From 6dc339887a20cf058ef2e6b58cc05459f2938628 Mon Sep 17 00:00:00 2001
From: Tad Hardesty <tad@platymuus.com>
Date: Tue, 16 Nov 2021 22:46:51 -0800
Subject: [PATCH] Reduce the size of Expression

---
 crates/dreammaker/src/ast.rs       | 19 +++++++++++--------
 crates/dreammaker/src/constants.rs |  6 +++---
 crates/dreammaker/src/parser.rs    | 20 ++++++++++++--------
 3 files changed, 26 insertions(+), 19 deletions(-)

diff --git a/crates/dreammaker/src/ast.rs b/crates/dreammaker/src/ast.rs
index 229e1643..65f9f7f4 100644
--- a/crates/dreammaker/src/ast.rs
+++ b/crates/dreammaker/src/ast.rs
@@ -84,6 +84,7 @@ impl<'a, T: fmt::Display + ?Sized> fmt::Display for Around<'a, T> {
 }
 
 pub type Ident = String;
+pub type Ident2 = Box<str>;
 
 /// The DM path operators.
 ///
@@ -329,8 +330,8 @@ pub enum NewType {
     Prefab(Box<Prefab>),
     /// A "mini-expression" in which to find the prefab to instantiate.
     MiniExpr {
-        ident: Ident,
-        fields: Vec<Field>,
+        ident: Ident2,
+        fields: Box<[Field]>,
     },
 }
 
@@ -341,11 +342,11 @@ pub enum Expression {
     /// then its follows, then its unary operators in reverse order.
     Base {
         /// The unary operations applied to this value, in reverse order.
-        unary: Vec<UnaryOp>,
+        unary: Box<[UnaryOp]>,
         /// The term of the expression.
         term: Box<Spanned<Term>>,
         /// The follow operations applied to this value.
-        follow: Vec<Spanned<Follow>>,
+        follow: Box<[Spanned<Follow>]>,
     },
     /// A binary operation.
     BinaryOp {
@@ -435,12 +436,14 @@ impl Expression {
         match self {
             Expression::Base { unary, term, follow: _ } => {
                 guard!(let Some(truthy) = term.elem.is_truthy() else {
-                    return None
+                    return None;
                 });
                 let mut negation = false;
-                for u in unary {
+                for u in unary.iter() {
                     if let UnaryOp::Not = u {
                         negation = !negation;
+                    } else {
+                        return None;
                     }
                 }
                 if negation {
@@ -538,7 +541,7 @@ pub enum Term {
         /// The type to be instantiated.
         type_: NewType,
         /// The list of arguments to pass to the `New()` proc.
-        args: Option<Vec<Expression>>,
+        args: Option<Box<[Expression]>>,
     },
     /// A `list` call. Associations are represented by assignment expressions.
     List(Vec<Expression>),
@@ -1011,7 +1014,7 @@ impl VarSuffix {
         } else {
             Some(Expression::from(Term::New {
                 type_: NewType::Prefab(Box::new(Prefab::from(vec![(PathOp::Slash, "list".to_owned())]))),
-                args: Some(args),
+                args: Some(args.into_boxed_slice()),
             }))
         }
     }
diff --git a/crates/dreammaker/src/constants.rs b/crates/dreammaker/src/constants.rs
index d89a1289..ca3cc5e2 100644
--- a/crates/dreammaker/src/constants.rs
+++ b/crates/dreammaker/src/constants.rs
@@ -562,10 +562,10 @@ impl<'a> ConstantFolder<'a> {
                     None
                 };
                 let mut term = self.term(term.elem, base_type_hint)?;
-                for each in follow {
+                for each in Vec::from(follow).into_iter() {
                     term = self.follow(term, each.elem)?;
                 }
-                for each in unary.into_iter().rev() {
+                for each in Vec::from(unary).into_iter().rev() {
                     term = self.unary(term, each)?;
                 }
                 term
@@ -717,7 +717,7 @@ impl<'a> ConstantFolder<'a> {
                     NewType::MiniExpr { .. } => return Err(self.error("non-constant new expression")),
                 },
                 args: match args {
-                    Some(args) => Some(self.arguments(args)?),
+                    Some(args) => Some(self.arguments(args.into())?),
                     None => None,
                 },
             },
diff --git a/crates/dreammaker/src/parser.rs b/crates/dreammaker/src/parser.rs
index 6f6f11de..71496e96 100644
--- a/crates/dreammaker/src/parser.rs
+++ b/crates/dreammaker/src/parser.rs
@@ -1900,9 +1900,9 @@ impl<'ctx, 'an, 'inp> Parser<'ctx, 'an, 'inp> {
         }*/
 
         success(Expression::Base {
-            unary: unary_ops,
+            unary: unary_ops.into_boxed_slice(),
             term: Box::new(term),
-            follow,
+            follow: follow.into_boxed_slice(),
         })
     }
 
@@ -1934,9 +1934,10 @@ impl<'ctx, 'an, 'inp> Parser<'ctx, 'an, 'inp> {
                         NewType::Prefab(require!(self.prefab_ex(vec![(PathOp::Dot, ident)])))
                     } else {
                         // bare dot
-                        let fields = Vec::new();
-                        let ident = ".".to_owned();
-                        NewType::MiniExpr { ident, fields }
+                        NewType::MiniExpr {
+                            ident: ".".into(),
+                            fields: Default::default(),
+                        }
                     }
                 } else if let Some(ident) = self.ident()? {
                     let mut fields = Vec::new();
@@ -1944,7 +1945,10 @@ impl<'ctx, 'an, 'inp> Parser<'ctx, 'an, 'inp> {
                     while let Some(item) = self.field(&mut belongs_to, false)? {
                         fields.push(item);
                     }
-                    NewType::MiniExpr { ident, fields }
+                    NewType::MiniExpr {
+                        ident: ident.into(),
+                        fields: fields.into_boxed_slice(),
+                    }
                 } else if let Some(path) = self.prefab()? {
                     NewType::Prefab(path)
                 } else {
@@ -1953,11 +1957,11 @@ impl<'ctx, 'an, 'inp> Parser<'ctx, 'an, 'inp> {
 
                 // try to read an arglist
                 // TODO: communicate what type is being new'd somehow
-                let a = self.arguments(&[], "New")?;
+                let args = self.arguments(&[], "New")?;
 
                 Term::New {
                     type_: t,
-                    args: a,
+                    args: args.map(Vec::into_boxed_slice),
                 }
             },