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system calls preliminary

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This commit is contained in:
Mark Thom
2018-05-07 22:27:58 -06:00
parent a1bfcf4c9d
commit 1a0f50200f
5 changed files with 52 additions and 187 deletions
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43
src/prolog/ast.rs
View File

@@ -683,6 +683,26 @@ pub struct Rule {
pub clauses: Vec<QueryTerm> pub clauses: Vec<QueryTerm>
} }
#[derive(Clone)]
pub enum SystemClauseType {
SkipMaxList
}
impl SystemClauseType {
pub fn name(&self) -> ClauseName {
match self {
&SystemClauseType::SkipMaxList => clause_name!("$skip_max_list"),
}
}
pub fn from(name: &str, arity: usize) -> Option<SystemClauseType> {
match (name, arity) {
("$skip_max_list", 4) => Some(SystemClauseType::SkipMaxList),
_ => None
}
}
}
#[derive(Clone)] #[derive(Clone)]
pub enum ClauseType { pub enum ClauseType {
AcyclicTerm, AcyclicTerm,
@@ -705,8 +725,8 @@ pub enum ClauseType {
Op(ClauseName, Fixity, CodeIndex), Op(ClauseName, Fixity, CodeIndex),
Named(ClauseName, CodeIndex), Named(ClauseName, CodeIndex),
SetupCallCleanup, SetupCallCleanup,
SkipMaxList,
Sort, Sort,
System(SystemClauseType),
Throw, Throw,
} }
@@ -788,14 +808,14 @@ impl ClauseType {
pub fn name(&self) -> ClauseName { pub fn name(&self) -> ClauseName {
match self { match self {
&ClauseType::AcyclicTerm => clause_name!("acyclic_term"), &ClauseType::AcyclicTerm => clause_name!("$acyclic_term"),
&ClauseType::Arg => clause_name!("arg"), &ClauseType::Arg => clause_name!("arg"),
&ClauseType::CallN => clause_name!("call"), &ClauseType::CallN => clause_name!("call"),
&ClauseType::CallWithInferenceLimit => clause_name!("call_with_inference_limit"), &ClauseType::CallWithInferenceLimit => clause_name!("call_with_inference_limit"),
&ClauseType::Catch => clause_name!("catch"), &ClauseType::Catch => clause_name!("catch"),
&ClauseType::Compare => clause_name!("compare"), &ClauseType::Compare => clause_name!("compare"),
&ClauseType::CompareTerm(qt) => clause_name!(qt.name()), &ClauseType::CompareTerm(qt) => clause_name!(qt.name()),
&ClauseType::CyclicTerm => clause_name!("cyclic_term"), &ClauseType::CyclicTerm => clause_name!("$cyclic_term"),
&ClauseType::Display => clause_name!("display"), &ClauseType::Display => clause_name!("display"),
&ClauseType::DuplicateTerm => clause_name!("duplicate_term"), &ClauseType::DuplicateTerm => clause_name!("duplicate_term"),
&ClauseType::Eq => clause_name!("=="), &ClauseType::Eq => clause_name!("=="),
@@ -803,26 +823,26 @@ impl ClauseType {
&ClauseType::Ground => clause_name!("ground"), &ClauseType::Ground => clause_name!("ground"),
&ClauseType::Inlined(inlined) => clause_name!(inlined.name()), &ClauseType::Inlined(inlined) => clause_name!(inlined.name()),
&ClauseType::Is => clause_name!("is"), &ClauseType::Is => clause_name!("is"),
&ClauseType::KeySort => clause_name!("keysort"), &ClauseType::KeySort => clause_name!("$keysort"),
&ClauseType::NotEq => clause_name!("\\=="), &ClauseType::NotEq => clause_name!("\\=="),
&ClauseType::Op(ref name, ..) => name.clone(), &ClauseType::Op(ref name, ..) => name.clone(),
&ClauseType::Named(ref name, ..) => name.clone(), &ClauseType::Named(ref name, ..) => name.clone(),
&ClauseType::SetupCallCleanup => clause_name!("setup_call_cleanup"), &ClauseType::SetupCallCleanup => clause_name!("setup_call_cleanup"),
&ClauseType::SkipMaxList => clause_name!("$skip_max_list"), &ClauseType::System(ref system) => system.name(),
&ClauseType::Sort => clause_name!("sort"), &ClauseType::Sort => clause_name!("$sort"),
&ClauseType::Throw => clause_name!("throw") &ClauseType::Throw => clause_name!("throw")
} }
} }
pub fn from(name: ClauseName, arity: usize, fixity: Option<Fixity>) -> Self { pub fn from(name: ClauseName, arity: usize, fixity: Option<Fixity>) -> Self {
match (name.as_str(), arity) { match (name.as_str(), arity) {
("acyclic_term", 1) => ClauseType::AcyclicTerm, ("$acyclic_term", 1) => ClauseType::AcyclicTerm,
("arg", 3) => ClauseType::Arg, ("arg", 3) => ClauseType::Arg,
("call", _) => ClauseType::CallN, ("call", _) => ClauseType::CallN,
("call_with_inference_limit", 3) => ClauseType::CallWithInferenceLimit, ("call_with_inference_limit", 3) => ClauseType::CallWithInferenceLimit,
("catch", 3) => ClauseType::Catch, ("catch", 3) => ClauseType::Catch,
("compare", 3) => ClauseType::Compare, ("compare", 3) => ClauseType::Compare,
("cyclic_term", 1) => ClauseType::CyclicTerm, ("$cyclic_term", 1) => ClauseType::CyclicTerm,
("@>", 2) => ClauseType::CompareTerm(CompareTermQT::GreaterThan), ("@>", 2) => ClauseType::CompareTerm(CompareTermQT::GreaterThan),
("@<", 2) => ClauseType::CompareTerm(CompareTermQT::LessThan), ("@<", 2) => ClauseType::CompareTerm(CompareTermQT::LessThan),
("@>=", 2) => ClauseType::CompareTerm(CompareTermQT::GreaterThanOrEqual), ("@>=", 2) => ClauseType::CompareTerm(CompareTermQT::GreaterThanOrEqual),
@@ -835,11 +855,10 @@ impl ClauseType {
("functor", 3) => ClauseType::Functor, ("functor", 3) => ClauseType::Functor,
("ground", 1) => ClauseType::Ground, ("ground", 1) => ClauseType::Ground,
("is", 2) => ClauseType::Is, ("is", 2) => ClauseType::Is,
("keysort", 2) => ClauseType::KeySort, ("$keysort", 2) => ClauseType::KeySort,
("\\==", 2) => ClauseType::NotEq, ("\\==", 2) => ClauseType::NotEq,
("setup_call_cleanup", 3) => ClauseType::SetupCallCleanup, ("setup_call_cleanup", 3) => ClauseType::SetupCallCleanup,
("$skip_max_list", 4) => ClauseType::SkipMaxList, ("$sort", 2) => ClauseType::Sort,
("sort", 2) => ClauseType::Sort,
("throw", 1) => ClauseType::Throw, ("throw", 1) => ClauseType::Throw,
_ => if let Some(fixity) = fixity { _ => if let Some(fixity) = fixity {
ClauseType::Op(name, fixity, CodeIndex::default()) ClauseType::Op(name, fixity, CodeIndex::default())

