use prolog_parser::ast::*; use prolog_parser::string_list::StringList; use prolog::instructions::*; use prolog::and_stack::*; use prolog::copier::*; use prolog::heap_iter::*; use prolog::heap_print::*; use prolog::machine::machine_errors::*; use prolog::machine::machine_state::*; use prolog::num::{Integer, Signed, ToPrimitive, Zero}; use prolog::num::bigint::{BigInt, BigUint}; use prolog::num::rational::Ratio; use prolog::or_stack::*; use std::cell::RefCell; use std::cmp::{max, Ordering}; use std::collections::{HashMap, HashSet}; use std::rc::Rc; macro_rules! try_or_fail { ($s:ident, $e:expr) => {{ match $e { Ok(val) => val, Err(msg) => { $s.throw_exception(msg); return; } } }} } impl MachineState { pub(super) fn new() -> Self { MachineState { atom_tbl: Rc::new(RefCell::new(HashSet::new())), s: 0, p: CodePtr::default(), b: 0, b0: 0, e: 0, num_of_args: 0, cp: LocalCodePtr::default(), fail: false, heap: Heap::with_capacity(256), mode: MachineMode::Write, and_stack: AndStack::new(), or_stack: OrStack::new(), registers: vec![Addr::HeapCell(0); MAX_ARITY + 1], // self.registers[0] is never used. trail: Vec::new(), tr: 0, hb: 0, block: 0, ball: Ball::new(), interms: vec![Number::default(); 256], last_call: false, flags: MachineFlags::default() } } #[inline] pub fn machine_flags(&self) -> MachineFlags { self.flags } fn next_global_index(&self) -> usize { max(if self.and_stack.len() > 0 { self.and_stack[self.e].global_index } else { 0 }, if self.b > 0 { self.or_stack[self.b - 1].global_index } else { 0 }) + 1 } pub(crate) fn store(&self, a: Addr) -> Addr { match a { Addr::HeapCell(r) => self.heap[r].as_addr(r), Addr::StackCell(fr, sc) => self.and_stack[fr][sc].clone(), addr => addr } } pub(crate) fn deref(&self, mut a: Addr) -> Addr { loop { let value = self.store(a.clone()); if value.is_ref() && value != a { a = value; continue; } return a; }; } pub(super) fn bind(&mut self, r1: Ref, a2: Addr) { let t1 = self.store(r1.as_addr()); let t2 = self.store(a2.clone()); if t1.is_ref() && (!t2.is_ref() || a2 < r1) { match r1 { Ref::StackCell(fr, sc) => self.and_stack[fr][sc] = t2, Ref::HeapCell(h) => self.heap[h] = HeapCellValue::Addr(t2) }; self.trail(r1); } else { match a2.as_var() { Some(Ref::StackCell(fr, sc)) => { self.and_stack[fr][sc] = t1; self.trail(Ref::StackCell(fr, sc)); }, Some(Ref::HeapCell(h)) => { self.heap[h] = HeapCellValue::Addr(t1); self.trail(Ref::HeapCell(h)); }, None => {} } } } pub(super) fn print_var_eq(&self, var: Rc, addr: Addr, var_dir: &HeapVarDict, fmt: Fmt, mut output: Outputter) -> Outputter where Fmt: HCValueFormatter, Outputter: HCValueOutputter { let orig_len = output.len(); output.begin_new_var(); output.append(var.as_str()); output.append(" = "); let printer = HCPrinter::from_heap_locs(&self, fmt, output, var_dir); let mut output = printer.print(addr); let bad_ending = format!("= {}", &var); if output.ends_with(&bad_ending) { output.truncate(orig_len); } output } pub(super) fn print_exception(&self, addr: Addr, var_dir: &HeapVarDict, fmt: Fmt, output: Outputter) -> Outputter where Fmt: HCValueFormatter, Outputter: HCValueOutputter { let printer = HCPrinter::from_heap_locs(&self, fmt, output, var_dir); printer.print(addr) } pub(super) fn print_term(&self, addr: Addr, fmt: Fmt, output: Outputter) -> Outputter where Fmt: HCValueFormatter, Outputter: HCValueOutputter { let printer = HCPrinter::new(&self, fmt, output); printer.print(addr) } pub(super) fn unify(&mut self, a1: Addr, a2: Addr) { let mut pdl = vec![a1, a2]; self.fail = false; while !(pdl.is_empty() || self.fail) { let d1 = self.deref(pdl.pop().unwrap()); let d2 = self.deref(pdl.pop().unwrap()); if d1 != d2 { match (self.store(d1.clone()), self.store(d2.clone())) { (Addr::HeapCell(hc), _) => self.bind(Ref::HeapCell(hc), d2), (_, Addr::HeapCell(hc)) => self.bind(Ref::HeapCell(hc), d1), (Addr::StackCell(fr, sc), _) => self.bind(Ref::StackCell(fr, sc), d2), (_, Addr::StackCell(fr, sc)) => self.bind(Ref::StackCell(fr, sc), d1), (Addr::Lis(a1), Addr::Str(a2)) | (Addr::Str(a2), Addr::Lis(a1)) => { if let &HeapCellValue::NamedStr(n2, ref f2, _) = &self.heap[a2] { if f2.as_str() == "." && n2 == 2 { pdl.push(Addr::HeapCell(a1)); pdl.push(Addr::HeapCell(a2 + 1)); pdl.push(Addr::HeapCell(a1 + 1)); pdl.push(Addr::HeapCell(a2 + 2)); continue; } } self.fail = true; }, (Addr::Lis(a1), Addr::Con(Constant::String(ref mut s))) | (Addr::Con(Constant::String(ref mut s)), Addr::Lis(a1)) if self.flags.double_quotes.is_chars() => { if let Some(c) = s.head() { pdl.push(Addr::Con(Constant::String(s.tail()))); pdl.push(Addr::HeapCell(a1 + 1)); pdl.push(Addr::Con(Constant::Char(c))); pdl.push(Addr::HeapCell(a1)); continue; } else if s.is_expandable() { let mut stepper = |c| { let new_s = s.push_char(c); pdl.push(Addr::HeapCell(a1 + 1)); pdl.push(Addr::Con(Constant::String(new_s))); }; match self.heap[a1].clone() { HeapCellValue::Addr(Addr::Con(Constant::Char(c))) => { stepper(c); continue; }, HeapCellValue::Addr(Addr::Con(Constant::Atom(ref a))) => if let Some(c) = a.as_str().chars().next() { if c.len_utf8() == a.as_str().len() { stepper(c); continue; } }, _ => {} }; } self.fail = true; }, (Addr::Con(Constant::EmptyList), Addr::Con(Constant::String(ref s))) | (Addr::Con(Constant::String(ref s)), Addr::Con(Constant::EmptyList)) if self.flags.double_quotes.is_chars() => { if s.is_expandable() && s.is_empty() { s.set_non_expandable(); continue; } self.fail = !s.is_empty(); }, (Addr::Lis(a1), Addr::Lis(a2)) => { pdl.push(Addr::HeapCell(a1)); pdl.push(Addr::HeapCell(a2)); pdl.push(Addr::HeapCell(a1 + 1)); pdl.push(Addr::HeapCell(a2 + 1)); }, (Addr::Con(Constant::String(ref mut s1)), Addr::Con(Constant::String(ref mut s2))) => { let mut stepper = |s1: &mut StringList, s2: &mut StringList| -> bool { if let Some(c1) = s1.head() { if let Some(c2) = s2.head() { if c1 == c2 { pdl.push(Addr::Con(Constant::String(s1.tail()))); pdl.push(Addr::Con(Constant::String(s2.tail()))); return true; } } else if s2.is_expandable() { pdl.push(Addr::Con(Constant::String(s2.push_char(c1)))); pdl.push(Addr::Con(Constant::String(s1.tail()))); return true; } } else if s1.is_expandable() { if let Some(c) = s2.head() { pdl.push(Addr::Con(Constant::String(s1.push_char(c)))); pdl.push(Addr::Con(Constant::String(s2.tail()))); } else if s2.is_expandable() { return s1 == s2; } else { s1.set_non_expandable(); } return true; } else if s2.head().is_none() { s2.set_non_expandable(); return true; } false }; self.fail = !