diff --git a/src/engine.rs b/src/engine.rs
index 2c761c7e..3b740b71 100644
--- a/src/engine.rs
+++ b/src/engine.rs
@@ -12,7 +12,7 @@ use crate::r#unsafe::{unsafe_cast_var_name_to_lifetime, unsafe_mut_cast_to_lifet
 use crate::result::EvalAltResult;
 use crate::scope::{EntryType as ScopeEntryType, Scope};
 use crate::token::Position;
-use crate::utils::StaticVec;
+use crate::utils::{StaticVec, StraightHasherBuilder};
 
 #[cfg(not(feature = "no_float"))]
 use crate::parser::FLOAT;
@@ -196,7 +196,7 @@ impl State {
 ///
 /// The key of the `HashMap` is a `u64` hash calculated by the function `calc_fn_hash`.
 #[derive(Debug, Clone, Default)]
-pub struct FunctionsLib(HashMap<u64, Shared<FnDef>>);
+pub struct FunctionsLib(HashMap<u64, Shared<FnDef>, StraightHasherBuilder>);
 
 impl FunctionsLib {
     /// Create a new `FunctionsLib` from a collection of `FnDef`.
@@ -261,7 +261,7 @@ impl From<Vec<(u64, Shared<FnDef>)>> for FunctionsLib {
 }
 
 impl Deref for FunctionsLib {
-    type Target = HashMap<u64, Shared<FnDef>>;
+    type Target = HashMap<u64, Shared<FnDef>, StraightHasherBuilder>;
 
     fn deref(&self) -> &Self::Target {
         &self.0
@@ -269,7 +269,7 @@ impl Deref for FunctionsLib {
 }
 
 impl DerefMut for FunctionsLib {
-    fn deref_mut(&mut self) -> &mut HashMap<u64, Shared<FnDef>> {
+    fn deref_mut(&mut self) -> &mut HashMap<u64, Shared<FnDef>, StraightHasherBuilder> {
         &mut self.0
     }
 }
@@ -952,21 +952,24 @@ impl Engine {
         let mut idx_val = idx_values.pop();
 
         if is_index {
+            let pos = rhs.position();
+
             match rhs {
-                // xxx[idx].dot_rhs... | xxx[idx][dot_rhs]...
+                // xxx[idx].expr... | xxx[idx][expr]...
                 Expr::Dot(x) | Expr::Index(x) => {
+                    let (idx, expr, pos) = x.as_ref();
                     let is_idx = matches!(rhs, Expr::Index(_));
-                    let pos = x.0.position();
-                    let this_ptr = &mut self
-                        .get_indexed_mut(state, lib, obj, is_ref, idx_val, pos, op_pos, false)?;
+                    let idx_pos = idx.position();
+                    let this_ptr = &mut self.get_indexed_mut(
+                        state, lib, obj, is_ref, idx_val, idx_pos, op_pos, false,
+                    )?;
 
                     self.eval_dot_index_chain_helper(
-                        state, lib, this_ptr, &x.1, idx_values, is_idx, x.2, level, new_val,
+                        state, lib, this_ptr, expr, idx_values, is_idx, *pos, level, new_val,
                     )
                 }
                 // xxx[rhs] = new_val
                 _ if new_val.is_some() => {
-                    let pos = rhs.position();
                     let this_ptr = &mut self
                         .get_indexed_mut(state, lib, obj, is_ref, idx_val, pos, op_pos, true)?;
 
@@ -975,16 +978,7 @@ impl Engine {
                 }
                 // xxx[rhs]
                 _ => self
-                    .get_indexed_mut(
-                        state,
-                        lib,
-                        obj,
-                        is_ref,
-                        idx_val,
-                        rhs.position(),
-                        op_pos,
-                        false,
-                    )
+                    .get_indexed_mut(state, lib, obj, is_ref, idx_val, pos, op_pos, false)
                     .map(|v| (v.clone_into_dynamic(), false)),
             }
         } else {
@@ -1050,57 +1044,51 @@ impl Engine {
                     .map(|(v, _)| (v, false))
                 }
                 #[cfg(not(feature = "no_object"))]
-                // {xxx:map}.idx_lhs[idx_expr] | {xxx:map}.dot_lhs.rhs
+                // {xxx:map}.prop[expr] | {xxx:map}.prop.expr
                 Expr::Index(x) | Expr::Dot(x) if obj.is::<Map>() => {
+                    let (prop, expr, pos) = x.as_ref();
                     let is_idx = matches!(rhs, Expr::Index(_));
 