2
src/prolog/builtins.rs
View File

@@ -736,7 +736,6 @@ fn get_builtins() -> Code {
keysort_execute!(), // keysort/2, 484. keysort_execute!(), // keysort/2, 484.
acyclic_term_execute!(), // acyclic_term/1, 485. acyclic_term_execute!(), // acyclic_term/1, 485.
cyclic_term_execute!(), // cyclic_term/1, 486. cyclic_term_execute!(), // cyclic_term/1, 486.
skip_max_list_execute!() // '$skip_max_list', 487.
] ]
} }
@@ -856,7 +855,6 @@ pub fn build_code_and_op_dirs() -> (CodeDir, OpDir)
code_dir.insert((clause_name!("keysort"), 2), CodeIndex::from((484, builtin.clone()))); code_dir.insert((clause_name!("keysort"), 2), CodeIndex::from((484, builtin.clone())));
code_dir.insert((clause_name!("acyclic_term"), 1), CodeIndex::from((485, builtin.clone()))); code_dir.insert((clause_name!("acyclic_term"), 1), CodeIndex::from((485, builtin.clone())));
code_dir.insert((clause_name!("cyclic_term"), 1), CodeIndex::from((486, builtin.clone()))); code_dir.insert((clause_name!("cyclic_term"), 1), CodeIndex::from((486, builtin.clone())));
code_dir.insert((clause_name!("$skip_max_list"), 4), CodeIndex::from((487, builtin.clone())));
(code_dir, op_dir) (code_dir, op_dir)
} }