(stepper(s1, s2) || stepper(s2, s1)); }, (Addr::Con(ref c1), Addr::Con(ref c2)) => if c1 != c2 { self.fail = true; }, (Addr::Str(a1), Addr::Str(a2)) => { let r1 = &self.heap[a1]; let r2 = &self.heap[a2]; if let &HeapCellValue::NamedStr(n1, ref f1, _) = r1 { if let &HeapCellValue::NamedStr(n2, ref f2, _) = r2 { if n1 == n2 && *f1 == *f2 { for i in 1 .. n1 + 1 { pdl.push(Addr::HeapCell(a1 + i)); pdl.push(Addr::HeapCell(a2 + i)); } continue; } } } self.fail = true; }, _ => self.fail = true }; } } } fn trail(&mut self, r: Ref) { match r { Ref::HeapCell(hc) => if hc < self.hb { self.trail.push(r); self.tr += 1; }, Ref::StackCell(fr, _) => { let fr_gi = self.and_stack[fr].global_index; let b_gi = if !self.or_stack.is_empty() { if self.b > 0 { let b = self.b - 1; self.or_stack[b].global_index } else { 0 } } else { 0 }; if fr_gi < b_gi { self.trail.push(r); self.tr += 1; } } } } pub(super) fn unwind_trail(&mut self, a1: usize, a2: usize) { for i in a1 .. a2 { match self.trail[i] { Ref::HeapCell(r) => self.heap[r] = HeapCellValue::Addr(Addr::HeapCell(r)), Ref::StackCell(fr, sc) => self.and_stack[fr][sc] = Addr::StackCell(fr, sc) } } } pub(super) fn tidy_trail(&mut self) { if self.b == 0 { return; } let b = self.b - 1; let mut i = self.or_stack[b].tr; while i < self.tr { let tr_i = self.trail[i]; let hb = self.hb; match tr_i { Ref::HeapCell(tr_i) => if tr_i < hb { //|| ((h < tr_i) && tr_i < b) { i += 1; } else { let tr = self.tr; let val = self.trail[tr - 1]; self.trail[i] = val; self.tr -= 1; }, Ref::StackCell(fr, _) => { let b = self.b - 1; let fr_gi = self.and_stack[fr].global_index; let b_gi = if !self.or_stack.is_empty() { self.or_stack[b].global_index } else { 0 }; if fr_gi < b_gi { i += 1; } else { let tr = self.tr; let val = self.trail[tr - 1]; self.trail[i] = val; self.tr -= 1; } } }; } } pub(super) fn write_constant_to_var(&mut self, addr: Addr, c: Constant) { match self.store(self.deref(addr)) { Addr::HeapCell(hc) => { self.heap[hc] = HeapCellValue::Addr(Addr::Con(c.clone())); self.trail(Ref::HeapCell(hc)); }, Addr::StackCell(fr, sc) => { self.and_stack[fr][sc] = Addr::Con(c.clone()); self.trail(Ref::StackCell(fr, sc)); }, Addr::Con(Constant::String(ref mut s)) => self.fail = match c { Constant::EmptyList if self.flags.double_quotes.is_chars() => !s.is_empty(), Constant::String(ref s2) if s.is_empty() && s.is_expandable() => { s.append(s2); false }, Constant::String(s2) => *s != s2, _ => true }, Addr::Con(c1) => { if c1 != c { self.fail = true; } }, _ => self.fail = true }; } pub(super) fn get_number(&self, at: &ArithmeticTerm) -> Result { match at { &ArithmeticTerm::Reg(r) => self.arith_eval_by_metacall(r), &ArithmeticTerm::Interm(i) => Ok(self.interms[i-1].clone()), &ArithmeticTerm::Number(ref n) => Ok(n.clone()), } } fn get_rational(&self, at: &ArithmeticTerm, caller: &MachineStub) -> Result>, MachineStub> { let n = self.get_number(at)?; match n { Number::Rational(r) => Ok(r), Number::Float(fl) => if let Some(r) = Ratio::from_float(fl.into_inner()) { Ok(Rc::new(r)) } else { Err(self.error_form(MachineError::instantiation_error(), caller.clone())) }, Number::Integer(bi) => Ok(Rc::new(Ratio::from_integer((*bi).clone()))) } } fn signed_bitwise_op(&self, n1: &BigInt, n2: &BigInt, f: Op) -> Rc where Op: FnOnce(&BigUint, &BigUint) -> BigUint { let n1_b = n1.to_signed_bytes_le(); let n2_b = n2.to_signed_bytes_le(); let u_n1 = BigUint::from_bytes_le(&n1_b); let u_n2 = BigUint::from_bytes_le(&n2_b); Rc::new(BigInt::from_signed_bytes_le(&f(&u_n1, &u_n2).to_bytes_le())) } pub(super) fn arith_eval_by_metacall(&self, r: RegType) -> Result { let a = self[r].clone(); let caller = MachineError::functor_stub(clause_name!("(is)"), 2); let mut interms: Vec = Vec::with_capacity(64); for heap_val in self.post_order_iter(a) { match heap_val { HeapCellValue::NamedStr(2, name, Some(Fixity::In)) => { let a2 = interms.pop().unwrap(); let a1 = interms.pop().unwrap(); match name.as_str() { "+" => interms.push(a1 + a2), "-" => interms.push(a1 - a2), "*" => interms.push(a1 * a2), "/" => interms.push(self.div(a1, a2)?), "**" => interms.push(self.pow(a1, a2)?), "rdiv" => { let r1 = self.get_rational(&ArithmeticTerm::Number(a1), &caller)?; let r2 = self.get_rational(&ArithmeticTerm::Number(a2), &caller)?; let result = Number::Rational(self.rdiv(r1, r2)?); interms.push(result) }, "//" => interms.push(Number::Integer(self.idiv(a1, a2)?)), "div" => interms.push(Number::Integer(self.fidiv(a1, a2)?)), ">>" => interms.push(Number::Integer(self.shr(a1, a2)?)), "<<" => interms.push(Number::Integer(self.shl(a1, a2)?)), "/\\" => interms.push(Number::Integer(self.and(a1, a2)?)), "\\/" => interms.push(Number::Integer(self.or(a1, a2)?)), "xor" => interms.push(Number::Integer(self.xor(a1, a2)?)), "mod" => interms.push(Number::Integer(self.modulus(a1, a2)?)), "rem" => interms.push(Number::Integer(self.remainder(a1, a2)?)), _ => return Err(self.error_form(MachineError::instantiation_error(), caller)) } }, HeapCellValue::NamedStr(1, name, Some(Fixity::Pre)) => { let a1 = interms.pop().unwrap(); match name.as_str() { "-" => interms.push(- a1), _ => return Err(self.error_form(MachineError::instantiation_error(), caller)) } }, HeapCellValue::Addr(Addr::Con(Constant::Number(n))) => interms.push(n), _ => return Err(self.error_form(MachineError::instantiation_error(), caller)) } }; Ok(interms.pop().unwrap()) } fn rdiv(&self, r1: Rc>, r2: Rc>) -> Result>, MachineStub> { let stub = MachineError::functor_stub(clause_name!("(rdiv)"), 2); if *r2 == Ratio::zero() { Err(self.error_form(MachineError::evaluation_error(EvalError::ZeroDivisor), stub)) } else { Ok(Rc::new(&*r1 / &*r2)) } } fn fidiv(&self, n1: Number, n2: Number) -> Result, MachineStub> { let stub = MachineError::functor_stub(clause_name!("(div)"), 2); match (n1, n2) { (Number::Integer(n1), Number::Integer(n2)) => if *n2 == BigInt::zero() { Err(self.error_form(MachineError::evaluation_error(EvalError::ZeroDivisor), stub)) } else { Ok(Rc::new(n1.div_floor(&n2))) }, (Number::Integer(_), n2) => Err(self.error_form(MachineError::type_error(ValidType::Integer, Addr::Con(Constant::Number(n2))), stub)), (n1, _) => Err(self.error_form(MachineError::type_error(ValidType::Integer, Addr::Con(Constant::Number(n1))), stub)) } } fn idiv(&self, n1: Number, n2: Number) -> Result, MachineStub> { let stub = MachineError::functor_stub(clause_name!("(//)"), 2); match (n1, n2) { (Number::Integer(n1), Number::Integer(n2)) => if *n2 == BigInt::zero() { Err(self.error_form(MachineError::evaluation_error(EvalError::ZeroDivisor), stub)) } else { Ok(Rc::new(&*n1 / &*n2)) }, (Number::Integer(_), n2) => Err(self.error_form(MachineError::type_error(ValidType::Integer, Addr::Con(Constant::Number(n2))), stub)), (n1, _) => Err(self.error_form(MachineError::type_error(ValidType::Integer, Addr::Con(Constant::Number(n1))), stub)) } } fn div(&self, n1: Number, n2: Number) -> Result { let stub = MachineError::functor_stub(clause_name!("(/)"), 2); if n2.is_zero() { Err(self.error_form(MachineError::evaluation_error(EvalError::ZeroDivisor), stub)) } else { Ok(n1 / n2) } } fn pow(&self, n1: Number, n2: Number) -> Result { match n1.pow(n2) { Ok(result) => Ok(result), Err(_) => { let stub = MachineError::functor_stub(clause_name!