Introduce LitKind to factor out common enum nodes

2 files changed, 50 insertions, 57 deletions

diff --git a/dhall/src/semantics/nze/normalize.rs b/dhall/src/semantics/nze/normalize.rs
index 03b91a5..4111190 100644
--- a/dhall/src/semantics/nze/normalize.rs
+++ b/dhall/src/semantics/nze/normalize.rs
@@ -5,7 +5,9 @@ use crate::semantics::NzEnv;
 use crate::semantics::{
     Binder, BuiltinClosure, Closure, Hir, HirKind, TextLit, Value, ValueKind,
 };
-use crate::syntax::{BinOp, Builtin, ExprKind, InterpolatedTextContents};
+use crate::syntax::{
+    BinOp, Builtin, ExprKind, InterpolatedTextContents, LitKind,
+};
 
 pub(crate) fn apply_any(f: Value, a: Value) -> ValueKind {
     match f.kind() {
@@ -98,40 +100,44 @@ fn apply_binop<'a>(o: BinOp, x: &'a Value, y: &'a Value) -> Option<Ret<'a>> {
         NaturalTimes, RecursiveRecordMerge, RecursiveRecordTypeMerge,
         RightBiasedRecordMerge, TextAppend,
     };
-    use ValueKind::{
-        BoolLit, EmptyListLit, NEListLit, NaturalLit, RecordLit, RecordType,
-    };
+    use LitKind::{Bool, Natural};
+    use ValueKind::{EmptyListLit, Lit, NEListLit, RecordLit, RecordType};
+
     Some(match (o, x.kind(), y.kind()) {
-        (BoolAnd, BoolLit(true), _) => Ret::ValueRef(y),
-        (BoolAnd, _, BoolLit(true)) => Ret::ValueRef(x),
-        (BoolAnd, BoolLit(false), _) => Ret::ValueKind(BoolLit(false)),
-        (BoolAnd, _, BoolLit(false)) => Ret::ValueKind(BoolLit(false)),
+        (BoolAnd, Lit(Bool(true)), _) => Ret::ValueRef(y),
+        (BoolAnd, _, Lit(Bool(true))) => Ret::ValueRef(x),
+        (BoolAnd, Lit(Bool(false)), _) => Ret::ValueKind(Lit(Bool(false))),
+        (BoolAnd, _, Lit(Bool(false))) => Ret::ValueKind(Lit(Bool(false))),
         (BoolAnd, _, _) if x == y => Ret::ValueRef(x),
-        (BoolOr, BoolLit(true), _) => Ret::ValueKind(BoolLit(true)),
-        (BoolOr, _, BoolLit(true)) => Ret::ValueKind(BoolLit(true)),
-        (BoolOr, BoolLit(false), _) => Ret::ValueRef(y),
-        (BoolOr, _, BoolLit(false)) => Ret::ValueRef(x),
+        (BoolOr, Lit(Bool(true)), _) => Ret::ValueKind(Lit(Bool(true))),
+        (BoolOr, _, Lit(Bool(true))) => Ret::ValueKind(Lit(Bool(true))),
+        (BoolOr, Lit(Bool(false)), _) => Ret::ValueRef(y),
+        (BoolOr, _, Lit(Bool(false))) => Ret::ValueRef(x),
         (BoolOr, _, _) if x == y => Ret::ValueRef(x),
-        (BoolEQ, BoolLit(true), _) => Ret::ValueRef(y),
-        (BoolEQ, _, BoolLit(true)) => Ret::ValueRef(x),
-        (BoolEQ, BoolLit(x), BoolLit(y)) => Ret::ValueKind(BoolLit(x == y)),
-        (BoolEQ, _, _) if x == y => Ret::ValueKind(BoolLit(true)),
-        (BoolNE, BoolLit(false), _) => Ret::ValueRef(y),
-        (BoolNE, _, BoolLit(false)) => Ret::ValueRef(x),
-        (BoolNE, BoolLit(x), BoolLit(y)) => Ret::ValueKind(BoolLit(x != y)),
-        (BoolNE, _, _) if x == y => Ret::ValueKind(BoolLit(false)),
+        (BoolEQ, Lit(Bool(true)), _) => Ret::ValueRef(y),
+        (BoolEQ, _, Lit(Bool(true))) => Ret::ValueRef(x),
+        (BoolEQ, Lit(Bool(x)), Lit(Bool(y))) => {
+            Ret::ValueKind(Lit(Bool(x == y)))
+        }
+        (BoolEQ, _, _) if x == y => Ret::ValueKind(Lit(Bool(true))),
+        (BoolNE, Lit(Bool(false)), _) => Ret::ValueRef(y),
+        (BoolNE, _, Lit(Bool(false))) => Ret::ValueRef(x),
+        (BoolNE, Lit(Bool(x)), Lit(Bool(y))) => {
+            Ret::ValueKind(Lit(Bool(x != y)))
+        }
+        (BoolNE, _, _) if x == y => Ret::ValueKind(Lit(Bool(false))),
 