24
src/prolog/machine/machine_state.rs
View File

@@ -17,14 +17,14 @@ use std::rc::Rc;
pub(super) struct Ball { pub(super) struct Ball {
pub(super) boundary: usize, // ball.0 pub(super) boundary: usize, // ball.0
pub(super) stub: MachineStub, // ball.1 pub(super) stub: MachineStub, // ball.1
} }
impl Ball { impl Ball {
pub(super) fn new() -> Self { pub(super) fn new() -> Self {
Ball { boundary: 0, stub: MachineStub::new() } Ball { boundary: 0, stub: MachineStub::new() }
} }
pub(super) fn reset(&mut self) { pub(super) fn reset(&mut self) {
self.boundary = 0; self.boundary = 0;
self.stub.clear(); self.stub.clear();
@@ -502,10 +502,10 @@ pub(crate) trait CallPolicy: Any {
}, },
&ClauseType::Sort => { &ClauseType::Sort => {
machine_st.check_sort_errors()?; machine_st.check_sort_errors()?;
let stub = machine_st.functor_stub(clause_name!("sort"), 2); let stub = machine_st.functor_stub(clause_name!("sort"), 2);
let mut list = machine_st.try_from_list(temp_v!(1), stub)?; let mut list = machine_st.try_from_list(temp_v!(1), stub)?;
list.sort_unstable_by(|a1, a2| machine_st.compare_term_test(a1, a2)); list.sort_unstable_by(|a1, a2| machine_st.compare_term_test(a1, a2));
machine_st.term_dedup(&mut list); machine_st.term_dedup(&mut list);
@@ -518,11 +518,11 @@ pub(crate) trait CallPolicy: Any {
}, },
&ClauseType::KeySort => { &ClauseType::KeySort => {
machine_st.check_keysort_errors()?; machine_st.check_keysort_errors()?;
let stub = machine_st.functor_stub(clause_name!("keysort"), 2); let stub = machine_st.functor_stub(clause_name!("keysort"), 2);
let mut list = machine_st.try_from_list(temp_v!(1), stub)?; let mut list = machine_st.try_from_list(temp_v!(1), stub)?;
let mut key_pairs = Vec::new(); let mut key_pairs = Vec::new();
for val in list { for val in list {
let key = machine_st.project_onto_key(val.clone())?; let key = machine_st.project_onto_key(val.clone())?;
key_pairs.push((key, val.clone())); key_pairs.push((key, val.clone()));
@@ -569,11 +569,9 @@ pub(crate) trait CallPolicy: Any {
machine_st.execute_inlined(inlined, &vec![temp_v!(1), temp_v!(2)]); machine_st.execute_inlined(inlined, &vec![temp_v!(1), temp_v!(2)]);
Ok(()) Ok(())
}, },
&ClauseType::SkipMaxList => { &ClauseType::System(ref system) => {
machine_st.skip_max_list()?; machine_st.execute_system(system)?;
machine_st.p += 1; return_from_clause!(lco, machine_st)
Ok(())
} }
} }
} }

