def __init__(self, reader, universe): self._universe = universe self._lexer = Lexer(reader) self._bc_gen = BytecodeGenerator() self._sym = Symbol.NONE self._text = None self._next_sym = Symbol.NONE self._get_symbol_from_lexer()
class Parser(object): _single_op_syms = (Symbol.Not, Symbol.And, Symbol.Or, Symbol.Star, Symbol.Div, Symbol.Mod, Symbol.Plus, Symbol.Equal, Symbol.More, Symbol.Less, Symbol.Comma, Symbol.At, Symbol.Per, Symbol.NONE) _binary_op_syms = (Symbol.Or, Symbol.Comma, Symbol.Minus, Symbol.Equal, Symbol.Not, Symbol.And, Symbol.Or, Symbol.Star, Symbol.Div, Symbol.Mod, Symbol.Plus, Symbol.Equal, Symbol.More, Symbol.Less, Symbol.Comma, Symbol.At, Symbol.Per, Symbol.NONE) _keyword_selector_syms = (Symbol.Keyword, Symbol.KeywordSequence) def __init__(self, reader, universe): self._universe = universe self._lexer = Lexer(reader) self._bc_gen = BytecodeGenerator() self._sym = Symbol.NONE self._text = None self._next_sym = Symbol.NONE self._get_symbol_from_lexer() def classdef(self, cgenc): cgenc.set_name(self._universe.symbol_for(self._text)) self._expect(Symbol.Identifier) self._expect(Symbol.Equal) if self._sym == Symbol.Identifier: super_name = self._universe.symbol_for(self._text) self._accept(Symbol.Identifier) else: super_name = self._universe.symbol_for("Object") cgenc.set_super_name(super_name) # Load the super class if super_name.get_string( ) == "nil": # Break the dependency cycle by hard coding the values for Object cgenc.set_number_of_instance_fields_of_super( 0) # Object's super class is nil, has no fields cgenc.set_number_of_class_fields_of_super( 4) # Object's class has the fields of Class else: super_class = self._universe.load_class(super_name) cgenc.set_number_of_instance_fields_of_super( super_class.get_number_of_instance_fields()) cgenc.set_number_of_class_fields_of_super( super_class.get_class().get_number_of_instance_fields()) self._expect(Symbol.NewTerm) self._instance_fields(cgenc) while (self._sym == Symbol.Identifier or self._sym == Symbol.Keyword or self._sym == Symbol.OperatorSequence or self._sym_in(self._binary_op_syms)): mgenc = MethodGenerationContext() mgenc.set_holder(cgenc) mgenc.add_argument("self") self._method(mgenc) if mgenc.is_primitive(): cgenc.add_instance_method( mgenc.assemble_primitive(self._universe)) else: cgenc.add_instance_method(mgenc.assemble(self._universe)) if self._accept(Symbol.Separator): cgenc.set_class_side(True) self._class_fields(cgenc) while (self._sym == Symbol.Identifier or self._sym == Symbol.Keyword or self._sym == Symbol.OperatorSequence or self._sym_in(self._binary_op_syms)): mgenc = MethodGenerationContext() mgenc.set_holder(cgenc) mgenc.add_argument("self") self._method(mgenc) if mgenc.is_primitive(): cgenc.add_class_method( mgenc.assemble_primitive(self._universe)) else: cgenc.add_class_method(mgenc.assemble(self._universe)) self._expect(Symbol.EndTerm) def _sym_in(self, symbol_list): return self._sym in symbol_list def _accept(self, s): if self._sym == s: self._get_symbol_from_lexer() return True return False def _accept_one_of(self, symbol_list): if self._sym_in(symbol_list): self._get_symbol_from_lexer() return True return False def _expect(self, s): if self._accept(s): return True err = ( "Error: unexpected symbol in line %d. Expected %s, but found %s" % (self._lexer.get_current_line_number(), Symbol.as_str(s), Symbol.as_str(self._sym))) if self._printable_symbol(): err += " (" + self._text + ")" err += ": " + self._lexer.get_raw_buffer() raise ValueError(err) def _expect_one_of(self, symbol_list): if self._accept_one_of(symbol_list): return True expected = ", ".join([Symbol.as_str(x) for x in symbol_list]) err = ( "Error: unexpected symbol in line %d. Expected one of %s, but found %s" % (self._lexer.get_current_line_number(), expected, Symbol.as_str(self._sym))) if self._printable_symbol(): err += " (" + self._text + ")" err += ": " + self._lexer.get_raw_buffer() raise ValueError(err) def _instance_fields(self, cgenc): if