-                    let mut val = if let Expr::Property(p) = &x.0 {
+                    let mut val = if let Expr::Property(p) = prop {
                         let ((prop, _, _), _) = p.as_ref();
                         let index = prop.clone().into();
-                        self.get_indexed_mut(state, lib, obj, is_ref, index, x.2, op_pos, false)?
+                        self.get_indexed_mut(state, lib, obj, is_ref, index, *pos, op_pos, false)?
                     } else {
-                        // Syntax error
-                        return Err(Box::new(EvalAltResult::ErrorDotExpr(
-                            "".into(),
-                            rhs.position(),
-                        )));
+                        unreachable!();
                     };
 
                     self.eval_dot_index_chain_helper(
-                        state, lib, &mut val, &x.1, idx_values, is_idx, x.2, level, new_val,
+                        state, lib, &mut val, expr, idx_values, is_idx, *pos, level, new_val,
                     )
                 }
-                // xxx.idx_lhs[idx_expr] | xxx.dot_lhs.rhs
+                // xxx.prop[expr] | xxx.prop.expr
                 Expr::Index(x) | Expr::Dot(x) => {
-                    let is_idx = matches!(rhs, Expr::Index(_));
+                    let (prop, expr, pos) = x.as_ref();
+                    let is_idx = matches!(expr, Expr::Index(_));
                     let args = &mut [obj, &mut Default::default()];
 
-                    let (mut val, updated) = if let Expr::Property(p) = &x.0 {
+                    let (mut val, updated) = if let Expr::Property(p) = prop {
                         let ((_, getter, _), _) = p.as_ref();
                         let args = &mut args[..1];
-                        self.exec_fn_call(state, lib, getter, true, 0, args, is_ref, None, x.2, 0)?
+                        self.exec_fn_call(state, lib, getter, true, 0, args, is_ref, None, *pos, 0)?
                     } else {
-                        // Syntax error
-                        return Err(Box::new(EvalAltResult::ErrorDotExpr(
-                            "".into(),
-                            rhs.position(),
-                        )));
+                        unreachable!();
                     };
                     let val = &mut val;
                     let target = &mut val.into();
 
                     let (result, may_be_changed) = self.eval_dot_index_chain_helper(
-                        state, lib, target, &x.1, idx_values, is_idx, x.2, level, new_val,
+                        state, lib, target, expr, idx_values, is_idx, *pos, level, new_val,
                     )?;
 
                     // Feed the value back via a setter just in case it has been updated
                     if updated || may_be_changed {
-                        if let Expr::Property(p) = &x.0 {
+                        if let Expr::Property(p) = prop {
                             let ((_, _, setter), _) = p.as_ref();
                             // Re-use args because the first &mut parameter will not be consumed
                             args[1] = val;
                             self.exec_fn_call(
-                                state, lib, setter, true, 0, args, is_ref, None, x.2, 0,
+                                state, lib, setter, true, 0, args, is_ref, None, *pos, 0,
                             )
                             .or_else(|err| match *err {
                                 // If there is no setter, no need to feed it back because the property is read-only
diff --git a/src/module.rs b/src/module.rs
index 498739b7..9e16e276 100644
--- a/src/module.rs
+++ b/src/module.rs
@@ -12,7 +12,7 @@ use crate::parser::{
 use crate::result::EvalAltResult;
 use crate::scope::{Entry as ScopeEntry, EntryType as ScopeEntryType, Scope};
 use crate::token::{Position, Token};
-use crate::utils::StaticVec;
+use crate::utils::{StaticVec, StraightHasherBuilder};
 
 use crate::stdlib::{
     any::TypeId,
@@ -44,10 +44,14 @@ pub struct Module {
     variables: HashMap<String, Dynamic>,
 
     /// Flattened collection of all module variables, including those in sub-modules.
-    all_variables: HashMap<u64, Dynamic>,
+    all_variables: HashMap<u64, Dynamic, StraightHasherBuilder>,
 
     /// External Rust functions.
-    functions: HashMap<u64, (String, FnAccess, StaticVec<TypeId>, CallableFunction)>,
+    functions: HashMap<
+        u64,
+        (String, FnAccess, StaticVec<TypeId>, CallableFunction),
+        StraightHasherBuilder,
+    >,
 
     /// Script-defined functions.
     lib: FunctionsLib,
@@ -57,7 +61,7 @@ pub struct Module {
 