169
src/prolog/machine/machine_state_impl.rs
View File

@@ -100,12 +100,12 @@ impl MachineState {
where Fmt: HCValueFormatter, Outputter: HCValueOutputter where Fmt: HCValueFormatter, Outputter: HCValueOutputter
{ {
let orig_len = output.len(); let orig_len = output.len();
output.begin_new_var(); output.begin_new_var();
output.append(var.as_str()); output.append(var.as_str());
output.append(" = "); output.append(" = ");
let printer = HCPrinter::from_heap_locs(&self, fmt, output, var_dir); let printer = HCPrinter::from_heap_locs(&self, fmt, output, var_dir);
let mut output = printer.print(addr); let mut output = printer.print(addr);
@@ -125,7 +125,7 @@ impl MachineState {
let printer = HCPrinter::from_heap_locs_as_seen(&self, fmt, output, var_dir); let printer = HCPrinter::from_heap_locs_as_seen(&self, fmt, output, var_dir);
printer.print(addr) printer.print(addr)
} }
pub(super) pub(super)
fn print_term<Fmt, Outputter>(&self, addr: Addr, fmt: Fmt, output: Outputter) -> Outputter fn print_term<Fmt, Outputter>(&self, addr: Addr, fmt: Fmt, output: Outputter) -> Outputter
where Fmt: HCValueFormatter, Outputter: HCValueOutputter where Fmt: HCValueFormatter, Outputter: HCValueOutputter
@@ -1106,10 +1106,10 @@ impl MachineState {
self.heap.h - self.ball.boundary self.heap.h - self.ball.boundary
} }
} }
pub(super) fn copy_and_align_ball_to_heap(&mut self) -> usize { pub(super) fn copy_and_align_ball_to_heap(&mut self) -> usize {
let diff = self.heap_ball_boundary_diff(); let diff = self.heap_ball_boundary_diff();
for heap_value in self.ball.stub.iter().cloned() { for heap_value in self.ball.stub.iter().cloned() {
self.heap.push(match heap_value { self.heap.push(match heap_value {
HeapCellValue::Addr(addr) => HeapCellValue::Addr(addr - diff), HeapCellValue::Addr(addr) => HeapCellValue::Addr(addr - diff),
@@ -1186,7 +1186,7 @@ impl MachineState {
self.p += 1; self.p += 1;
} }
pub(super) fn compare_term(&mut self, qt: CompareTermQT) { pub(super) fn compare_term(&mut self, qt: CompareTermQT) {
let a1 = self[temp_v!(1)].clone(); let a1 = self[temp_v!(1)].clone();
let a2 = self[temp_v!(2)].clone(); let a2 = self[temp_v!(2)].clone();
@@ -1441,7 +1441,7 @@ impl MachineState {
try_or_fail!(self, call_policy.trust_me(self)); try_or_fail!(self, call_policy.trust_me(self));
}, },
&BuiltInInstruction::EraseBall => { &BuiltInInstruction::EraseBall => {
self.ball.reset(); self.ball.reset();
self.p += 1; self.p += 1;
}, },
&BuiltInInstruction::GetArg(lco) => &BuiltInInstruction::GetArg(lco) =>
@@ -1621,7 +1621,7 @@ impl MachineState {
let mut duplicator = DuplicateBallTerm::new(self); let mut duplicator = DuplicateBallTerm::new(self);
duplicator.duplicate_term(addr); duplicator.duplicate_term(addr);
}; };
self.p += 1; self.p += 1;
}, },
&BuiltInInstruction::SetCutPoint(r) => &BuiltInInstruction::SetCutPoint(r) =>
@@ -1841,157 +1841,6 @@ impl MachineState {
} }
} }
pub(super) fn detect_cycles_with_max(&self, max_steps: usize, addr: Addr) -> CycleSearchResult
{
let addr = self.store(self.deref(addr));
let mut hare = match addr {
Addr::Lis(offset) if max_steps > 0 => offset + 1,
Addr::Lis(offset) => return CycleSearchResult::UntouchedList(offset),
Addr::Con(Constant::EmptyList) => return CycleSearchResult::EmptyList,
_ => return CycleSearchResult::NotList
};
// use Brent's algorithm to detect cycles.
let mut tortoise = hare;
let mut power = 2;
let mut steps = 1;
loop {
if steps == max_steps {
return CycleSearchResult::PartialList(steps, hare);
}
match self.heap[hare].clone() {
HeapCellValue::Addr(Addr::Lis(l)) => {
hare = l + 1;
steps += 1;
if tortoise == hare {
return CycleSearchResult::NotList;