self._accept(Symbol.Or): while self._sym == Symbol.Identifier: var = self._variable() cgenc.add_instance_field(self._universe.symbol_for(var)) self._expect(Symbol.Or) def _class_fields(self, cgenc): if self._accept(Symbol.Or): while self._sym == Symbol.Identifier: var = self._variable() cgenc.add_class_field(self._universe.symbol_for(var)) self._expect(Symbol.Or) def _method(self, mgenc): self._pattern(mgenc) self._expect(Symbol.Equal) if self._sym == Symbol.Primitive: mgenc.set_primitive(True) self._primitive_block() else: self._method_block(mgenc) def _primitive_block(self): self._expect(Symbol.Primitive) def _pattern(self, mgenc): if self._sym == Symbol.Identifier: self._unary_pattern(mgenc) elif self._sym == Symbol.Keyword: self._keyword_pattern(mgenc) else: self._binary_pattern(mgenc) def _unary_pattern(self, mgenc): mgenc.set_signature(self._unary_selector()) def _binary_pattern(self, mgenc): mgenc.set_signature(self._binary_selector()) mgenc.add_argument_if_absent(self._argument()) def _keyword_pattern(self, mgenc): kw = self._keyword() mgenc.add_argument_if_absent(self._argument()) while self._sym == Symbol.Keyword: kw += self._keyword() mgenc.add_argument_if_absent(self._argument()) mgenc.set_signature(self._universe.symbol_for(kw)) def _method_block(self, mgenc): self._expect(Symbol.NewTerm) self._block_contents(mgenc) # if no return has been generated so far, we can be sure there was no . # terminating the last expression, so the last expression's value must # be popped off the stack and a ^self be generated if not mgenc.is_finished(): self._bc_gen.emitPOP(mgenc) self._bc_gen.emitPUSHARGUMENT(mgenc, 0, 0) self._bc_gen.emitRETURNLOCAL(mgenc) mgenc.set_finished() self._expect(Symbol.EndTerm) def _unary_selector(self): return self._universe.symbol_for(self._identifier()) def _binary_selector(self): s = self._text if self._accept(Symbol.Or): pass elif self._accept(Symbol.Comma): pass elif self._accept(Symbol.Minus): pass elif self._accept(Symbol.Equal): pass elif self._accept_one_of(self._single_op_syms): pass elif self._accept(Symbol.OperatorSequence): pass else: self._expect(Symbol.NONE) return self._universe.symbol_for(s) def _identifier(self): s = self._text is_primitive = self._accept(Symbol.Primitive) if not is_primitive: self._expect(Symbol.Identifier) return s def _keyword(self): s = self._text self._expect(Symbol.Keyword) return s def _argument(self): return self._variable() def _block_contents(self, mgenc): if self._accept(Symbol.Or): self._locals(mgenc) self._expect(Symbol.Or) self._block_body(mgenc, False) def _locals(self, mgenc): while (self._sym == Symbol.Identifier): mgenc.add_local_if_absent(self._variable()) def _block_body(self, mgenc, seenPeriod): if self._accept(Symbol.Exit): self._result(mgenc) elif self._sym == Symbol.EndBlock: if seenPeriod: # a POP has been generated which must be elided (blocks always # return the value of the last expression, regardless of # whether it was terminated with a . or not) mgenc.remove_last_bytecode() self._bc_gen.emitRETURNLOCAL(mgenc) mgenc.set_finished() elif self._sym == Symbol.EndTerm: # it does not matter whether a period has been seen, as the end of # the method has been found (EndTerm) - so it is safe to emit a # "return self" self._bc_gen.emitPUSHARGUMENT(mgenc, 0, 0) self._bc_gen.emitRETURNLOCAL(mgenc) mgenc.set_finished() else: self._expression(mgenc) if self._accept(Symbol.Period): self._bc_gen.emitPOP(mgenc) self._block_body(mgenc, True) def _result(self, mgenc): self._expression(mgenc) if mgenc.is_block_method(): self._bc_gen.emitRETURNNONLOCAL(mgenc) else: self._bc_gen.emitRETURNLOCAL(mgenc) mgenc.set_finished(True) self._accept(Symbol.Period) def _expression(self, mgenc): self._peek_for_next_symbol_from_lexer() if self._next_sym == Symbol.Assign: self._assignation(mgenc) else: self._evaluation(mgenc) def _assignation(self, mgenc): l = [] self._assignments(mgenc, l) self._evaluation(mgenc) for assignment in l: self._bc_gen.emitDUP(mgenc) for