("**"), 2); Err(self.error_form(MachineError::evaluation_error(EvalError::NoRoots), stub)) } } } fn shr(&self, n1: Number, n2: Number) -> Result, MachineStub> { let stub = MachineError::functor_stub(clause_name!("(>>)"), 2); match (n1, n2) { (Number::Integer(n1), Number::Integer(n2)) => match n2.to_usize() { Some(n2) => Ok(Rc::new(&*n1 >> n2)), _ => Ok(Rc::new(&*n1 >> usize::max_value())) }, (Number::Integer(_), n2) => Err(self.error_form(MachineError::type_error(ValidType::Integer, Addr::Con(Constant::Number(n2))), stub)), (n1, _) => Err(self.error_form(MachineError::type_error(ValidType::Integer, Addr::Con(Constant::Number(n1))), stub)) } } fn shl(&self, n1: Number, n2: Number) -> Result, MachineStub> { let stub = MachineError::functor_stub(clause_name!("(<<)"), 2); match (n1, n2) { (Number::Integer(n1), Number::Integer(n2)) => match n2.to_usize() { Some(n2) => Ok(Rc::new(&*n1 << n2)), _ => Ok(Rc::new(&*n1 << usize::max_value())) }, (Number::Integer(_), n2) => Err(self.error_form(MachineError::type_error(ValidType::Integer, Addr::Con(Constant::Number(n2))), stub)), (n1, _) => Err(self.error_form(MachineError::type_error(ValidType::Integer, Addr::Con(Constant::Number(n1))), stub)) } } fn xor(&self, n1: Number, n2: Number) -> Result, MachineStub> { let stub = MachineError::functor_stub(clause_name!("(xor)"), 2); match (n1, n2) { (Number::Integer(n1), Number::Integer(n2)) => Ok(self.signed_bitwise_op(&*n1, &*n2, |u_n1, u_n2| u_n1 ^ u_n2)), (Number::Integer(_), n2) => Err(self.error_form(MachineError::type_error(ValidType::Integer, Addr::Con(Constant::Number(n2))), stub)), (n1, _) => Err(self.error_form(MachineError::type_error(ValidType::Integer, Addr::Con(Constant::Number(n1))), stub)) } } fn and(&self, n1: Number, n2: Number) -> Result, MachineStub> { let stub = MachineError::functor_stub(clause_name!("(/\\)"), 2); match (n1, n2) { (Number::Integer(n1), Number::Integer(n2)) => Ok(self.signed_bitwise_op(&*n1, &*n2, |u_n1, u_n2| u_n1 & u_n2)), (Number::Integer(_), n2) => Err(self.error_form(MachineError::type_error(ValidType::Integer, Addr::Con(Constant::Number(n2))), stub)), (n1, _) => Err(self.error_form(MachineError::type_error(ValidType::Integer, Addr::Con(Constant::Number(n1))), stub)) } } fn modulus(&self, n1: Number, n2: Number) -> Result, MachineStub> { let stub = MachineError::functor_stub(clause_name!("(mod)"), 2); match (n1, n2) { (Number::Integer(n1), Number::Integer(n2)) => if *n2 == BigInt::zero() { Err(self.error_form(MachineError::evaluation_error(EvalError::ZeroDivisor), stub)) } else { Ok(Rc::new(n1.mod_floor(&n2))) }, (Number::Integer(_), n2) => Err(self.error_form(MachineError::type_error(ValidType::Integer, Addr::Con(Constant::Number(n2))), stub)), (n1, _) => Err(self.error_form(MachineError::type_error(ValidType::Integer, Addr::Con(Constant::Number(n1))), stub)) } } fn remainder(&self, n1: Number, n2: Number) -> Result, MachineStub> { let stub = MachineError::functor_stub(clause_name!("(rem)"), 2); match (n1, n2) { (Number::Integer(n1), Number::Integer(n2)) => if *n2 == BigInt::zero() { Err(self.error_form(MachineError::evaluation_error(EvalError::ZeroDivisor), stub)) } else { Ok(Rc::new(&*n1 % &*n2)) }, (Number::Integer(_), n2) => Err(self.error_form(MachineError::type_error(ValidType::Integer, Addr::Con(Constant::Number(n2))), stub)), (n1, _) => Err(self.error_form(MachineError::type_error(ValidType::Integer, Addr::Con(Constant::Number(n1))), stub)) } } fn or(&self, n1: Number, n2: Number) -> Result, MachineStub> { let stub = MachineError::functor_stub(clause_name!("(\\/)"), 2); match (n1, n2) { (Number::Integer(n1), Number::Integer(n2)) => Ok(self.signed_bitwise_op(&*n1, &*n2, |u_n1, u_n2| u_n1 & u_n2)), (Number::Integer(_), n2) => Err(self.error_form(MachineError::type_error(ValidType::Integer, Addr::Con(Constant::Number(n2))), stub)), (n1, _) => Err(self.error_form(MachineError::type_error(ValidType::Integer, Addr::Con(Constant::Number(n1))), stub)) } } pub(super) fn execute_arith_instr(&mut self, instr: &ArithmeticInstruction) { match instr { &ArithmeticInstruction::Add(ref a1, ref a2, t) => { let n1 = try_or_fail!(self, self.get_number(a1)); let n2 = try_or_fail!(self, self.get_number(a2)); self.interms[t - 1] = n1 + n2; self.p += 1; }, &ArithmeticInstruction::Sub(ref a1, ref a2, t) => { let n1 = try_or_fail!(self, self.get_number(a1)); let n2 = try_or_fail!(self, self.get_number(a2)); self.interms[t - 1] = n1 - n2; self.p += 1; }, &ArithmeticInstruction::Mul(ref a1, ref a2, t) => { let n1 = try_or_fail!(self, self.get_number(a1)); let n2 = try_or_fail!(self, self.get_number(a2)); self.interms[t - 1] = n1 * n2; self.p += 1; }, &ArithmeticInstruction::Pow(ref a1, ref a2, t) => { let n1 = try_or_fail!(self, self.get_number(a1)); let n2 = try_or_fail!(self, self.get_number(a2)); self.interms[t - 1] = try_or_fail!(self, self.pow(n1, n2)); self.p += 1; }, &ArithmeticInstruction::RDiv(ref a1, ref a2, t) => { let stub = MachineError::functor_stub(clause_name!("(rdiv)"), 2); let r1 = try_or_fail!(self, self.get_rational(a1, &stub)); let r2 = try_or_fail!(self, self.get_rational(a2, &stub)); self.interms[t - 1] = Number::Rational(try_or_fail!(self, self.rdiv(r1, r2))); self.p += 1; }, &ArithmeticInstruction::FIDiv(ref a1, ref a2, t) => { let n1 = try_or_fail!(self, self.get_number(a1)); let n2 = try_or_fail!(self, self.get_number(a2)); self.interms[t - 1] = Number::Integer(try_or_fail!(self, self.fidiv(n1, n2))); self.p += 1; }, &ArithmeticInstruction::IDiv(ref a1, ref a2, t) => { let n1 = try_or_fail!(self, self.get_number(a1)); let n2 = try_or_fail!(self, self.get_number(a2)); self.interms[t - 1] = Number::Integer(try_or_fail!(self, self.idiv(n1, n2))); self.p += 1; }, &ArithmeticInstruction::Abs(ref a1, t) => { let n1 = try_or_fail!(self, self.get_number(a1)); self.interms[t - 1] = n1.abs(); self.p += 1; }, &ArithmeticInstruction::Neg(ref a1, t) => { let n1 = try_or_fail!(self, self.get_number(a1)); self.interms[t - 1] = - n1; self.p += 1; }, &ArithmeticInstruction::Div(ref a1, ref a2, t) => { let n1 = try_or_fail!(self, self.get_number(a1)); let n2 = try_or_fail!(self, self.get_number(a2)); self.interms[t - 1] = try_or_fail!(self, self.div(n1, n2)); self.p += 1; }, &ArithmeticInstruction::Shr(ref a1, ref a2, t) => { let n1 = try_or_fail!(self, self.get_number(a1)); let n2 = try_or_fail!(self, self.get_number(a2)); self.interms[t - 1] = Number::Integer(try_or_fail!(self, self.shr(n1, n2))); self.p += 1; }, &ArithmeticInstruction::Shl(ref a1, ref a2, t) => { let n1 = try_or_fail!(self, self.get_number(a1)); let n2 = try_or_fail!(self, self.get_number(a2)); self.interms[t - 1] = Number::Integer(try_or_fail!(self, self.shl(n1, n2))); self.p += 1; }, &ArithmeticInstruction::Xor(ref a1, ref a2, t) => { let n1 = try_or_fail!