-        (NaturalPlus, NaturalLit(0), _) => Ret::ValueRef(y),
-        (NaturalPlus, _, NaturalLit(0)) => Ret::ValueRef(x),
-        (NaturalPlus, NaturalLit(x), NaturalLit(y)) => {
-            Ret::ValueKind(NaturalLit(x + y))
-        }
-        (NaturalTimes, NaturalLit(0), _) => Ret::ValueKind(NaturalLit(0)),
-        (NaturalTimes, _, NaturalLit(0)) => Ret::ValueKind(NaturalLit(0)),
-        (NaturalTimes, NaturalLit(1), _) => Ret::ValueRef(y),
-        (NaturalTimes, _, NaturalLit(1)) => Ret::ValueRef(x),
-        (NaturalTimes, NaturalLit(x), NaturalLit(y)) => {
-            Ret::ValueKind(NaturalLit(x * y))
+        (NaturalPlus, Lit(Natural(0)), _) => Ret::ValueRef(y),
+        (NaturalPlus, _, Lit(Natural(0))) => Ret::ValueRef(x),
+        (NaturalPlus, Lit(Natural(x)), Lit(Natural(y))) => {
+            Ret::ValueKind(Lit(Natural(x + y)))
+        }
+        (NaturalTimes, Lit(Natural(0)), _) => Ret::ValueKind(Lit(Natural(0))),
+        (NaturalTimes, _, Lit(Natural(0))) => Ret::ValueKind(Lit(Natural(0))),
+        (NaturalTimes, Lit(Natural(1)), _) => Ret::ValueRef(y),
+        (NaturalTimes, _, Lit(Natural(1))) => Ret::ValueRef(x),
+        (NaturalTimes, Lit(Natural(x)), Lit(Natural(y))) => {
+            Ret::ValueKind(Lit(Natural(x * y)))
         }
 
         (ListAppend, EmptyListLit(_), _) => Ret::ValueRef(y),
@@ -217,10 +223,11 @@ pub(crate) fn normalize_one_layer(
     expr: ExprKind<Value>,
     env: &NzEnv,
 ) -> ValueKind {
+    use LitKind::Bool;
     use ValueKind::{
-        BoolLit, DoubleLit, EmptyListLit, EmptyOptionalLit, IntegerLit,
-        NEListLit, NEOptionalLit, NaturalLit, PartialExpr, RecordLit,
-        RecordType, UnionConstructor, UnionLit, UnionType,
+        EmptyListLit, EmptyOptionalLit, Lit, NEListLit, NEOptionalLit,
+        PartialExpr, RecordLit, RecordType, UnionConstructor, UnionLit,
+        UnionType,
     };
 