assignment in l: self._gen_pop_variable(mgenc, assignment) def _assignments(self, mgenc, l): if self._sym == Symbol.Identifier: l.append(self._assignment(mgenc)) self._peek_for_next_symbol_from_lexer() if self._next_sym == Symbol.Assign: self._assignments(mgenc, l) def _assignment(self, mgenc): v = self._variable() var = self._universe.symbol_for(v) mgenc.add_literal_if_absent(var) self._expect(Symbol.Assign) return v def _evaluation(self, mgenc): # single: superSend is_super_send = [False] self._primary(mgenc, is_super_send) if (self._sym == Symbol.Identifier or self._sym == Symbol.Keyword or self._sym == Symbol.OperatorSequence or self._sym_in(self._binary_op_syms)): self._messages(mgenc, is_super_send) def _primary(self, mgenc, is_super_send): is_super_send[0] = False if self._sym == Symbol.Identifier: v = self._variable() if v == "super": is_super_send[0] = True # sends to super push self as the receiver v = "self" self._gen_push_variable(mgenc, v) elif self._sym == Symbol.NewTerm: self._nested_term(mgenc) elif self._sym == Symbol.NewBlock: bgenc = MethodGenerationContext() bgenc.set_is_block_method(True) bgenc.set_holder(mgenc.get_holder()) bgenc.set_outer(mgenc) self._nested_block(bgenc) block_method = bgenc.assemble(self._universe) mgenc.add_literal(block_method) self._bc_gen.emitPUSHBLOCK(mgenc, block_method) else: self._literal(mgenc) def _variable(self): return self._identifier() def _messages(self, mgenc, is_super_send): if self._sym == Symbol.Identifier: while self._sym == Symbol.Identifier: # only the first message in a sequence can be a super send self._unary_message(mgenc, is_super_send) is_super_send[0] = False while (self._sym == Symbol.OperatorSequence or self._sym_in(self._binary_op_syms)): self._binary_message(mgenc, [False]) if self._sym == Symbol.Keyword: self._keyword_message(mgenc, [False]) elif (self._sym == Symbol.OperatorSequence or self._sym_in(self._binary_op_syms)): while (self._sym == Symbol.OperatorSequence or self._sym_in(self._binary_op_syms)): # only the first message in a sequence can be a super send self._binary_message(mgenc, is_super_send) is_super_send[0] = False if self._sym == Symbol.Keyword: self._keyword_message(mgenc, [False]) else: self._keyword_message(mgenc, is_super_send) def _unary_message(self, mgenc, is_super_send): msg = self._unary_selector() mgenc.add_literal_if_absent(msg) if is_super_send[0]: self._bc_gen.emitSUPERSEND(mgenc, msg) else: self._bc_gen.emitSEND(mgenc, msg) def _binary_message(self, mgenc, is_super_send): msg = self._binary_selector() mgenc.add_literal_if_absent(msg) self._binary_operand(mgenc, [False]) if is_super_send[0]: self._bc_gen.emitSUPERSEND(mgenc, msg) else: self._bc_gen.emitSEND(mgenc, msg) def _binary_operand(self, mgenc, is_super_send): self._primary(mgenc, is_super_send) while self._sym == Symbol.Identifier: self._unary_message(mgenc, is_super_send) def _keyword_message(self, mgenc, is_super_send): kw = self._keyword() self._formula(mgenc) while self._sym == Symbol.Keyword: kw += self._keyword() self._formula(mgenc) msg = self._universe.symbol_for(kw) mgenc.add_literal_if_absent(msg) if is_super_send[0]: self._bc_gen.emitSUPERSEND(mgenc, msg) else: self._bc_gen.emitSEND(mgenc, msg) def _formula(self, mgenc): is_super_send = [False] self._binary_operand(mgenc, is_super_send) # only the first message in a sequence can be a super send if self._sym == Symbol.OperatorSequence or self._sym_in( self._binary_op_syms): self._binary_message(mgenc, is_super_send) while self._sym == Symbol.OperatorSequence or self._sym_in( self._binary_op_syms): self._binary_message(mgenc, [False]) def _nested_term(self, mgenc): self._expect(Symbol.NewTerm) self._expression(mgenc) self._expect(Symbol.EndTerm) def _literal(self, mgenc): if self._sym == Symbol.Pound: self._literal_symbol(mgenc) elif self._sym == Symbol.STString: self._literal_string(mgenc) else: self._literal_number(mgenc) def _literal_number(self, mgenc): if self._sym == Symbol.Minus: val = self._negative_decimal() else: val = self._literal_decimal() if Integer.value_fits(val): lit = self._universe.new_integer(val) else: lit = self._universe.new_biginteger(val) mgenc.add_literal_if_absent(lit) self._bc_gen.emitPUSHCONSTANT(mgenc, lit) def _literal_decimal(self): return self._literal_integer() def _negative_decimal(self): self._expect(Symbol.Minus) return -self._literal_integer() def _literal_integer(self): i = int(self._text) self._expect(Symbol.Integer) return i def _literal_symbol(self, mgenc): self._expect(Symbol.Pound) if self._sym == Symbol.STString: s = self._string() symb = self._universe.symbol_for(s) else: symb = self._selector() mgenc.add_literal_if_absent(symb) self._bc_gen.emitPUSHCONSTANT(mgenc, symb) def _literal_string(self, mgenc): s = self._string() string = self._universe.new_string(s) mgenc.add_literal_if_absent(string) self._bc_gen.emitPUSHCONSTANT(mgenc, string) def _selector(self): if self._sym == Symbol.OperatorSequence or self._sym_in( self._single_op_syms): return self._binary_selector() elif self._sym == Symbol.Keyword or self._sym == Symbol.KeywordSequence: return self._keyword_selector() else: return self._unary_selector() def _keyword_selector(self): s = self._text self._expect_one_of(self._keyword_selector_syms) symb = self._universe.symbol_for(s) return symb def _string(self): s = self._text self._expect(Symbol.STString) return s def _nested_block(self, mgenc): mgenc.add_argument_if_absent("$block self") self._expect(Symbol.NewBlock) if self._sym == Symbol.Colon: self._block_pattern(mgenc) # generate Block signature block_sig = "$block method" arg_size = mgenc.get_number_of_arguments() block_sig += ":" * (arg_size - 1) mgenc.set_signature(self._universe.symbol_for(block_sig)) self._block_contents(mgenc) # if no return has been generated, we can be sure that the last # expression in the block was not terminated by ., and can generate # a return if not mgenc.is_finished(): self._bc_gen.emitRETURNLOCAL(mgenc) mgenc.set_finished(True) self._expect(Symbol.EndBlock) def _block_pattern(self, mgenc): self._block_arguments(mgenc) self._expect(Symbol.Or) def _block_arguments(self, mgenc): self._expect(Symbol.Colon) mgenc.add_argument_if_absent(self._argument()) while self._sym == Symbol.Colon: self._expect(Symbol.Colon) mgenc.add_argument_if_absent(self._argument()) def _gen_push_variable(self, mgenc, var): # The purpose of this function is to find out whether the variable to be # pushed on the stack is a local variable, argument, or object field. # This is done by examining all available lexical contexts, starting with # the innermost (i.e., the one represented by mgenc). # triplet: index, context, isArgument triplet = [0, 0, False] if mgenc.find_var(var, triplet): if triplet[2]: self._bc_gen.emitPUSHARGUMENT(mgenc, triplet[0], triplet[1]) else: self._bc_gen.emitPUSHLOCAL(mgenc, triplet[0], triplet[1]) else: identifier = self._universe.symbol_for(var) if mgenc.has_field(identifier): field_name = identifier mgenc.add_literal_if_absent(field_name) self._bc_gen.emitPUSHFIELD(mgenc, field_name) else: globe = identifier mgenc.add_literal_if_absent(globe) self._bc_gen.emitPUSHGLOBAL(mgenc, globe) def _gen_pop_variable(self, mgenc, var): # The purpose of this function is to find out whether the variable to be # popped off the stack is a local variable, argument, or object field. # This is done by examining all available lexical contexts, starting with # the innermost (i.e., the one represented by mgenc). # triplet: index, context, isArgument triplet = [0, 0, False] if mgenc.find_var(var, triplet): if triplet[2]: self._bc_gen.emitPOPARGUMENT(mgenc, triplet[0], triplet[1]) else: self._bc_gen.emitPOPLOCAL(mgenc, triplet[0], triplet[1]) else: self._bc_gen.emitPOPFIELD(mgenc, self._universe.symbol_for(var)) def _get_symbol_from_lexer(self): self._sym = self._lexer.get_sym() self._text = self._lexer.get_text() def _peek_for_next_symbol_from_lexer(self): self._next_sym = self._lexer.peek() def _printable_symbol(self): return self._sym == Symbol.Integer or self._sym >= Symbol.STString