(self, self.get_number(a1)); let n2 = try_or_fail!(self, self.get_number(a2)); self.interms[t - 1] = Number::Integer(try_or_fail!(self, self.xor(n1, n2))); self.p += 1; }, &ArithmeticInstruction::And(ref a1, ref a2, t) => { let n1 = try_or_fail!(self, self.get_number(a1)); let n2 = try_or_fail!(self, self.get_number(a2)); self.interms[t - 1] = Number::Integer(try_or_fail!(self, self.and(n1, n2))); self.p += 1; }, &ArithmeticInstruction::Or(ref a1, ref a2, t) => { let n1 = try_or_fail!(self, self.get_number(a1)); let n2 = try_or_fail!(self, self.get_number(a2)); self.interms[t - 1] = Number::Integer(try_or_fail!(self, self.or(n1, n2))); self.p += 1; }, &ArithmeticInstruction::Mod(ref a1, ref a2, t) => { let n1 = try_or_fail!(self, self.get_number(a1)); let n2 = try_or_fail!(self, self.get_number(a2)); self.interms[t - 1] = Number::Integer(try_or_fail!(self, self.modulus(n1, n2))); self.p += 1; }, &ArithmeticInstruction::Rem(ref a1, ref a2, t) => { let n1 = try_or_fail!(self, self.get_number(a1)); let n2 = try_or_fail!(self, self.get_number(a2)); self.interms[t - 1] = Number::Integer(try_or_fail!(self, self.remainder(n1, n2))); self.p += 1; } }; } pub(super) fn execute_fact_instr(&mut self, instr: &FactInstruction) { match instr { &FactInstruction::GetConstant(_, ref c, reg) => { let addr = self[reg].clone(); self.write_constant_to_var(addr, c.clone()); }, &FactInstruction::GetList(_, reg) => { let addr = self.store(self.deref(self[reg].clone())); match addr { Addr::Con(Constant::String(ref s)) if self.flags.double_quotes.is_chars() => { let h = self.heap.h; if let Some(c) = s.head() { self.heap.push(HeapCellValue::Addr(Addr::Con(Constant::Char(c)))); self.heap.push(HeapCellValue::Addr(Addr::Con(Constant::String(s.tail())))); self.s = h; self.mode = MachineMode::Read; } else if s.is_expandable() { self.heap.push(HeapCellValue::Addr(Addr::Con(Constant::String(s.clone())))); self.s = h; self.mode = MachineMode::Read; } else { self.fail = true; } }, Addr::HeapCell(hc) => { let h = self.heap.h; self.heap.push(HeapCellValue::Addr(Addr::Lis(h+1))); self.bind(Ref::HeapCell(hc), Addr::HeapCell(h)); self.mode = MachineMode::Write; }, Addr::StackCell(fr, sc) => { let h = self.heap.h; self.heap.push(HeapCellValue::Addr(Addr::Lis(h+1))); self.bind(Ref::StackCell(fr, sc), Addr::HeapCell(h)); self.mode = MachineMode::Write; }, Addr::Lis(a) => { self.s = a; self.mode = MachineMode::Read; }, _ => self.fail = true }; }, &FactInstruction::GetStructure(ref ct, arity, reg) => { let addr = self.deref(self[reg].clone()); match self.store(addr.clone()) { Addr::Str(a) => { let result = &self.heap[a]; if let &HeapCellValue::NamedStr(narity, ref s, _) = result { if narity == arity && ct.name() == *s { self.s = a + 1; self.mode = MachineMode::Read; } else { self.fail = true; } } }, Addr::HeapCell(_) | Addr::StackCell(_, _) => { let h = self.heap.h; self.heap.push(HeapCellValue::Addr(Addr::Str(h + 1))); self.heap.push(HeapCellValue::NamedStr(arity, ct.name(), ct.fixity())); self.bind(addr.as_var().unwrap(), Addr::HeapCell(h)); self.mode = MachineMode::Write; }, _ => self.fail = true }; }, &FactInstruction::GetVariable(norm, arg) => self[norm] = self.registers[arg].clone(), &FactInstruction::GetValue(norm, arg) => { let norm_addr = self[norm].clone(); let reg_addr = self.registers[arg].clone(); self.unify(norm_addr, reg_addr); }, &FactInstruction::UnifyConstant(ref c) => { match self.mode { MachineMode::Read => { let addr = Addr::HeapCell(self.s); self.write_constant_to_var(addr, c.clone()); }, MachineMode::Write => { self.heap.push(HeapCellValue::Addr(Addr::Con(c.clone()))); } }; self.s += 1; }, &FactInstruction::UnifyVariable(reg) => { match self.mode { MachineMode::Read => self[reg] = self.heap[self.s].as_addr(self.s), MachineMode::Write => { let h = self.heap.h; self.heap.push(HeapCellValue::Addr(Addr::HeapCell(h))); self[reg] = Addr::HeapCell(h); } }; self.s += 1; }, &FactInstruction::UnifyLocalValue(reg) => { let s = self.s; match self.mode { MachineMode::Read => { let reg_addr = self[reg].clone(); self.unify(reg_addr, Addr::HeapCell(s)); }, MachineMode::Write => { let addr = self.deref(self[reg].clone()); let h = self.heap.h; if let Addr::HeapCell(hc) = addr { if hc < h { let val = self.heap[hc].clone(); self.heap.push(val); self.s += 1; return; } } self.heap.push(HeapCellValue::Addr(Addr::HeapCell(h))); self.bind(Ref::HeapCell(h), addr); } }; self.s += 1; }, &FactInstruction::UnifyValue(reg) => { let s = self.s; match self.mode { MachineMode::Read => { let reg_addr = self[reg].clone(); self.unify(reg_addr, Addr::HeapCell(s)); }, MachineMode::Write => { let heap_val = self.store(self[reg].clone()); self.heap.push(HeapCellValue::Addr(heap_val)); } }; self.s += 1; }, &FactInstruction::UnifyVoid(n) => { match self.mode { MachineMode::Read => self.s += n, MachineMode::Write => { let h = self.heap.h; for i in h .. h + n { self.heap.push(HeapCellValue::Addr(Addr::HeapCell(i))); } } }; } }; } pub(super) fn execute_indexing_instr(&mut self, instr: &IndexingInstruction) { match instr { &IndexingInstruction::SwitchOnTerm(v, c, l, s) => { let a1 = self.registers[1].clone(); let addr = self.store(self.deref(a1)); let offset = match addr { Addr::HeapCell(_) | Addr::StackCell(_, _) => v, Addr::Con(Constant::String(_)) if self.flags.double_quotes.is_chars() => l, Addr::Con(_) => c, Addr::Lis(_) => l, Addr::Str(_) => s }; match offset { 0 => self.fail = true, o => self.p += o }; }, &IndexingInstruction::SwitchOnConstant(_, ref hm) => { let a1 = self.registers[1].clone(); let addr = self.store(self.deref(a1)); let offset = match addr { Addr::Con(constant) => { match hm.get(&constant) { Some(offset) => *offset, _ => 0 } }, _ => 0 }; match offset { 0 => self.fail = true, o => self.p += o, }; }, &IndexingInstruction::SwitchOnStructure(_, ref hm) => { let a1 = self.registers[1].clone(); let addr = self.store(self.deref(a1)); let offset = match addr { Addr::Str(s) => { if let &HeapCellValue::NamedStr(arity, ref name, _) = &self.heap[s] { match hm.get(&(name.clone(), arity)) { Some(offset) => *offset, _ => 0 } } else { 0 } }, _ => 0 }; match offset { 0 => self.fail = true, o => self.p += o }; } }; } pub(super) fn execute_query_instr(&mut self, instr: &QueryInstruction) { match instr { &QueryInstruction::GetVariable(norm, arg) => self[norm] = self.registers[arg].clone(), &QueryInstruction::PutConstant(_, ref constant, reg) => self[reg] = Addr::Con(constant.clone()), &QueryInstruction::PutList(_, reg) => self[reg] = Addr::Lis(self.heap.h), &QueryInstruction::PutStructure(ref ct, arity, reg) => { let h = self.heap.h; self.heap.push(HeapCellValue::NamedStr(arity, ct.name(), ct.fixity())); self[reg] = Addr::Str(h); }, &QueryInstruction::PutUnsafeValue(n, arg) => { let e = self.e; let addr = self.deref(Addr::StackCell(e, n)); if