     /// Flattened collection of all external Rust functions, native or scripted,
     /// including those in sub-modules.
-    all_functions: HashMap<u64, CallableFunction>,
+    all_functions: HashMap<u64, CallableFunction, StraightHasherBuilder>,
 }
 
 impl fmt::Debug for Module {
@@ -101,7 +105,7 @@ impl Module {
     /// ```
     pub fn new_with_capacity(capacity: usize) -> Self {
         Self {
-            functions: HashMap::with_capacity(capacity),
+            functions: HashMap::with_capacity_and_hasher(capacity, StraightHasherBuilder),
             ..Default::default()
         }
     }
diff --git a/src/parser.rs b/src/parser.rs
index 688dc7b1..bf668759 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -7,7 +7,7 @@ use crate::error::{LexError, ParseError, ParseErrorType};
 use crate::optimize::{optimize_into_ast, OptimizationLevel};
 use crate::scope::{EntryType as ScopeEntryType, Scope};
 use crate::token::{Position, Token, TokenIterator};
-use crate::utils::StaticVec;
+use crate::utils::{StaticVec, StraightHasherBuilder};
 
 #[cfg(not(feature = "no_module"))]
 use crate::module::ModuleRef;
@@ -1496,22 +1496,21 @@ fn parse_op_assignment_stmt<'a>(
 }
 
 /// Make a dot expression.
-fn make_dot_expr(
-    lhs: Expr,
-    rhs: Expr,
-    op_pos: Position,
-    is_index: bool,
-) -> Result<Expr, ParseError> {
+fn make_dot_expr(lhs: Expr, rhs: Expr, op_pos: Position) -> Result<Expr, ParseError> {
     Ok(match (lhs, rhs) {
-        // idx_lhs[idx_rhs].rhs
+        // idx_lhs[idx_expr].rhs
         // Attach dot chain to the bottom level of indexing chain
         (Expr::Index(x), rhs) => {
-            Expr::Index(Box::new((x.0, make_dot_expr(x.1, rhs, op_pos, true)?, x.2)))
+            let (idx_lhs, idx_expr, pos) = *x;
+            Expr::Index(Box::new((
+                idx_lhs,
+                make_dot_expr(idx_expr, rhs, op_pos)?,
+                pos,
+            )))
         }
         // lhs.id
         (lhs, Expr::Variable(x)) if x.1.is_none() => {
             let (name, pos) = x.0;
-            let lhs = if is_index { lhs.into_property() } else { lhs };
 
             let getter = make_getter(&name);
             let setter = make_setter(&name);
@@ -1519,11 +1518,6 @@ fn make_dot_expr(
 
             Expr::Dot(Box::new((lhs, rhs, op_pos)))
         }
-        (lhs, Expr::Property(x)) => {
-            let lhs = if is_index { lhs.into_property() } else { lhs };
-            let rhs = Expr::Property(x);
-            Expr::Dot(Box::new((lhs, rhs, op_pos)))
-        }
         // lhs.module::id - syntax error
         (_, Expr::Variable(x)) if x.1.is_some() => {
             #[cfg(feature = "no_module")]
@@ -1531,34 +1525,30 @@ fn make_dot_expr(
             #[cfg(not(feature = "no_module"))]
             return Err(PERR::PropertyExpected.into_err(x.1.unwrap().get(0).1));
         }
+        // lhs.prop
+        (lhs, prop @ Expr::Property(_)) => Expr::Dot(Box::new((lhs, prop, op_pos))),
         // lhs.dot_lhs.dot_rhs
         (lhs, Expr::Dot(x)) => {
             let (dot_lhs, dot_rhs, pos) = *x;
             Expr::Dot(Box::new((
                 lhs,
-                Expr::Dot(Box::new((
-                    dot_lhs.into_property(),
-                    dot_rhs.into_property(),
-                    pos,
-                ))),
+                Expr::Dot(Box::new((dot_lhs.into_property(), dot_rhs, pos))),
                 op_pos,
             )))
         }
         // lhs.idx_lhs[idx_rhs]
         (lhs, Expr::Index(x)) => {
-            let (idx_lhs, idx_rhs, pos) = *x;
+            let (dot_lhs, dot_rhs, pos) = *x;
             Expr::Dot(Box::new((
                 lhs,
-                Expr::Index(Box::new((
-                    idx_lhs.into_property(),
-                    idx_rhs.into_property(),
-                    pos,
-                ))),
+                Expr::Index(Box::new((dot_lhs.into_property(), dot_rhs, pos))),
                 op_pos,
             )))
         }
+        // lhs.func()
+        (lhs, func @ Expr::FnCall(_)) => Expr::Dot(Box::new((lhs, func, op_pos))),
         // lhs.rhs
-        (lhs, rhs) => Expr::Dot(Box::new((lhs, rhs.into_property(), op_pos))),
+        _ => unreachable!(),
     })
 }
 