} else if steps == power {
tortoise = hare;
power <<= 1;
}
},
HeapCellValue::NamedStr(..) =>
return CycleSearchResult::NotList,
HeapCellValue::Addr(addr) =>
match self.store(self.deref(addr)) {
Addr::Con(Constant::EmptyList) =>
return CycleSearchResult::ProperList(steps),
Addr::HeapCell(_) | Addr::StackCell(..) =>
return CycleSearchResult::PartialList(steps, hare),
_ =>
return CycleSearchResult::NotList
}
}
}
}
pub(super) fn detect_cycles(&self, addr: Addr) -> CycleSearchResult
{
let addr = self.store(self.deref(addr));
let mut hare = match addr {
Addr::Lis(offset) => offset + 1,
Addr::Con(Constant::EmptyList) => return CycleSearchResult::EmptyList,
_ => return CycleSearchResult::NotList
};
// use Brent's algorithm to detect cycles.
let mut tortoise = hare;
let mut power = 2;
let mut steps = 1;
loop {
match self.heap[hare].clone() {
HeapCellValue::Addr(Addr::Lis(l)) => {
hare = l + 1;
steps += 1;
if tortoise == hare {
return CycleSearchResult::NotList;
} else if steps == power {
tortoise = hare;
power <<= 1;
}
},
HeapCellValue::NamedStr(..) =>
return CycleSearchResult::NotList,
HeapCellValue::Addr(addr) =>
match self.store(self.deref(addr)) {
Addr::Con(Constant::EmptyList) =>
return CycleSearchResult::ProperList(steps),
Addr::HeapCell(_) | Addr::StackCell(..) =>
return CycleSearchResult::PartialList(steps, hare),
_ =>
return CycleSearchResult::NotList
}
}
}
}
fn finalize_skip_max_list(&mut self, n: usize, addr: Addr) {
let target_n = self[temp_v!(1)].clone();
self.unify(Addr::Con(integer!(n)), target_n);
if !self.fail {
let xs = self[temp_v!(4)].clone();
self.unify(addr, xs);
}
}
pub(super) fn skip_max_list(&mut self) -> Result<(), MachineError> {
let max_steps = self.arith_eval_by_metacall(temp_v!(2))?;
match max_steps {
Number::Integer(ref max_steps)
if max_steps.to_isize().map(|i| i >= -1).unwrap_or(false) => {
let n = self.store(self.deref(self[temp_v!(1)].clone()));
match n {
Addr::Con(Constant::Number(Number::Integer(ref n))) if n.is_zero() => {
let xs0 = self[temp_v!(3)].clone();
let xs = self[temp_v!(4)].clone();
self.unify(xs0, xs);
},
_ => {
let search_result = if let Some(max_steps) = max_steps.to_isize() {
if max_steps == -1 {
self.detect_cycles(self[temp_v!(3)].clone())
} else {
self.detect_cycles_with_max(max_steps as usize,
self[temp_v!(3)].clone())
}
} else {
self.detect_cycles(self[temp_v!(3)].clone())
};
match search_result {
CycleSearchResult::UntouchedList(l) =>
self.finalize_skip_max_list(0, Addr::Lis(l)),
CycleSearchResult::EmptyList =>
self.finalize_skip_max_list(0, Addr::Con(Constant::EmptyList)),
CycleSearchResult::PartialList(n, hc) =>
self.finalize_skip_max_list(n, Addr::HeapCell(hc)),
CycleSearchResult::ProperList(n) =>
self.finalize_skip_max_list(n, Addr::Con(Constant::EmptyList)),
CycleSearchResult::NotList => {
let xs0 = self[temp_v!(3)].clone();
self.finalize_skip_max_list(0, xs0);
}
}
}
}
},
_ => self.fail = true
};
Ok(())
}
pub(super) fn duplicate_term(&mut self) { pub(super) fn duplicate_term(&mut self) {
let old_h = self.heap.h; let old_h = self.heap.h;
@@ -2330,7 +2179,7 @@ impl MachineState {
self.or_stack.clear(); self.or_stack.clear();
self.registers = vec![Addr::HeapCell(0); 64]; self.registers = vec![Addr::HeapCell(0); 64];
self.block = 0; self.block = 0;
self.ball.reset(); self.ball.reset();
} }
} }

1
src/prolog/machine/mod.rs
View File

@@ -7,6 +7,7 @@ mod machine_errors;
pub(super) mod machine_state; pub(super) mod machine_state;
#[macro_use] #[macro_use]
mod machine_state_impl; mod machine_state_impl;
mod system_calls;
use prolog::machine::machine_state::*; use prolog::machine::machine_state::*;