     let ret = match expr {
@@ -240,10 +247,7 @@ pub(crate) fn normalize_one_layer(
         ExprKind::Builtin(b) => Ret::Value(Value::from_builtin_env(b, env)),
         ExprKind::Assert(_) => Ret::Expr(expr),
         ExprKind::App(v, a) => Ret::Value(v.app(a)),
-        ExprKind::BoolLit(b) => Ret::ValueKind(BoolLit(b)),
-        ExprKind::NaturalLit(n) => Ret::ValueKind(NaturalLit(n)),
-        ExprKind::IntegerLit(n) => Ret::ValueKind(IntegerLit(n)),
-        ExprKind::DoubleLit(n) => Ret::ValueKind(DoubleLit(n)),
+        ExprKind::Lit(l) => Ret::ValueKind(Lit(l.clone())),
         ExprKind::SomeLit(e) => Ret::ValueKind(NEOptionalLit(e)),
         ExprKind::EmptyListLit(t) => {
             let arg = match t.kind() {
@@ -279,12 +283,12 @@ pub(crate) fn normalize_one_layer(
         }
         ExprKind::BoolIf(ref b, ref e1, ref e2) => {
             match b.kind() {
-                BoolLit(true) => Ret::ValueRef(e1),
-                BoolLit(false) => Ret::ValueRef(e2),
+                Lit(Bool(true)) => Ret::ValueRef(e1),
+                Lit(Bool(false)) => Ret::ValueRef(e2),
                 _ => {
                     match (e1.kind(), e2.kind()) {
                         // Simplify `if b then True else False`
-                        (BoolLit(true), BoolLit(false)) => Ret::ValueRef(b),
+                        (Lit(Bool(true)), Lit(Bool(false))) => Ret::ValueRef(b),
                         _ if e1 == e2 => Ret::ValueRef(e1),
                         _ => Ret::Expr(expr),
                     }
diff --git a/dhall/src/semantics/nze/value.rs b/dhall/src/semantics/nze/value.rs
index 0df3c74..2ae6852 100644
--- a/dhall/src/semantics/nze/value.rs
+++ b/dhall/src/semantics/nze/value.rs
@@ -9,8 +9,8 @@ use crate::semantics::{
     TyExpr, VarEnv,
 };
 use crate::syntax::{
-    BinOp, Builtin, Const, ExprKind, Integer, InterpolatedTextContents, Label,
-    NaiveDouble, Natural, Span,
+    BinOp, Builtin, Const, ExprKind, InterpolatedTextContents, Label, LitKind,
+    Span,
 };
 use crate::{NormalizedExpr, ToExprOptions};
 
@@ -76,10 +76,7 @@ pub(crate) enum ValueKind {
 
     Var(NzVar),
     Const(Const),
-    BoolLit(bool),
-    NaturalLit(Natural),
-    IntegerLit(Integer),
-    DoubleLit(NaiveDouble),
+    Lit(LitKind),
     EmptyOptionalLit(Value),
     NEOptionalLit(Value),
     // EmptyListLit(t) means `[] : List t`, not `[] : t`
@@ -205,10 +202,7 @@ impl Value {
                     closure.to_hir(venv),
                 ),
                 ValueKind::Const(c) => ExprKind::Const(*c),
-                ValueKind::BoolLit(b) => ExprKind::BoolLit(*b),
-                ValueKind::NaturalLit(n) => ExprKind::NaturalLit(*n),
-                ValueKind::IntegerLit(n) => ExprKind::IntegerLit(*n),
-                ValueKind::DoubleLit(n) => ExprKind::DoubleLit(*n),
+                ValueKind::Lit(l) => ExprKind::Lit(l.clone()),
                 ValueKind::EmptyOptionalLit(n) => ExprKind::App(
                     Value::from_builtin(Builtin::OptionalNone).to_hir(venv),
                     n.to_hir(venv),
@@ -317,12 +311,7 @@ impl ValueKind {
 
     pub(crate) fn normalize(&self) {
         match self {
-            ValueKind::Var(..)
-            | ValueKind::Const(_)
-            | ValueKind::BoolLit(_)
-            | ValueKind::NaturalLit(_)
-            | ValueKind::IntegerLit(_)
-            | ValueKind::DoubleLit(_) => {}
+            ValueKind::Var(..) | ValueKind::Const(_) | ValueKind::Lit(_) => {}
 
             ValueKind::EmptyOptionalLit(tth) | ValueKind::EmptyListLit(tth) => {
                 tth.normalize();