class Fail(Token): def __init__(self, lexer, parser, parent): Token.__init__(self, 'Fail', lexer, parser, parent) self.expression = None # "fail" keyword. lexer.expect(self, 'keyword', 'fail') lexer.expect(self, 'whitespace') self.msg = Expression(lexer, parser, parent) # 'If' keyword with an expression. #token = lexer.token() if lexer.next_if('keyword', 'if'): lexer.expect(self, 'whitespace') self.expression = Expression(lexer, parser, parent) # End of expression. self.mark_end() lexer.skip(['whitespace', 'newline']) def value(self, context): if self.expression is None or self.expression.value(context)[0]: raise FailException(self.msg.value(context)[0]) return 1 def dump(self, indent=0): print(' ' * indent) + self.name, 'start' self.msg.dump(indent + 1) self.expression.dump(indent + 1) print(' ' * indent) + self.name, 'end.'
class Fail(Token): def __init__(self, lexer, parser, parent): Token.__init__(self, 'Fail', lexer, parser, parent) self.expression = None # "fail" keyword. lexer.expect(self, 'keyword', 'fail') lexer.expect(self, 'whitespace') self.msg = Expression(lexer, parser, parent) # 'If' keyword with an expression. #token = lexer.token() if lexer.next_if('keyword', 'if'): lexer.expect(self, 'whitespace') self.expression = Expression(lexer, parser, parent) # End of expression. self.mark_end() lexer.skip(['whitespace', 'newline']) def value(self, context): if self.expression is None or self.expression.value(context)[0]: raise FailException(self.msg.value(context)[0]) return 1 def dump(self, indent = 0): print((' ' * indent) + self.name, 'start') self.msg.dump(indent + 1) self.expression.dump(indent + 1) print((' ' * indent) + self.name, 'end.')
class IfCondition(Token): def __init__(self, lexer, parser, parent): Token.__init__(self, 'If-condition', lexer, parser, parent) # Expect an expression. lexer.expect(self, 'keyword', 'if') lexer.expect(self, 'whitespace') self.expression = Expression(lexer, parser, parent) self.mark_end() # Body of the if block. self.if_block = Exscript.interpreter.Code.Code(lexer, parser, parent) self.elif_blocks = [] self.else_block = None # If there is no "else" statement, just return. lexer.skip(['whitespace', 'newline']) if not lexer.next_if('keyword', 'else'): return # If the "else" statement is followed by an "if" (=elif), # read the next if condition recursively and return. lexer.skip(['whitespace', 'newline']) if lexer.current_is('keyword', 'if'): self.else_block = IfCondition(lexer, parser, parent) return # There was no "elif", so we handle a normal "else" condition here. self.else_block = Exscript.interpreter.Code.Code(lexer, parser, parent) def value(self, context): if self.expression.value(context)[0]: self.if_block.value(context) elif self.else_block is not None: self.else_block.value(context) return 1 def dump(self, indent = 0): print((' ' * indent) + self.name, 'start') self.expression.dump(indent + 1) self.if_block.dump(indent + 1) if self.else_block is not None: self.else_block.dump(indent + 1) print((' ' * indent) + self.name, 'end.')
class IfCondition(Token): def __init__(self, lexer, parser, parent): Token.__init__(self, 'If-condition', lexer, parser, parent) # Expect an expression. lexer.expect(self, 'keyword', 'if') lexer.expect(self, 'whitespace') self.expression = Expression(lexer, parser, parent) self.mark_end() # Body of the if block. self.if_block = Code.Code(lexer, parser, parent) self.elif_blocks = [] self.else_block = None # If there is no "else" statement, just return. lexer.skip(['whitespace', 'newline']) if not lexer.next_if('keyword', 'else'): return # If the "else" statement is followed by an "if" (=elif), # read the next if condition recursively and return. lexer.skip(['whitespace', 'newline']) if lexer.current_is('keyword', 'if'): self.else_block = IfCondition(lexer, parser, parent) return # There was no "elif", so we handle a normal "else" condition here. self.else_block = Code.Code(lexer, parser, parent) def value(self, context): if self.expression.value(context)[0]: self.if_block.value(context) elif self.else_block is not None: self.else_block.value(context) return 1 def dump(self, indent=0): print(' ' * indent) + self.name, 'start' self.expression.dump(indent + 1) self.if_block.dump(indent + 1) if self.else_block is not None: self.else_block.dump(indent + 1) print(' ' * indent) + self.name, 'end.'
