkToken):
print 'Syntax error at line %d. Unknown token [%s]' % (self.lineCount, unkToken)
sys.exit(0)
def printAtomRules(self):
print self.atoms
def printProgram(self):
print self.prog
def printPIF(self):
print '%-10s|\t%-10s|\t%-40s' % ('CODE', 'ADDRESS', 'VALUE')
print '%-10s|\t%-10s|\t%-40s' % ('_________', '__________', '___________')
for at in self.PIF:
print at
def printSymTable(self):
self.symTable.printTree()