@@ -1822,7 +1812,7 @@ fn parse_binary_op<'a>(
                     _ => (),
                 }
 
-                make_dot_expr(current_lhs, rhs, pos, false)?
+                make_dot_expr(current_lhs, rhs, pos)?
             }
 
             token => return Err(PERR::UnknownOperator(token.into()).into_err(pos)),
@@ -2493,22 +2483,20 @@ pub fn parse_global_expr<'a>(
 fn parse_global_level<'a>(
     input: &mut Peekable<TokenIterator<'a>>,
     max_expr_depth: (usize, usize),
-) -> Result<(Vec<Stmt>, HashMap<u64, FnDef>), ParseError> {
+) -> Result<(Vec<Stmt>, Vec<FnDef>), ParseError> {
     let mut statements = Vec::<Stmt>::new();
-    let mut functions = HashMap::<u64, FnDef>::new();
+    let mut functions = HashMap::with_hasher(StraightHasherBuilder);
     let mut state = ParseState::new(max_expr_depth.0);
 
     while !input.peek().unwrap().0.is_eof() {
         // Collect all the function definitions
         #[cfg(not(feature = "no_function"))]
         {
-            let mut access = FnAccess::Public;
-            let mut must_be_fn = false;
-
-            if match_token(input, Token::Private)? {
-                access = FnAccess::Private;
-                must_be_fn = true;
-            }
+            let (access, must_be_fn) = if match_token(input, Token::Private)? {
+                (FnAccess::Private, true)
+            } else {
+                (FnAccess::Public, false)
+            };
 
             match input.peek().unwrap() {
                 (Token::Fn, _) => {
@@ -2565,7 +2553,7 @@ fn parse_global_level<'a>(
         }
     }
 
-    Ok((statements, functions))
+    Ok((statements, functions.into_iter().map(|(_, v)| v).collect()))
 }
 
 /// Run the parser on an input stream, returning an AST.
@@ -2576,9 +2564,8 @@ pub fn parse<'a>(
     optimization_level: OptimizationLevel,
     max_expr_depth: (usize, usize),
 ) -> Result<AST, ParseError> {
-    let (statements, functions) = parse_global_level(input, max_expr_depth)?;
+    let (statements, lib) = parse_global_level(input, max_expr_depth)?;
 
-    let lib = functions.into_iter().map(|(_, v)| v).collect();
     Ok(
         // Optimize AST
         optimize_into_ast(engine, scope, statements, lib, optimization_level),
diff --git a/src/utils.rs b/src/utils.rs
index c396df19..ccd3d6be 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -11,7 +11,7 @@ use crate::stdlib::{
     borrow::Borrow,
     boxed::Box,
     fmt,
-    hash::{Hash, Hasher},
+    hash::{BuildHasher, Hash, Hasher},
     iter::FromIterator,
     mem,
     mem::MaybeUninit,
@@ -27,6 +27,48 @@ use crate::stdlib::collections::hash_map::DefaultHasher;
 #[cfg(feature = "no_std")]
 use ahash::AHasher;
 
+/// A hasher that only takes one single `u64` and returns it as a hash key.
+///
+/// # Panics
+///
+/// Panics when hashing any data type other than a `u64`.
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash, Default)]
+pub struct StraightHasher(u64);
+
+impl Hasher for StraightHasher {
+    #[inline(always)]
+    fn finish(&self) -> u64 {
+        self.0
+    }
+    #[inline]
+    fn write(&mut self, bytes: &[u8]) {
+        let mut key = [0_u8; 8];
+        key.copy_from_slice(&bytes[..8]); // Panics if fewer than 8 bytes
+        self.0 = u64::from_le_bytes(key);
+    }
+}
+
+impl StraightHasher {
+    /// Create a `StraightHasher`.
+    #[inline(always)]
+    pub fn new() -> Self {
+        Self(0)
+    }
+}
+
+/// A hash builder for `StraightHasher`.
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash, Default)]
+pub struct StraightHasherBuilder;
+
+impl BuildHasher for StraightHasherBuilder {
+    type Hasher = StraightHasher;
+
+    #[inline(always)]
+    fn build_hasher(&self) -> Self::Hasher {
+        StraightHasher::new()
+    }
+}
+
 /// Calculate a `u64` hash key from a module-qualified function name and parameter types.
 ///
 /// Module names are passed in via `&str` references from an iterator.
@@ -108,6 +150,7 @@ pub struct StaticVec<T> {
 const MAX_STATIC_VEC: usize = 4;
 
 impl<T> Drop for StaticVec<T> {
+    #[inline(always)]
     fn drop(&mut self) {
         self.clear();
     }
@@ -174,6 +217,7 @@ impl<T> FromIterator<T> for StaticVec<T> {
 