addr.is_protected(e) { self.registers[arg] = self.store(addr); } else { let h = self.heap.h; self.heap.push(HeapCellValue::Addr(Addr::HeapCell(h))); self.bind(Ref::HeapCell(h), addr); self.registers[arg] = self.heap[h].as_addr(h); } }, &QueryInstruction::PutValue(norm, arg) => self.registers[arg] = self[norm].clone(), &QueryInstruction::PutVariable(norm, arg) => { match norm { RegType::Perm(n) => { let e = self.e; self[norm] = Addr::StackCell(e, n); self.registers[arg] = self[norm].clone(); }, RegType::Temp(_) => { let h = self.heap.h; self.heap.push(HeapCellValue::Addr(Addr::HeapCell(h))); self[norm] = Addr::HeapCell(h); self.registers[arg] = Addr::HeapCell(h); } }; }, &QueryInstruction::SetConstant(ref c) => { self.heap.push(HeapCellValue::Addr(Addr::Con(c.clone()))); }, &QueryInstruction::SetLocalValue(reg) => { let addr = self.deref(self[reg].clone()); let h = self.heap.h; if let Addr::HeapCell(hc) = addr { if hc < h { self.heap.push(HeapCellValue::Addr(addr)); return; } } self.heap.push(HeapCellValue::Addr(Addr::HeapCell(h))); self.bind(Ref::HeapCell(h), addr); }, &QueryInstruction::SetVariable(reg) => { let h = self.heap.h; self.heap.push(HeapCellValue::Addr(Addr::HeapCell(h))); self[reg] = Addr::HeapCell(h); }, &QueryInstruction::SetValue(reg) => { let heap_val = self[reg].clone(); self.heap.push(HeapCellValue::Addr(heap_val)); }, &QueryInstruction::SetVoid(n) => { let h = self.heap.h; for i in h .. h + n { self.heap.push(HeapCellValue::Addr(Addr::HeapCell(i))); } } } } pub(super) fn handle_internal_call_n(&mut self, arity: usize) { let arity = arity + 1; let pred = self.registers[1].clone(); for i in 2 .. arity { self.registers[i-1] = self.registers[i].clone(); } if arity > 1 { self.registers[arity - 1] = pred; return; } self.fail = true; } pub(super) fn set_ball(&mut self) { let addr = self[temp_v!(1)].clone(); self.ball.boundary = self.heap.h; let mut duplicator = DuplicateBallTerm::new(self); duplicator.duplicate_term(addr); } pub(super) fn setup_call_n(&mut self, arity: usize) -> Option { let stub = MachineError::functor_stub(clause_name!("call"), arity + 1); let addr = self.store(self.deref(self.registers[arity].clone())); let (name, narity) = match addr { Addr::Str(a) => { let result = self.heap[a].clone(); if let HeapCellValue::NamedStr(narity, name, _) = result { if narity + arity > 63 { let representation_error = self.error_form(MachineError::representation_error(RepFlag::MaxArity), stub); self.throw_exception(representation_error); return None; } for i in (1 .. arity).rev() { self.registers[i + narity] = self.registers[i].clone(); } for i in 1 .. narity + 1 { self.registers[i] = self.heap[a + i].as_addr(a + i); } (name, narity) } else { self.fail = true; return None; } }, Addr::Con(Constant::Atom(name)) => (name, 0), Addr::HeapCell(_) | Addr::StackCell(_, _) => { let instantiation_error = self.error_form(MachineError::instantiation_error(), stub); self.throw_exception(instantiation_error); return None; }, _ => { let type_error = self.error_form(MachineError::type_error(ValidType::Callable, addr), stub); self.throw_exception(type_error); return None; } }; Some((name, arity + narity - 1)) } pub(super) fn unwind_stack(&mut self) { self.b = self.block; self.or_stack.truncate(self.b); self.fail = true; } fn heap_ball_boundary_diff(&self) -> usize { if self.ball.boundary > self.heap.h { self.ball.boundary - self.heap.h } else { self.heap.h - self.ball.boundary } } pub(super) fn copy_and_align_ball_to_heap(&mut self) -> usize { let diff = self.heap_ball_boundary_diff(); for heap_value in self.ball.stub.iter().cloned() { self.heap.push(match heap_value { HeapCellValue::Addr(addr) => HeapCellValue::Addr(addr - diff), _ => heap_value }); } diff } pub(crate) fn is_cyclic_term(&self, addr: Addr) -> bool { let mut seen = HashSet::new(); let mut fail = false; let mut iter = self.pre_order_iter(addr); loop { if let Some(addr) = iter.stack().last() { if !seen.contains(addr) { seen.insert(addr.clone()); } else { fail = true; break; } } if iter.next().is_none() { break; } } fail } // arg(+N, +Term, ?Arg) pub(super) fn try_arg(&mut self) -> CallResult { let stub = MachineError::functor_stub(clause_name!("arg"), 3); let n = self.store(self.deref(self[temp_v!(1)].clone())); match n { Addr::HeapCell(_) | Addr::StackCell(..) => // 8.5.2.3 a) return Err(self.error_form(MachineError::instantiation_error(), stub)), Addr::Con(Constant::Number(Number::Integer(n))) => { if n.is_negative() { // 8.5.2.3 e) let n = Addr::Con(Constant::Number(Number::Integer(n))); let dom_err = MachineError::domain_error(DomainError::NotLessThanZero, n); return Err(self.error_form(dom_err, stub)); } let n = match n.to_usize() { Some(n) => n, None => { self.fail = true; return Ok(()); } }; let term = self.store(self.deref(self[temp_v!(2)].clone())); match term { Addr::HeapCell(_) | Addr::StackCell(..) => // 8.5.2.3 b) return Err(self.error_form(MachineError::instantiation_error(), stub)), Addr::Str(o) => match self.heap[o].clone() { HeapCellValue::NamedStr(arity, _, _) if 1 <= n && n <= arity => { let a3 = self[temp_v!(3)].clone(); let h_a = Addr::HeapCell(o + n); self.unify(a3, h_a); }, _ => self.fail = true }, Addr::Lis(l) => if n == 1 || n == 2 { let a3 = self[temp_v!(3)].clone(); let h_a = Addr::HeapCell(l + n - 1); self.unify(a3, h_a); } else { self.fail = true; }, _ => // 8.5.2.3 d) return Err(self.error_form(MachineError::type_error(ValidType::Compound, term), stub)) } }, _ => // 8.5.2.3 c) return Err(self.error_form(MachineError::type_error(ValidType::Integer, n), stub)) } Ok(()) } fn compare_numbers(&mut self, cmp: CompareNumberQT, n1: Number, n2: Number) { let ordering = n1.cmp(&n2); self.fail = match cmp { CompareNumberQT::GreaterThan if ordering == Ordering::Greater => false, CompareNumberQT::GreaterThanOrEqual if ordering != Ordering::Less => false, CompareNumberQT::LessThan if ordering == Ordering::Less => false, CompareNumberQT::LessThanOrEqual if ordering != Ordering::Greater => false, CompareNumberQT::NotEqual if ordering != Ordering::Equal => false, CompareNumberQT::Equal if ordering == Ordering::Equal => false, _ => true }; self.p += 1; } pub(super) fn compare_term(&mut self, qt: CompareTermQT) { let a1 = self[temp_v!(1)].clone(); let a2 = self[temp_v!(2)].clone(); match self.compare_term_test(&a1, &a2) { Ordering::Greater => match qt { CompareTermQT::GreaterThan | CompareTermQT::GreaterThanOrEqual => return, _ => self.fail = true }, Ordering::Equal => match qt { CompareTermQT::GreaterThanOrEqual | CompareTermQT::LessThanOrEqual => return, _ => self.fail = true }, Ordering::Less => match qt { CompareTermQT::LessThan | CompareTermQT::LessThanOrEqual => return, _ => self.fail = true } }; } // returns true on failure. pub(super) fn eq_test(&self) -> bool { let a1 = self[temp_v!(1)].clone(); let a2 = self[temp_v!