class Parser(object): _single_op_syms = ( Symbol.Not, Symbol.And, Symbol.Or, Symbol.Star, Symbol.Div, Symbol.Mod, Symbol.Plus, Symbol.Equal, Symbol.More, Symbol.Less, Symbol.Comma, Symbol.At, Symbol.Per, Symbol.NONE, ) _binary_op_syms = ( Symbol.Or, Symbol.Comma, Symbol.Minus, Symbol.Equal, Symbol.Not, Symbol.And, Symbol.Or, Symbol.Star, Symbol.Div, Symbol.Mod, Symbol.Plus, Symbol.Equal, Symbol.More, Symbol.Less, Symbol.Comma, Symbol.At, Symbol.Per, Symbol.NONE, ) _keyword_selector_syms = (Symbol.Keyword, Symbol.KeywordSequence) def __init__(self, reader, universe): self._universe = universe self._lexer = Lexer(reader) self._bc_gen = BytecodeGenerator() self._sym = Symbol.NONE self._text = None self._next_sym = Symbol.NONE self._get_symbol_from_lexer() def classdef(self, cgenc): cgenc.set_name(self._universe.symbol_for(self._text)) self._expect(Symbol.Identifier) self._expect(Symbol.Equal) if self._sym == Symbol.Identifier: super_name = self._universe.symbol_for(self._text) self._accept(Symbol.Identifier) else: super_name = self._universe.symbol_for("Object") cgenc.set_super_name(super_name) # Load the super class if super_name.get_string() == "nil": # Break the dependency cycle by hard coding the values for Object cgenc.set_number_of_instance_fields_of_super(0) # Object's super class is nil, has no fields cgenc.set_number_of_class_fields_of_super(4) # Object's class has the fields of Class else: super_class = self._universe.load_class(super_name) cgenc.set_number_of_instance_fields_of_super(super_class.get_number_of_instance_fields()) cgenc.set_number_of_class_fields_of_super(super_class.get_class().get_number_of_instance_fields()) self._expect(Symbol.NewTerm) self._instance_fields(cgenc) while ( self._sym == Symbol.Identifier or self._sym == Symbol.Keyword or self._sym == Symbol.OperatorSequence or self._sym_in(self._binary_op_syms) ): mgenc = MethodGenerationContext() mgenc.set_holder(cgenc) mgenc.add_argument("self") self._method(mgenc) if mgenc.is_primitive(): cgenc.add_instance_method(mgenc.assemble_primitive(self._universe)) else: cgenc.add_instance_method(mgenc.assemble(self._universe)) if self._accept(Symbol.Separator): cgenc.set_class_side(True) self._class_fields(cgenc) while ( self._sym == Symbol.Identifier or self._sym == Symbol.Keyword or self._sym == Symbol.OperatorSequence or self._sym_in(self._binary_op_syms) ): mgenc = MethodGenerationContext() mgenc.set_holder(cgenc) mgenc.add_argument("self") self._method(mgenc) if mgenc.is_primitive(): cgenc.add_class_method(mgenc.assemble_primitive(self._universe)) else: cgenc.add_class_method(mgenc.assemble(self._universe)) self._expect(Symbol.EndTerm) def _sym_in(self, symbol_list): return self._sym in symbol_list def _accept(self, s): if self._sym == s: self._get_symbol_from_lexer() return True return False def _accept_one_of(self, symbol_list): if self._sym_in(symbol_list): self._get_symbol_from_lexer() return True return False def _expect(self, s): if self._accept(s): return True err = "Error: unexpected symbol in line %d. Expected %s, but found %s" % ( self._lexer.get_current_line_number(), Symbol.as_str(s), Symbol.as_str(self._sym), ) if self._printable_symbol(): err += " (" + self._text + ")" err += ": " + self._lexer.get_raw_buffer() raise ValueError(err) def _expect_one_of(self, symbol_list): if self._accept_one_of(symbol_list): return True expected = ", ".join([Symbol.as_str(x) for x in symbol_list]) err = "Error: unexpected symbol in line %d. Expected one of %s, but found %s" % ( self._lexer.get_current_line_number(), expected, Symbol.as_str(self._sym), ) if self._printable_symbol(): err += " (" + self._text + ")" err += ": " + self._lexer.get_raw_buffer() raise ValueError(err) def _instance_fields(self, cgenc): if self._accept(Symbol.Or): while self._sym == Symbol.Identifier: var = self._variable() cgenc.add_instance_field(self._universe.symbol_for(var)) self._expect(Symbol.Or) def _class_fields(self, cgenc): if self._accept(Symbol.Or): while self._sym == Symbol.Identifier: var = self._variable() cgenc.add_class_field(self._universe.symbol_for(var)) self._expect(Symbol.Or) def _method(self, mgenc): self._pattern(mgenc) self._expect(Symbol.Equal) if self._sym == Symbol.Primitive: mgenc.set_primitive(True) self._primitive_block() else: self._method_block(mgenc) def _primitive_block(self): self._expect(Symbol.Primitive) def _pattern(self, mgenc): if self._sym == Symbol.Identifier: self._unary_pattern(mgenc) elif self._sym == Symbol.Keyword: self._keyword_pattern(mgenc) else: self._binary_pattern(mgenc) def _unary_pattern(self, mgenc): mgenc.set_signature(self._unary_selector()) def _binary_pattern(self, mgenc): mgenc.set_signature(self._binary_selector()) mgenc.add_argument_if_absent(self._argument()) def _keyword_pattern(self, mgenc): kw = self._keyword() mgenc.add_argument_if_absent(self._argument()) while self._sym == Symbol.Keyword: kw += self._keyword() mgenc.add_argument_if_absent(self._argument()) mgenc.set_signature(self._universe.symbol_for(kw)) def _method_block(self, mgenc): self._expect(Symbol.NewTerm) self._block_contents(mgenc) # if no return has been generated so far, we can be sure there was no . # terminating the last expression, so the last expression's value must # be popped off the stack and a ^self be generated if not mgenc.is_finished(): self._bc_gen.emitPOP(mgenc) self._bc_gen.emitPUSHARGUMENT(mgenc, 0, 0) self._bc_gen.emitRETURNLOCAL(mgenc) mgenc.set_finished() self._expect(Symbol.EndTerm) def _unary_selector(self): return self._universe.symbol_for(self._identifier()) def _binary_selector(self): s = self._text if self._accept(Symbol.Or): pass elif self._accept(Symbol.Comma): pass elif self._accept(Symbol.Minus): pass elif self._accept(Symbol.Equal): pass elif self._accept_one_of(self._single_op_syms): pass elif self._accept(Symbol.OperatorSequence): pass else: self._expect(Symbol.NONE) return self._universe.symbol_for(s) def _identifier(self): s = self._text is_primitive = self._accept(Symbol.Primitive) if not is_primitive: self._expect(Symbol.Identifier) return s def _keyword(self): s = self._text self._expect(Symbol.Keyword) return s def _argument(self): return self._variable() def _block_contents(self, mgenc): if self._accept(Symbol.Or): self._locals(mgenc) self._expect(Symbol.Or) self._block_body(mgenc, False) def _locals(self, mgenc): while self._sym == Symbol.Identifier: mgenc.add_local_if_absent(self._variable()) def _block_body(self, mgenc, seenPeriod): if self._accept(Symbol.Exit): self._result(mgenc) elif self._sym == Symbol.EndBlock: if seenPeriod: # a POP has been generated which must be elided (blocks always # return the value of the last expression, regardless of # whether it was terminated with a . or not) mgenc.remove_last_bytecode() self._bc_gen.emitRETURNLOCAL(mgenc) mgenc.set_finished() elif self._sym == Symbol.EndTerm: # it does not matter whether a period has been seen, as the end of # the method has been found (EndTerm) - so it is safe to emit a # "return self" self._bc_gen.emitPUSHARGUMENT(mgenc, 0, 0) self._bc_gen.emitRETURNLOCAL(mgenc) mgenc.set_finished() else: self._expression(mgenc) if self._accept(Symbol.Period): self._bc_gen.emitPOP(mgenc) self._block_body(mgenc, True) def _result(self, mgenc): self._expression(mgenc) if mgenc.is_block_method(): self._bc_gen.emitRETURNNONLOCAL(mgenc) else: self._bc_gen.emitRETURNLOCAL(mgenc) mgenc.set_finished(True) self._accept(Symbol.Period) def _expression(self, mgenc): self._peek_for_next_symbol_from_lexer() if self._next_sym == Symbol.Assign: self._assignation(mgenc) else: self._evaluation(mgenc) def _assignation(self, mgenc): l = [] self._assignments(mgenc, l) self._evaluation(mgenc) for assignment in l: self._bc_gen.emitDUP(mgenc) for assignment in l: self._gen_pop_variable(mgenc, assignment) def _assignments(self, mgenc, l): if