rishi/scryer-prolog
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introduce a better binding scheme for attributed variables

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This commit is contained in:
Mark Thom
2019-02-03 15:16:30 -07:00
parent f51405bc04
commit 3cfbbb23a3
9 changed files with 122 additions and 105 deletions
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26
src/prolog/instructions.rs
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@@ -717,7 +717,7 @@ pub type CodeDeque = VecDeque<Line>;
#[derive(Clone, PartialEq, Eq, Hash)]
pub enum Addr {
AttrVar(usize, usize), // the location of the AttrVal in the heap, the location of the attribute list.
AttrVar(usize),
Con(Constant),
Lis(usize),
HeapCell(usize),
@@ -737,7 +737,8 @@ impl PartialOrd<Ref> for Addr {
match self {
&Addr::StackCell(fr, sc) =>
match *r {
Ref::HeapCell(_) => Some(Ordering::Greater),
Ref::AttrVar(_) | Ref::HeapCell(_) =>
Some(Ordering::Greater),
Ref::StackCell(fr1, sc1) =>
if fr1 < fr || (fr1 == fr && sc1 < sc) {
Some(Ordering::Greater)
@@ -747,10 +748,10 @@ impl PartialOrd<Ref> for Addr {
Some(Ordering::Less)
}
},
&Addr::HeapCell(h) | &Addr::AttrVar(h, _) =>
&Addr::HeapCell(h) | &Addr::AttrVar(h) =>
match r {
&Ref::StackCell(..) => Some(Ordering::Less),
&Ref::HeapCell(h1) => h.partial_cmp(&h1)
&Ref::AttrVar(h1) | &Ref::HeapCell(h1) => h.partial_cmp(&h1)
},
_ => None
}
@@ -760,14 +761,14 @@ impl PartialOrd<Ref> for Addr {
impl Addr {
pub fn is_ref(&self) -> bool {
match self {
&Addr::AttrVar(..) | &Addr::HeapCell(_) | &Addr::StackCell(_, _) => true,
&Addr::AttrVar(_) | &Addr::HeapCell(_) | &Addr::StackCell(_, _) => true,
_ => false
}
}
pub fn as_var(&self) -> Option<Ref> {
match self {
&Addr::AttrVar(h, _) => Some(Ref::HeapCell(h)),
&Addr::AttrVar(h) => Some(Ref::AttrVar(h)),
&Addr::HeapCell(h) => Some(Ref::HeapCell(h)),
&Addr::StackCell(fr, sc) => Some(Ref::StackCell(fr, sc)),
_ => None
@@ -788,6 +789,7 @@ impl Add<usize> for Addr {
fn add(self, rhs: usize) -> Self::Output {
match self {
Addr::Lis(a) => Addr::Lis(a + rhs),
Addr::AttrVar(h) => Addr::AttrVar(h + rhs),
Addr::HeapCell(h) => Addr::HeapCell(h + rhs),
Addr::Str(s) => Addr::Str(s + rhs),
_ => self
@@ -801,6 +803,7 @@ impl Sub<usize> for Addr {
fn sub(self, rhs: usize) -> Self::Output {
match self {
Addr::Lis(a) => Addr::Lis(a - rhs),
Addr::AttrVar(h) => Addr::AttrVar(h - rhs),
Addr::HeapCell(h) => Addr::HeapCell(h - rhs),
Addr::Str(s) => Addr::Str(s - rhs),
_ => self
@@ -811,6 +814,7 @@ impl Sub<usize> for Addr {
impl From<Ref> for Addr {
fn from(r: Ref) -> Self {
match r {
Ref::AttrVar(h) => Addr::AttrVar(h),
Ref::HeapCell(h) => Addr::HeapCell(h),
Ref::StackCell(fr, sc) => Addr::StackCell(fr, sc)
}
@@ -819,6 +823,7 @@ impl From<Ref> for Addr {
#[derive(Clone, Copy, Hash, Eq, PartialEq)]
pub enum Ref {
AttrVar(usize),
HeapCell(usize),
StackCell(usize, usize)
}
@@ -826,6 +831,7 @@ pub enum Ref {
impl Ref {
pub fn as_addr(self) -> Addr {
match self {
Ref::AttrVar(h) => Addr::AttrVar(h),
Ref::HeapCell(h) => Addr::HeapCell(h),
Ref::StackCell(fr, sc) => Addr::StackCell(fr, sc)
}
@@ -834,17 +840,13 @@ impl Ref {
#[derive(Clone)]
pub enum TrailRef {
HeapCell(usize),
StackCell(usize, usize),
Ref(Ref),
AttrVarLink(usize, Addr)
}
impl From<Ref> for TrailRef {
fn from(r: Ref) -> Self {
match r {
Ref::HeapCell(h) => TrailRef::HeapCell(h),
Ref::StackCell(fr, sc) => TrailRef::StackCell(fr, sc)
}
TrailRef::Ref(r)
}
}