(2)].clone(); let iter = self.zipped_acyclic_pre_order_iter(a1, a2); for (v1, v2) in iter { match (v1, v2) { (HeapCellValue::NamedStr(ar1, n1, _), HeapCellValue::NamedStr(ar2, n2, _)) => if ar1 != ar2 || n1 != n2 { return true; }, (HeapCellValue::Addr(Addr::Lis(_)), HeapCellValue::Addr(Addr::Lis(_))) => continue, (HeapCellValue::Addr(a1), HeapCellValue::Addr(a2)) => if a1 != a2 { return true; }, _ => return true } } false } pub(super) fn compare_term_test(&self, a1: &Addr, a2: &Addr) -> Ordering { let iter = self.zipped_acyclic_pre_order_iter(a1.clone(), a2.clone()); for (v1, v2) in iter { match (v1, v2) { (HeapCellValue::Addr(Addr::Lis(_)), HeapCellValue::Addr(Addr::Con(Constant::String(_)))) | (HeapCellValue::Addr(Addr::Con(Constant::String(_))), HeapCellValue::Addr(Addr::Lis(_))) if self.flags.double_quotes.is_chars() => {}, (HeapCellValue::Addr(Addr::Con(Constant::EmptyList)), HeapCellValue::Addr(Addr::Con(Constant::String(ref s)))) if self.flags.double_quotes.is_chars() => if s.is_empty() { return Ordering::Equal; } else { return Ordering::Greater; }, (HeapCellValue::Addr(Addr::Con(Constant::Atom(atom))), HeapCellValue::Addr(Addr::Con(Constant::Char(c)))) => return if atom.as_str().chars().count() == 1 { atom.as_str().chars().next().cmp(&Some(c)) } else { Ordering::Greater }, (HeapCellValue::Addr(Addr::Con(Constant::Char(c))), HeapCellValue::Addr(Addr::Con(Constant::Atom(atom)))) => return if atom.as_str().chars().count() == 1 { Some(c).cmp(&atom.as_str().chars().next()) } else { Ordering::Less }, (HeapCellValue::Addr(Addr::Con(Constant::String(ref s))), HeapCellValue::Addr(Addr::Con(Constant::EmptyList))) if self.flags.double_quotes.is_chars() => if s.is_empty() { return Ordering::Equal; } else { return Ordering::Less; }, (HeapCellValue::Addr(Addr::HeapCell(hc1)), HeapCellValue::Addr(Addr::HeapCell(hc2))) => if hc1 != hc2 { return hc1.cmp(&hc2); }, (HeapCellValue::Addr(Addr::HeapCell(_)), _) => return Ordering::Less, (HeapCellValue::Addr(Addr::StackCell(fr1, sc1)), HeapCellValue::Addr(Addr::StackCell(fr2, sc2))) => if fr1 > fr2 { return Ordering::Greater; } else if fr1 < fr2 || sc1 < sc2 { return Ordering::Less; } else if sc1 > sc2 { return Ordering::Greater; }, (HeapCellValue::Addr(Addr::StackCell(..)), HeapCellValue::Addr(Addr::HeapCell(_))) => return Ordering::Greater, (HeapCellValue::Addr(Addr::StackCell(..)), _) => return Ordering::Less, (HeapCellValue::Addr(Addr::Con(Constant::Number(..))), HeapCellValue::Addr(Addr::HeapCell(_))) => return Ordering::Greater, (HeapCellValue::Addr(Addr::Con(Constant::Number(..))), HeapCellValue::Addr(Addr::StackCell(..))) => return Ordering::Greater, (HeapCellValue::Addr(Addr::Con(Constant::Number(n1))), HeapCellValue::Addr(Addr::Con(Constant::Number(n2)))) => if n1 != n2 { return n1.cmp(&n2); }, (HeapCellValue::Addr(Addr::Con(Constant::Number(_))), _) => return Ordering::Less, (HeapCellValue::Addr(Addr::Con(Constant::String(..))), HeapCellValue::Addr(Addr::HeapCell(_))) => return Ordering::Greater, (HeapCellValue::Addr(Addr::Con(Constant::String(..))), HeapCellValue::Addr(Addr::StackCell(..))) => return Ordering::Greater, (HeapCellValue::Addr(Addr::Con(Constant::String(_))), HeapCellValue::Addr(Addr::Con(Constant::Number(_)))) => return Ordering::Greater, (HeapCellValue::Addr(Addr::Con(Constant::String(s1))), HeapCellValue::Addr(Addr::Con(Constant::String(s2)))) => return if s1.is_expandable() { if s2.is_expandable() { s1.cmp(&s2) } else { Ordering::Greater } } else { if s2.is_expandable() { Ordering::Less } else { s1.cmp(&s2) } }, (HeapCellValue::Addr(Addr::Con(Constant::String(_))), _) => return Ordering::Less, (HeapCellValue::Addr(Addr::Con(Constant::Atom(..))), HeapCellValue::Addr(Addr::HeapCell(_))) => return Ordering::Greater, (HeapCellValue::Addr(Addr::Con(Constant::Atom(..))), HeapCellValue::Addr(Addr::StackCell(..))) => return Ordering::Greater, (HeapCellValue::Addr(Addr::Con(Constant::Atom(_))), HeapCellValue::Addr(Addr::Con(Constant::Number(_)))) => return Ordering::Greater, (HeapCellValue::Addr(Addr::Con(Constant::Atom(_))), HeapCellValue::Addr(Addr::Con(Constant::String(_)))) => return Ordering::Greater, (HeapCellValue::Addr(Addr::Con(Constant::Atom(s1))), HeapCellValue::Addr(Addr::Con(Constant::Atom(s2)))) => if s1 != s2 { return s1.cmp(&s2); }, (HeapCellValue::Addr(Addr::Con(Constant::Atom(_))), _) => return Ordering::Less, (HeapCellValue::NamedStr(ar1, n1, _), HeapCellValue::NamedStr(ar2, n2, _)) => if ar1 < ar2 { return Ordering::Less; } else if ar1 > ar2 { return Ordering::Greater; } else if n1 != n2 { return n1.cmp(&n2); }, (HeapCellValue::Addr(Addr::Lis(_)), HeapCellValue::Addr(Addr::Lis(_))) => continue, (HeapCellValue::Addr(Addr::Lis(_)), HeapCellValue::NamedStr(ar, n, _)) | (HeapCellValue::NamedStr(ar, n, _), HeapCellValue::Addr(Addr::Lis(_))) => if ar == 2 && n.as_str() == "." { continue; } else if ar < 2 { return Ordering::Greater; } else if ar > 2 { return Ordering::Less; } else { return n.as_str().cmp("."); }, (HeapCellValue::NamedStr(..), _) => return Ordering::Greater, (HeapCellValue::Addr(Addr::Lis(_)), _) => return Ordering::Greater, _ => {} } }; Ordering::Equal } pub(super) fn reset_block(&mut self, addr: Addr) { match self.store(addr) { Addr::Con(Constant::Usize(b)) => self.block = b, _ => self.fail = true }; } pub(super) fn execute_inlined(&mut self, inlined: &InlinedClauseType) { match inlined { &InlinedClauseType::CompareNumber(cmp, ref at_1, ref at_2) => { let n1 = try_or_fail!(self, self.get_number(at_1)); let n2 = try_or_fail!(self, self.get_number(at_2)); self.compare_numbers(cmp, n1, n2); }, &InlinedClauseType::IsAtom(r1) => { let d = self.store(self.deref(self[r1].clone())); match d { Addr::Con(Constant::Atom(_)) | Addr::Con(Constant::Char(_)) => self.p += 1, _ => self.fail = true }; }, &InlinedClauseType::IsAtomic(r1) => { let d = self.store(self.deref(self[r1].clone())); match d { Addr::Con(_) => self.p += 1, _ => self.fail = true }; }, &InlinedClauseType::IsInteger(r1) => { let d = self.store(self.deref(self[r1].clone())); match d { Addr::Con(Constant::Number(Number::Integer(_))) => self.p += 1, _ => self.fail = true }; }, &InlinedClauseType::IsCompound(r1) => { let d = self.store(self.deref(self[r1].clone())); match d { Addr::Str(_) | Addr::Lis(_) => self.p += 1, _ => self.fail = true }; }, &InlinedClauseType::IsFloat(r1) => { let d = self.store(self.deref(self[r1].clone())); match d { Addr::Con(Constant::Number(Number::Float(_))) => self.p += 1, _ => self.fail = true }; }, &InlinedClauseType::IsRational(r1) => { let d = self.store(self.deref(self[r1].clone())); match d { Addr::Con(Constant::Number(Number::Rational(_))) => self.p += 1, _ => self.fail = true }; }, &InlinedClauseType::IsString(r1) => { let d = self.store(self.deref(self[r1].clone())); match d { Addr::Con(Constant::String(_)) => self.p += 1, _ => self.fail = true }; }, &InlinedClauseType::IsNonVar(r1) => { let d = self.store(self.deref(self[r1].clone())); match d { Addr::HeapCell(_) | Addr::StackCell(..) => self.fail = true, _ => self.p += 1 }; }, &InlinedClauseType::IsVar(r1) => { let d = self.store(self.deref(self[r1].clone())); match d { Addr::HeapCell(_) | Addr::StackCell(_,_) => self.p += 1, _ => self.fail = true }; }, &InlinedClauseType::IsPartialString(r1) => { let d = self.store(self.deref(self[r1].clone())); match d { Addr::Con(Constant::String(ref s)) if s.is_expandable() => self.p += 1, _ => self.fail = true }; } } } fn try_functor_unify_components(&mut self, name: Addr, arity: Addr) { let a2 = self[temp_v!