class Loop(Token): def __init__(self, lexer, parser, parent): Token.__init__(self, 'Loop', lexer, parser, parent) self.during = None self.until = None self.thefrom = None self.theto = None self.list_variables = [] self.iter_varnames = [] # Expect one ore more lists. lexer.expect(self, 'keyword', 'loop') lexer.expect(self, 'whitespace') if not lexer.current_is('keyword', 'while') and \ not lexer.current_is('keyword', 'until') and \ not lexer.current_is('keyword', 'from'): self.list_variables = [Term(lexer, parser, parent)] lexer.next_if('whitespace') while lexer.next_if('comma'): lexer.skip(['whitespace', 'newline']) self.list_variables.append(Term(lexer, parser, parent)) lexer.skip(['whitespace', 'newline']) # Expect the "as" keyword. lexer.expect(self, 'keyword', 'as') # The iterator variable. lexer.next_if('whitespace') _, iter_varname = lexer.token() lexer.expect(self, 'varname') parent.define(**{iter_varname: []}) self.iter_varnames = [iter_varname] lexer.next_if('whitespace') while lexer.next_if('comma'): lexer.skip(['whitespace', 'newline']) _, iter_varname = lexer.token() lexer.expect(self, 'varname') parent.define(**{iter_varname: []}) self.iter_varnames.append(iter_varname) lexer.skip(['whitespace', 'newline']) if len(self.iter_varnames) != len(self.list_variables): error = '%s lists, but only %s iterators in loop' % (len(self.iter_varnames), len(self.list_variables)) lexer.syntax_error(error, self) # Check if this is a "from ... to ..." loop. if lexer.next_if('keyword', 'from'): lexer.expect(self, 'whitespace') self.thefrom = Expression(lexer, parser, parent) lexer.next_if('whitespace') lexer.expect(self, 'keyword', 'to') self.theto = Expression(lexer, parser, parent) lexer.next_if('whitespace') if lexer.next_if('keyword', 'as'): lexer.next_if('whitespace') _, iter_varname = lexer.token() lexer.expect(self, 'varname') lexer.next_if('whitespace') else: iter_varname = 'counter' parent.define(**{iter_varname: []}) self.iter_varnames = [iter_varname] # Check if this is a "while" loop. if lexer.next_if('keyword', 'while'): lexer.expect(self, 'whitespace') self.during = Expression(lexer, parser, parent) lexer.next_if('whitespace') # Check if this is an "until" loop. if lexer.next_if('keyword', 'until'): lexer.expect(self, 'whitespace') self.until = Expression(lexer, parser, parent) lexer.next_if('whitespace') # End of statement. self.mark_end() # Body of the loop block. lexer.skip(['whitespace', 'newline']) self.block = Code.Code(lexer, parser, parent) def value(self, context): if len(self.list_variables) == 0 and not self.thefrom: # If this is a "while" loop, iterate as long as the condition is True. if self.during is not None: while self.during.value(context)[0]: self.block.value(context) return 1 # If this is an "until" loop, iterate until the condition is True. if self.until is not None: while not self.until.value(context)[0]: self.block.value(context) return 1 # Retrieve the lists from the list terms. if self.thefrom: start = self.thefrom.value(context)[0] stop = self.theto.value(context)[0] lists = [range(start, stop)] else: lists = [var.value(context) for var in self.list_variables] vars = self.iter_varnames # Make sure that all lists have the same length. for list in lists: if len(list) != len(lists[0]): msg = 'All list variables must have the same length' self.lexer.runtime_error(msg, self) # Iterate. for i in xrange(len(lists[0])): f = 0 for list in lists: self.block.define(**{vars[f]: [list[i]]}) f += 1 if self.until is not None and self.until.value(context)[0]: break if self.during is not None and not self.during.value(context)[0]: break self.block.value(context) return 1 def dump(self, indent = 0): print (' ' * indent) + self.name, print self.list_variables, 'as', self.iter_varnames, 'start' if self.during is not None: self.during.dump(indent + 1) if self.until is not None: self.until.dump(indent + 1) self.block.dump(indent + 1) print (' ' * indent) + self.name, 'end.'