 impl<T> StaticVec<T> {
     /// Create a new `StaticVec`.
+    #[inline(always)]
     pub fn new() -> Self {
         Default::default()
     }
@@ -189,6 +233,7 @@ impl<T> StaticVec<T> {
         self.len = 0;
     }
     /// Extract a `MaybeUninit` into a concrete initialized type.
+    #[inline(always)]
     fn extract(value: MaybeUninit<T>) -> T {
         unsafe { value.assume_init() }
     }
@@ -250,6 +295,7 @@ impl<T> StaticVec<T> {
         );
     }
     /// Is data stored in fixed-size storage?
+    #[inline(always)]
     fn is_fixed_storage(&self) -> bool {
         self.len <= MAX_STATIC_VEC
     }
@@ -359,10 +405,12 @@ impl<T> StaticVec<T> {
         result
     }
     /// Get the number of items in this `StaticVec`.
+    #[inline(always)]
     pub fn len(&self) -> usize {
         self.len
     }
     /// Is this `StaticVec` empty?
+    #[inline(always)]
     pub fn is_empty(&self) -> bool {
         self.len == 0
     }
@@ -605,41 +653,48 @@ pub struct ImmutableString(Shared<String>);
 impl Deref for ImmutableString {
     type Target = String;
 
+    #[inline(always)]
     fn deref(&self) -> &Self::Target {
         &self.0
     }
 }
 
 impl AsRef<String> for ImmutableString {
+    #[inline(always)]
     fn as_ref(&self) -> &String {
         &self.0
     }
 }
 
 impl Borrow<str> for ImmutableString {
+    #[inline(always)]
     fn borrow(&self) -> &str {
         self.0.as_str()
     }
 }
 
 impl From<&str> for ImmutableString {
+    #[inline(always)]
     fn from(value: &str) -> Self {
         Self(value.to_string().into())
     }
 }
 impl From<String> for ImmutableString {
+    #[inline(always)]
     fn from(value: String) -> Self {
         Self(value.into())
     }
 }
 
 impl From<Box<String>> for ImmutableString {
+    #[inline(always)]
     fn from(value: Box<String>) -> Self {
         Self(value.into())
     }
 }
 
 impl From<ImmutableString> for String {
+    #[inline(always)]
     fn from(value: ImmutableString) -> Self {
         value.into_owned()
     }
@@ -648,42 +703,49 @@ impl From<ImmutableString> for String {
 impl FromStr for ImmutableString {
     type Err = ();
 
+    #[inline(always)]
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         Ok(Self(s.to_string().into()))
     }
 }
 
 impl FromIterator<char> for ImmutableString {
+    #[inline(always)]
     fn from_iter<T: IntoIterator<Item = char>>(iter: T) -> Self {
         Self(iter.into_iter().collect::<String>().into())
     }
 }
 
 impl<'a> FromIterator<&'a char> for ImmutableString {
+    #[inline(always)]
     fn from_iter<T: IntoIterator<Item = &'a char>>(iter: T) -> Self {
         Self(iter.into_iter().cloned().collect::<String>().into())
     }
 }
 
 impl<'a> FromIterator<&'a str> for ImmutableString {
+    #[inline(always)]
     fn from_iter<T: IntoIterator<Item = &'a str>>(iter: T) -> Self {
         Self(iter.into_iter().collect::<String>().into())
     }
 }
 
 impl<'a> FromIterator<String> for ImmutableString {
+    #[inline(always)]
     fn from_iter<T: IntoIterator<Item = String>>(iter: T) -> Self {
         Self(iter.into_iter().collect::<String>().into())
     }
 }
 
 impl fmt::Display for ImmutableString {
+    #[inline(always)]
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Display::fmt(self.0.as_str(), f)
     }
 }
 
 impl fmt::Debug for ImmutableString {
+    #[inline(always)]
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Debug::fmt(self.0.as_str(), f)
     }
@@ -818,6 +880,7 @@ impl Add<char> for &ImmutableString {
 }
 
 impl AddAssign<char> for ImmutableString {
+    #[inline(always)]
     fn add_assign(&mut self, rhs: char) {
         self.make_mut().push(rhs);
     }
@@ -832,6 +895,7 @@ impl ImmutableString {
     }
     /// Make sure that the `ImmutableString` is unique (i.e. no other outstanding references).
     /// Then return a mutable reference to the `String`.
+    #[inline(always)]
     pub fn make_mut(&mut self) -> &mut String {
         shared_make_mut(&mut self.0)
     }