(2)].clone(); let a3 = self[temp_v!(3)].clone(); self.unify(a2, name); if !self.fail { self.unify(a3, arity); } } fn try_functor_compound_case(&mut self, name: ClauseName, arity: usize) { let name = Addr::Con(Constant::Atom(name)); let arity = Addr::Con(integer!(arity)); self.try_functor_unify_components(name, arity); } pub(super) fn try_functor(&mut self) -> CallResult { let stub = MachineError::functor_stub(clause_name!("functor"), 3); let a1 = self.store(self.deref(self[temp_v!(1)].clone())); match a1.clone() { Addr::Con(_) => self.try_functor_unify_components(a1, Addr::Con(integer!(0))), Addr::Str(o) => match self.heap[o].clone() { HeapCellValue::NamedStr(arity, name, _) => self.try_functor_compound_case(name, arity), _ => self.fail = true }, Addr::Lis(_) => self.try_functor_compound_case(clause_name!("."), 2), Addr::HeapCell(_) | Addr::StackCell(_, _) => { let name = self.store(self.deref(self[temp_v!(2)].clone())); let arity = self.store(self.deref(self[temp_v!(3)].clone())); if name.is_ref() || arity.is_ref() { // 8.5.1.3 a) & 8.5.1.3 b) return Err(self.error_form(MachineError::instantiation_error(), stub)); } if let Addr::Con(Constant::Number(Number::Integer(arity))) = arity { let arity = match arity.to_isize() { Some(arity) => arity, None => { self.fail = true; return Ok(()); } }; if arity > MAX_ARITY as isize { let rep_err = MachineError::representation_error(RepFlag::MaxArity); // 8.5.1.3 f) return Err(self.error_form(rep_err, stub)); } else if arity < 0 { // 8.5.1.3 g) let dom_err = MachineError::domain_error(DomainError::NotLessThanZero, Addr::Con(integer!(arity))); return Err(self.error_form(dom_err, stub)); } match name { Addr::Con(_) if arity == 0 => self.unify(a1, name), Addr::Con(Constant::Atom(name)) => { let f_a = if name.as_str() == "." && arity == 2 { Addr::Lis(self.heap.h) } else { let h = self.heap.h; self.heap.push(HeapCellValue::NamedStr(arity as usize, name, None)); Addr::Str(h) }; for _ in 0 .. arity { let h = self.heap.h; self.heap.push(HeapCellValue::Addr(Addr::HeapCell(h))); } self.unify(a1, f_a); }, Addr::Con(_) => return Err(self.error_form(MachineError::type_error(ValidType::Atom, name), stub)), // 8.5.1.3 e) _ => return Err(self.error_form(MachineError::type_error(ValidType::Atomic, name), stub)) // 8.5.1.3 c) }; } else if !arity.is_ref() { // 8.5.1.3 d) return Err(self.error_form(MachineError::type_error(ValidType::Integer, arity), stub)); } } }; Ok(()) } pub(super) fn term_dedup(&self, list: &mut Vec) { let mut result = vec![]; for a2 in list.iter().cloned() { if let Some(a1) = result.last().cloned() { if self.compare_term_test(&a1, &a2) == Ordering::Equal { continue; } } result.push(a2); } *list = result; } pub(super) fn to_list>(&mut self, values: Iter) -> usize { let head_addr = self.heap.h; for value in values { let h = self.heap.h; self.heap.push(HeapCellValue::Addr(Addr::Lis(h+1))); self.heap.push(HeapCellValue::Addr(value)); } self.heap.push(HeapCellValue::Addr(Addr::Con(Constant::EmptyList))); head_addr } pub(super) fn try_from_list(&self, r: RegType, caller: MachineStub) -> Result, MachineStub> { let a1 = self.store(self.deref(self[r].clone())); match a1.clone() { Addr::Lis(mut l) => { let mut result = Vec::new(); result.push(self.heap[l].as_addr(l)); l += 1; loop { match self.heap[l].clone() { HeapCellValue::Addr(addr) => match self.store(self.deref(addr)) { Addr::Lis(hcp) => { result.push(self.heap[hcp].as_addr(hcp)); l = hcp + 1; }, Addr::Con(Constant::EmptyList) => break, Addr::HeapCell(_) | Addr::StackCell(..) => return Err(self.error_form(MachineError::instantiation_error(), caller)), _ => return Err(self.error_form(MachineError::type_error(ValidType::List, a1), caller)) }, _ => return Err(self.error_form(MachineError::type_error(ValidType::List, a1), caller)) }; } Ok(result) }, Addr::HeapCell(_) | Addr::StackCell(..) => Err(self.error_form(MachineError::instantiation_error(), caller)), Addr::Con(Constant::EmptyList) => Ok(vec![]), _ => Err(self.error_form(MachineError::type_error(ValidType::List, a1), caller)) } } // see 8.4.4.3 of Draft Technical Corrigendum 2 for an error guide. pub(super) fn project_onto_key(&self, a: Addr) -> Result { let stub = MachineError::functor_stub(clause_name!("keysort"), 2); match self.store(self.deref(a)) { Addr::HeapCell(_) | Addr::StackCell(..) => Err(self.error_form(MachineError::instantiation_error(), stub)), Addr::Str(s) => match self.heap[s].clone() { HeapCellValue::NamedStr(2, ref name, Some(Fixity::In)) if *name == clause_name!("-") => Ok(Addr::HeapCell(s+1)), _ => Err(self.error_form(MachineError::type_error(ValidType::Pair, self.heap[s].as_addr(s)), stub)) }, a => Err(self.error_form(MachineError::type_error(ValidType::Pair, a), stub)) } } pub(super) fn duplicate_term(&mut self) { let old_h = self.heap.h; let a1 = self[temp_v!(1)].clone(); let a2 = self[temp_v!(2)].clone(); // drop the mutable references contained in gadget // once the term has been duplicated. { let mut gadget = DuplicateTerm::new(self); gadget.duplicate_term(a1); } self.unify(Addr::HeapCell(old_h), a2); } // returns true on failure. pub(super) fn structural_eq_test(&self) -> bool { let a1 = self[temp_v!(1)].clone(); let a2 = self[temp_v!