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Merge branch 'master' of http://github.com/mthom/rusty-wam into develop

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This commit is contained in:
Mark Thom
2018-05-01 20:36:27 -06:00
parent e38bf58e6c d51c950b77
commit b23f17678c
5 changed files with 32 additions and 37 deletions
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9
src/prolog/ast.rs
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@@ -537,7 +537,7 @@ impl fmt::Display for Constant {
&Constant::Atom(ref atom) =>
write!(f, "{}", atom),
&Constant::Char(c) =>
write!(f, "{}", c as u8),
write!(f, "'{}'", c as u8),
&Constant::EmptyList =>
write!(f, "[]"),
&Constant::Number(ref n) =>
@@ -1360,13 +1360,6 @@ impl Addr {
_ => true
}
}
pub fn is_empty_list(&self) -> bool {
match self {
&Addr::Con(Constant::EmptyList) => true,
_ => false
}
}
}
impl From<Ref> for Addr {

7
src/prolog/builtins.rs
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@@ -644,6 +644,7 @@ fn get_builtins() -> Code {
keysort_execute!(), // keysort/2, 484.
acyclic_term_execute!(), // acyclic_term/1, 485.
cyclic_term_execute!(), // cyclic_term/1, 486.
skip_max_list_execute!() // '$skip_max_list', 487.
]
}
@@ -763,7 +764,8 @@ pub fn build_code_and_op_dirs() -> (CodeDir, OpDir)
code_dir.insert((clause_name!("keysort"), 2), CodeIndex::from((484, builtin.clone())));
code_dir.insert((clause_name!("acyclic_term"), 1), CodeIndex::from((485, builtin.clone())));
code_dir.insert((clause_name!("cyclic_term"), 1), CodeIndex::from((486, builtin.clone())));
code_dir.insert((clause_name!("$skip_max_list"), 4), CodeIndex::from((487, builtin.clone())));
(code_dir, op_dir)
}
@@ -826,7 +828,8 @@ pub fn builtin_module() -> Module
(clause_name!("sort"), 2),
(clause_name!("keysort"), 2),
(clause_name!("acyclic_term"), 1),
(clause_name!("cyclic_term"), 1)]);
(clause_name!("cyclic_term"), 1),
(clause_name!("$skip_max_list"), 4)]);
for arity in 0 .. 63 {
module_decl.exports.push((clause_name!("call"), arity));

43
src/prolog/machine/machine_state_impl.rs
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@@ -29,9 +29,10 @@ macro_rules! try_or_fail {
// used by '$skip_max_list'.
enum CycleSearchResult {
EmptyList,
NotList,
PartialOrProperList(usize, usize), // returns the list length (up to max), and an offset into the heap.
UntouchedList(usize) // return the offset of an uniterated Addr::Lis(offset).
NotList,
PartialList(usize, usize), // the list length (up to max), and an offset into the heap.
ProperList(usize), // the list length.
UntouchedList(usize) // the address of an uniterated Addr::Lis(address).
}
impl MachineState {
@@ -1686,8 +1687,7 @@ impl MachineState {
// detect cycles.
match self.detect_cycles(usize::max_value(), a1.clone()) {
CycleSearchResult::PartialOrProperList(_, h)
if self.store(self.deref(self.heap[h].as_addr(h))).is_empty_list() => {},
CycleSearchResult::ProperList(_) => {},
_ => return Err(functor!("type_error", 2, [heap_atom!("list"), HeapCellValue::Addr(a1)]))
};
@@ -1752,7 +1752,7 @@ impl MachineState {
loop {
if steps == max_steps {
return CycleSearchResult::PartialOrProperList(steps, hare);
return CycleSearchResult::PartialList(steps, hare);
}
match self.heap[hare].clone() {
@@ -1768,13 +1768,8 @@ impl MachineState {
}
},
HeapCellValue::Addr(Addr::Con(Constant::EmptyList)) =>
return CycleSearchResult::PartialOrProperList(steps, hare),
HeapCellValue::Addr(Addr::HeapCell(hc)) if hc == hare =>
return CycleSearchResult::PartialOrProperList(steps, hare),
HeapCellValue::Addr(ref sc @ Addr::StackCell(..))
if *sc == self.store(self.deref(sc.clone())) =>
return CycleSearchResult::PartialOrProperList(steps, hare),
_ => return CycleSearchResult::NotList
return CycleSearchResult::ProperList(steps),
_ => return CycleSearchResult::PartialList(steps, hare)
}
}
}
@@ -1788,17 +1783,7 @@ impl MachineState {
self.unify(addr, xs);
}
}
/*
'$skip_max_list'(N, Max, Xs0, Xs):
valid modes: Max is always +Max (a non-negative integer), Xs, Xs0 and N are all ?_.
Modes | Conditions for success
======================================================================================
?N, -Xs0 : N = 0, Xs = Xs0.
?N, +Xs0 : Xs0 is a proper or partial list, Xs0 = [X1, X2, ..., XN | Xs], N = Max,
if |Xs0| >= Max, or, Xs = [] and N = |Xs0|.
*/
pub(super) fn skip_max_list(&mut self) {
let max = self.store(self.deref(self[temp_v!(2)].clone()));
@@ -1822,10 +1807,14 @@ impl MachineState {
self.finalize_skip_max_list(0, Addr::Lis(l)),
CycleSearchResult::EmptyList =>
self.finalize_skip_max_list(0, Addr::Con(Constant::EmptyList)),
CycleSearchResult::PartialOrProperList(n, hc) =>
CycleSearchResult::PartialList(n, hc) =>
self.finalize_skip_max_list(n, Addr::HeapCell(hc)),
CycleSearchResult::NotList =>
self.fail = true
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);
}
}
}
}

6
src/prolog/macros.rs
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@@ -763,6 +763,12 @@ macro_rules! cyclic_term_execute {
)
}
macro_rules! skip_max_list_execute {
() => (
Line::Control(ControlInstruction::CallClause(ClauseType::SkipMaxList, 4, 0, true))
)
}
macro_rules! return_from_clause {
($lco:expr, $machine_st:expr) => {{
if $lco {

4
src/tests.rs
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@@ -1644,4 +1644,8 @@ fn test_queries_on_skip_max_list() {
assert_prolog_failure!(&mut wam, "?- Xs = [a,b|Xs], '$skip_max_list'(3, 5, X, Xs0).");
assert_prolog_failure!(&mut wam, "?- X = [a,b|Y], Y = [c,d|X], '$skip_max_list'(4, 5, X, Xs0).");
assert_prolog_failure!(&mut wam, "?- X = [a,b|Y], Y = [c,d|X], '$skip_max_list'(4, 3, X, Xs0).");
// tests on non lists.
assert_prolog_success!(&mut wam, "?- '$skip_max_list'(N, 9, non_list, Xs).",
[["Xs = non_list", "N = 0"]]);
}