self._sym == Symbol.Identifier: l.append(self._assignment(mgenc)) self._peek_for_next_symbol_from_lexer() if self._next_sym == Symbol.Assign: self._assignments(mgenc, l) def _assignment(self, mgenc): v = self._variable() var = self._universe.symbol_for(v) mgenc.add_literal_if_absent(var) self._expect(Symbol.Assign) return v def _evaluation(self, mgenc): # single: superSend is_super_send = [False] self._primary(mgenc, is_super_send) if ( self._sym == Symbol.Identifier or self._sym == Symbol.Keyword or self._sym == Symbol.OperatorSequence or self._sym_in(self._binary_op_syms) ): self._messages(mgenc, is_super_send) def _primary(self, mgenc, is_super_send): is_super_send[0] = False if self._sym == Symbol.Identifier: v = self._variable() if v == "super": is_super_send[0] = True # sends to super push self as the receiver v = "self" self._gen_push_variable(mgenc, v) elif self._sym == Symbol.NewTerm: self._nested_term(mgenc) elif self._sym == Symbol.NewBlock: bgenc = MethodGenerationContext() bgenc.set_is_block_method(True) bgenc.set_holder(mgenc.get_holder()) bgenc.set_outer(mgenc) self._nested_block(bgenc) block_method = bgenc.assemble(self._universe) mgenc.add_literal(block_method) self._bc_gen.emitPUSHBLOCK(mgenc, block_method) else: self._literal(mgenc) def _variable(self): return self._identifier() def _messages(self, mgenc, is_super_send): if self._sym == Symbol.Identifier: while self._sym == Symbol.Identifier: # only the first message in a sequence can be a super send self._unary_message(mgenc, is_super_send) is_super_send[0] = False while self._sym == Symbol.OperatorSequence or self._sym_in(self._binary_op_syms): self._binary_message(mgenc, [False]) if self._sym == Symbol.Keyword: self._keyword_message(mgenc, [False]) elif self._sym == Symbol.OperatorSequence or self._sym_in(self._binary_op_syms): while self._sym == Symbol.OperatorSequence or self._sym_in(self._binary_op_syms): # only the first message in a sequence can be a super send self._binary_message(mgenc, is_super_send) is_super_send[0] = False if self._sym == Symbol.Keyword: self._keyword_message(mgenc, [False]) else: self._keyword_message(mgenc, is_super_send) def _unary_message(self, mgenc, is_super_send): msg = self._unary_selector() mgenc.add_literal_if_absent(msg) if is_super_send[0]: self._bc_gen.emitSUPERSEND(mgenc, msg) else: self._bc_gen.emitSEND(mgenc, msg) def _binary_message(self, mgenc, is_super_send): msg = self._binary_selector() mgenc.add_literal_if_absent(msg) self._binary_operand(mgenc, [False]) if is_super_send[0]: self._bc_gen.emitSUPERSEND(mgenc, msg) else: self._bc_gen.emitSEND(mgenc, msg) def _binary_operand(self, mgenc, is_super_send): self._primary(mgenc, is_super_send) while self._sym == Symbol.Identifier: self._unary_message(mgenc, is_super_send) def _keyword_message(self, mgenc, is_super_send): kw = self._keyword() self._formula(mgenc) while self._sym == Symbol.Keyword: kw += self._keyword() self._formula(mgenc) msg = self._universe.symbol_for(kw) mgenc.add_literal_if_absent(msg) if is_super_send[0]: self._bc_gen.emitSUPERSEND(mgenc, msg) else: self._bc_gen.emitSEND(mgenc, msg) def _formula(self, mgenc): is_super_send = [False] self._binary_operand(mgenc, is_super_send) # only the first message in a sequence can be a super send if self._sym == Symbol.OperatorSequence or self._sym_in(self._binary_op_syms): self._binary_message(mgenc, is_super_send) while self._sym == Symbol.OperatorSequence or self._sym_in(self._binary_op_syms): self._binary_message(mgenc, [False]) def _nested_term(self, mgenc): self._expect(Symbol.NewTerm) self._expression(mgenc) self._expect(Symbol.EndTerm) def _literal(self, mgenc): if self._sym == Symbol.Pound: self._literal_symbol(mgenc) elif self._sym == Symbol.STString: self._literal_string(mgenc) else: self._literal_number(mgenc) def _literal_number(self, mgenc): if self._sym == Symbol.Minus: val = self._negative_decimal() else: val = self._literal_decimal() if Integer.value_fits(val): lit = self._universe.new_integer(val) else: lit = self._universe.new_biginteger(val) mgenc.add_literal_if_absent(lit) self._bc_gen.emitPUSHCONSTANT(mgenc, lit) def _literal_decimal(self): return self._literal_integer() def _negative_decimal(self): self._expect(Symbol.Minus) return -self._literal_integer() def _literal_integer(self): i = long(self._text) self._expect(Symbol.Integer) return i def _literal_symbol(self, mgenc): self._expect(Symbol.Pound) if self._sym == Symbol.STString: s = self._string() symb = self._universe.symbol_for(s) else: symb = self._selector() mgenc.add_literal_if_absent(symb) self._bc_gen.emitPUSHCONSTANT(mgenc, symb) def _literal_string(self, mgenc): s = self._string() string = self._universe.new_string(s) mgenc.add_literal_if_absent(string) self._bc_gen.emitPUSHCONSTANT(mgenc, string) def _selector(self): if self._sym == Symbol.OperatorSequence or self._sym_in(self._single_op_syms): return self._binary_selector() elif self._sym == Symbol.Keyword or self._sym == Symbol.KeywordSequence: return self._keyword_selector() else: return self._unary_selector() def _keyword_selector(self): s = self._text self._expect_one_of(self._keyword_selector_syms) symb = self._universe.symbol_for(s) return symb def _string(self): s = self._text self._expect(Symbol.STString) return s def _nested_block(self, mgenc): mgenc.add_argument_if_absent("$block self") self._expect(Symbol.NewBlock) if self._sym == Symbol.Colon: self._block_pattern(mgenc) # generate Block signature block_sig = "$block method" arg_size = mgenc.get_number_of_arguments() block_sig += ":" * (arg_size - 1) mgenc.set_signature(self._universe.symbol_for(block_sig)) self._block_contents(mgenc) # if no return has been generated, we can be sure that the last # expression in the block was not terminated by ., and can generate # a return if not mgenc.is_finished(): self._bc_gen.emitRETURNLOCAL(mgenc) mgenc.set_finished(True) self._expect(Symbol.EndBlock) def _block_pattern(self, mgenc): self._block_arguments(mgenc) self._expect(Symbol.Or) def _block_arguments(self, mgenc): self._expect(Symbol.Colon) mgenc.add_argument_if_absent(self._argument()) while self._sym == Symbol.Colon: self._expect(Symbol.Colon) mgenc.add_argument_if_absent(self._argument()) def _gen_push_variable(self, mgenc, var): # The purpose of this function is to find out whether the variable to be # pushed on the stack is a local variable, argument, or object field. # This is done by examining all available lexical contexts, starting with # the innermost (i.e., the one represented by mgenc). # triplet: index, context, isArgument triplet = [0, 0, False] if mgenc.find_var(var, triplet): if triplet[2]: self._bc_gen.emitPUSHARGUMENT(mgenc, triplet[0], triplet[1]) else: self._bc_gen.emitPUSHLOCAL(mgenc, triplet[0], triplet[1]) else: identifier = self._universe.symbol_for(var) if mgenc.has_field(identifier): field_name = identifier mgenc.add_literal_if_absent(field_name) self._bc_gen.emitPUSHFIELD(mgenc, field_name) else: globe = identifier mgenc.add_literal_if_absent(globe) self._bc_gen.emitPUSHGLOBAL(mgenc, globe) def _gen_pop_variable(self, mgenc, var): # The purpose of this function is to find out whether the variable to be # popped off the stack is a local variable, argument, or object field. # This is done by examining all available lexical contexts, starting with # the innermost (i.e., the one represented by mgenc). # triplet: index, context, isArgument triplet = [0, 0, False] if mgenc.find_var(var, triplet): if triplet[2]: self._bc_gen.emitPOPARGUMENT(mgenc, triplet[0], triplet[1]) else: self._bc_gen.emitPOPLOCAL(mgenc, triplet[0], triplet[1]) else: self._bc_gen.emitPOPFIELD(mgenc, self._universe.symbol_for(var)) def _get_symbol_from_lexer(self): self._sym = self._lexer.get_sym() self._text = self._lexer.get_text() def _peek_for_next_symbol_from_lexer(self): self._next_sym = self._lexer.peek() def _printable_symbol(self): return self._sym == Symbol.Integer or self._sym >= Symbol.STString