(2)].clone(); let mut var_pairs = HashMap::new(); let iter = self.zipped_acyclic_pre_order_iter(a1, a2); for (v1, v2) in iter { match (v1, v2) { (HeapCellValue::Addr(Addr::Lis(l)), HeapCellValue::Addr(Addr::Con(Constant::String(ref s)))) | (HeapCellValue::Addr(Addr::Con(Constant::String(ref s))), HeapCellValue::Addr(Addr::Lis(l))) if self.flags.double_quotes.is_chars() => if s.is_empty() { return true; } else { if let HeapCellValue::Addr(Addr::Con(constant)) = self.heap[l].clone() { if let Some(c) = s.head() { // checks equality on atoms, too. if constant == Constant::Char(c) { continue; } } } return true; }, (HeapCellValue::Addr(Addr::Con(Constant::String(ref s1))), HeapCellValue::Addr(Addr::Con(Constant::String(ref s2)))) => match s1.head() { Some(c1) => if let Some(c2) = s2.head() { if c1 != c2 { return true; } } else { return true; }, None => return !s2.is_empty() }, (HeapCellValue::Addr(Addr::Con(Constant::String(ref s))), HeapCellValue::Addr(Addr::Con(Constant::EmptyList))) | (HeapCellValue::Addr(Addr::Con(Constant::EmptyList)), HeapCellValue::Addr(Addr::Con(Constant::String(ref s)))) if self.flags.double_quotes.is_chars() => if !s.is_empty() { return true; }, (HeapCellValue::NamedStr(ar1, n1, _), HeapCellValue::NamedStr(ar2, n2, _)) => if ar1 != ar2 || n1 != n2 { return true; }, (HeapCellValue::Addr(Addr::Lis(_)), HeapCellValue::Addr(Addr::Lis(_))) => continue, (HeapCellValue::Addr(v1 @ Addr::HeapCell(_)), HeapCellValue::Addr(v2 @ Addr::HeapCell(_))) | (HeapCellValue::Addr(v1 @ Addr::HeapCell(_)), HeapCellValue::Addr(v2 @ Addr::StackCell(..))) | (HeapCellValue::Addr(v1 @ Addr::StackCell(..)), HeapCellValue::Addr(v2 @ Addr::StackCell(..))) | (HeapCellValue::Addr(v1 @ Addr::StackCell(..)), HeapCellValue::Addr(v2 @ Addr::HeapCell(_))) => match (var_pairs.get(&v1).cloned(), var_pairs.get(&v2).cloned()) { (Some(ref v2_p), Some(ref v1_p)) if *v1_p == v1 && *v2_p == v2 => continue, (Some(_), _) | (_, Some(_)) => return true, (None, None) => { var_pairs.insert(v1.clone(), v2.clone()); var_pairs.insert(v2, v1); } }, (HeapCellValue::Addr(a1), HeapCellValue::Addr(a2)) => if a1 != a2 { return true; }, _ => return true } } false } // returns true on failure. pub(super) fn ground_test(&self) -> bool { let a = self.store(self.deref(self[temp_v!(1)].clone())); for v in self.acyclic_pre_order_iter(a) { match v { HeapCellValue::Addr(Addr::HeapCell(..)) => return true, HeapCellValue::Addr(Addr::StackCell(..)) => return true, _ => {} } }; false } pub(super) fn setup_built_in_call(&mut self, ct: BuiltInClauseType) { self.num_of_args = ct.arity(); self.b0 = self.b; self.p = CodePtr::BuiltInClause(ct, self.p.local()); } pub(super) fn allocate(&mut self, num_cells: usize) { let gi = self.next_global_index(); self.p += 1; if self.e + 1 < self.and_stack.len() { let and_gi = self.and_stack[self.e].global_index; let or_gi = self.or_stack.top() .map(|or_fr| or_fr.global_index) .unwrap_or(0); if and_gi > or_gi { let index = self.e + 1; self.and_stack[index].e = self.e; self.and_stack[index].cp = self.cp.clone(); self.and_stack[index].global_index = gi; self.and_stack.resize(index, num_cells); self.e = index; return; } } self.and_stack.push(gi, self.e, self.cp.clone(), num_cells); self.e = self.and_stack.len() - 1; } fn deallocate(&mut self) { let e = self.e; self.cp = self.and_stack[e].cp.clone(); self.e = self.and_stack[e].e; self.p += 1; } fn handle_call_clause<'a>(&mut self, code_dirs: CodeDirs<'a>, call_policy: &mut Box, cut_policy: &mut Box, ct: &ClauseType, arity: usize, lco: bool, use_default_cp: bool) { let mut default_call_policy: Box = Box::new(DefaultCallPolicy {}); let call_policy = if use_default_cp { &mut default_call_policy } else { call_policy }; self.last_call = lco; match ct { &ClauseType::BuiltIn(ref ct) => try_or_fail!(self, call_policy.call_builtin(self, ct, code_dirs)), &ClauseType::CallN => try_or_fail!(self, call_policy.call_n(self, arity, code_dirs)), &ClauseType::Inlined(ref ct) => self.execute_inlined(ct), &ClauseType::Named(ref name, ref idx) | &ClauseType::Op(ref name, _, ref idx) => try_or_fail!(self, call_policy.context_call(self, name.clone(), arity, idx.clone(), code_dirs)), &ClauseType::System(ref ct) => try_or_fail!(self, self.system_call(ct, code_dirs, call_policy, cut_policy)) }; } pub(super) fn execute_ctrl_instr<'a>(&mut self, code_dirs: CodeDirs<'a>, call_policy: &mut Box, cut_policy: &mut Box, instr: &ControlInstruction) { match instr { &ControlInstruction::Allocate(num_cells) => self.allocate(num_cells), &ControlInstruction::CallClause(ref ct, arity, _, lco, use_default_cp) => self.handle_call_clause(code_dirs, call_policy, cut_policy, ct, arity, lco, use_default_cp), &ControlInstruction::Deallocate => self.deallocate(), &ControlInstruction::JmpBy(arity, offset, _, lco) => { if !lco { self.cp.assign_if_local(self.p.clone() + 1); } self.num_of_args = arity; self.b0 = self.b; self.p += offset; }, &ControlInstruction::Proceed => self.p = CodePtr::Local(self.cp.clone()) }; } pub(super) fn execute_indexed_choice_instr(&mut self, instr: &IndexedChoiceInstruction, call_policy: &mut Box) { match instr { &IndexedChoiceInstruction::Try(l) => { let n = self.num_of_args; let gi = self.next_global_index(); self.or_stack.push(gi, self.e, self.cp.clone(), self.b, self.p.clone() + 1, self.tr, self.heap.h, self.b0, self.num_of_args); self.b = self.or_stack.len(); let b = self.b - 1; for i in 1 .. n + 1 { self.or_stack[b][i] = self.registers[i].clone(); } self.hb = self.heap.h; self.p += l; }, &IndexedChoiceInstruction::Retry(l) => try_or_fail!(self, call_policy.retry(self, l)), &IndexedChoiceInstruction::Trust(l) => try_or_fail!(self, call_policy.trust(self, l)) }; } pub(super) fn execute_choice_instr(&mut self, instr: &ChoiceInstruction, call_policy: &mut Box) { match instr { &ChoiceInstruction::TryMeElse(offset) => { let n = self.num_of_args; let gi = self.next_global_index(); self.or_stack.push(gi, self.e, self.cp.clone(), self.b, self.p.clone() + offset, self.tr, self.heap.h, self.b0, self.num_of_args); self.b = self.or_stack.len(); let b = self.b - 1; for i in 1 .. n + 1 { self.or_stack[b][i] = self.registers[i].clone(); } self.hb = self.heap.h; self.p += 1; }, &ChoiceInstruction::DefaultRetryMeElse(offset) => { let mut call_policy = DefaultCallPolicy {}; try_or_fail!(self, call_policy.retry_me_else(self, offset)) }, &ChoiceInstruction::DefaultTrustMe => { let mut call_policy = DefaultCallPolicy {}; try_or_fail!(self, call_policy.trust_me(self)) }, &ChoiceInstruction::RetryMeElse(offset) => try_or_fail!(self, call_policy.retry_me_else(self, offset)), &ChoiceInstruction::TrustMe => try_or_fail!(self, call_policy.trust_me(self)) } } pub(super) fn execute_cut_instr(&mut self, instr: &CutInstruction, cut_policy: &mut Box) { match instr { &CutInstruction::NeckCut => { let b = self.b; let b0 = self.b0; if b > b0 { self.b = b0; self.tidy_trail(); self.or_stack.truncate(self.b); } self.p += 1; }, &CutInstruction::GetLevel(r) => { let b0 = self.b0; self[r] = Addr::Con(Constant::Usize(b0)); self.p += 1; }, &CutInstruction::GetLevelAndUnify(r) => { // let b0 = Addr::Con(Constant::Usize(self.b0)); let b0 = self[perm_v!(1)].clone(); let a = self[r].clone(); self.unify(a, b0); self.p += 1; }, &CutInstruction::Cut(r) => if !cut_policy.cut(self, r) { self.p += 1; } } } pub(super) fn reset(&mut self) { self.hb = 0; self.e = 0; self.b = 0; self.b0 = 0; self.s = 0; self.tr = 0; self.p = CodePtr::default(); self.cp = LocalCodePtr::default(); self.num_of_args = 0; self.fail = false; self.trail.clear(); self.heap.clear(); self.mode = MachineMode::Write; self.and_stack.clear(); self.or_stack.clear(); self.registers = vec![Addr::HeapCell(0); 64]; self.block = 0; self.ball.reset(); } }