diff --git a/src/nodes/eval.rs b/src/nodes/eval.rs
index 33c606b..2ebfee0 100644
--- a/src/nodes/eval.rs
+++ b/src/nodes/eval.rs
@@ -83,41 +83,111 @@ fn collapse_toplevel(nodes: &mut Vec<Node>, mut end: usize) -> Result<(), Error>
             return Err(Error::MissingArgument(node.clone()));
         };
 
-        function.apply_to(n);
+        function.for_float()(n);
 
         nodes.remove(start + index);
         end -= 1;
     }
 
-    macro_rules! collapse_operator {
-        ($operator:expr) => {
-            while let Some(index) = nodes[start..end]
-                .iter()
-                .position(|n| *n == Node::Operator($operator))
-            {
-                let lhs = match nodes.remove(start + index - 1) {
-                    Node::Number(n) => n,
-                    n => return Err(Error::InvalidOperand(n)),
-                };
-                end -= 1;
-                match nodes.get_mut(start + index) {
-                    None => return Err(Error::OutOfBounds(Nodes(nodes.clone()), start + index)),
-
-                    Some(Node::Number(n)) => $operator.apply_to(n, lhs),
-                    Some(n) => return Err(Error::InvalidOperand(n.clone())),
-                };
-
-                nodes.remove(start + index - 1);
-                end -= 1;
-            }
+    while let Some(operator) = nodes[start..end]
+        .iter()
+        .position(|n| *n == Node::Operator(Operator::Exp))
+    {
+        let lhs = match nodes.remove(start + operator - 1) {
+            Node::Number(n) => n,
+            n => return Err(Error::InvalidOperand(n)),
         };
+        end -= 1;
+        match nodes.get_mut(start + operator) {
+            None => return Err(Error::OutOfBounds(Nodes(nodes.clone()), start + operator)),
+
+            Some(Node::Number(n)) => n.pow_from(lhs),
+            Some(n) => return Err(Error::InvalidOperand(n.clone())),
+        };
+
+        nodes.remove(start + operator - 1);
+        end -= 1;
     }
 
-    collapse_operator!(Operator::Exp);
-    collapse_operator!(Operator::Div);
-    collapse_operator!(Operator::Mult);
-    collapse_operator!(Operator::Minus);
-    collapse_operator!(Operator::Plus);
+    while let Some(operator) = nodes[start..end]
+        .iter()
+        .position(|n| *n == Node::Operator(Operator::Div))
+    {
+        let lhs = match nodes.remove(start + operator - 1) {
+            Node::Number(n) => n,
+            n => return Err(Error::InvalidOperand(n)),
+        };
+        end -= 1;
+        match nodes.get_mut(start + operator) {
+            None => return Err(Error::OutOfBounds(Nodes(nodes.clone()), start + operator)),
+
+            Some(Node::Number(n)) => n.div_from(lhs),
+            Some(n) => return Err(Error::InvalidOperand(n.clone())),
+        };
+
+        nodes.remove(start + operator - 1);
+        end -= 1;
+    }
+
+    while let Some(operator) = nodes[start..end]
+        .iter()
+        .position(|n| *n == Node::Operator(Operator::Mult))
+    {
+        let lhs = match nodes.remove(start + operator - 1) {
+            Node::Number(n) => n,
+            n => return Err(Error::InvalidOperand(n)),
+        };
+        end -= 1;
+        match nodes.get_mut(start + operator) {
+            None => return Err(Error::OutOfBounds(Nodes(nodes.clone()), start + operator)),
+
+            Some(Node::Number(n)) => n.mul_from(lhs),
+            Some(n) => return Err(Error::InvalidOperand(n.clone())),
+        };
+
+        nodes.remove(start + operator - 1);
+        end -= 1;
+    }
+
+    while let Some(operator) = nodes[start..end]
+        .iter()
+        .position(|n| *n == Node::Operator(Operator::Minus))
+    {
+        let lhs = match nodes.remove(start + operator - 1) {
+            Node::Number(n) => n,
+            n => return Err(Error::InvalidOperand(n)),
+        };
+        end -= 1;
+        match nodes.get_mut(start + operator) {
+            None => return Err(Error::OutOfBounds(Nodes(nodes.clone()), start + operator)),
+
+            Some(Node::Number(n)) => n.sub_from(lhs),
+            Some(n) => return Err(Error::InvalidOperand(n.clone())),
+        };
+
+        nodes.remove(start + operator - 1);
+        end -= 1;
+    }
+
+    while let Some(operator) = nodes[start..end]
+        .iter()
+        .position(|n| *n == Node::Operator(Operator::Plus))
+    {
+        let lhs = match nodes.remove(start + operator - 1) {
+            Node::Number(n) => n,
+            n => return Err(Error::InvalidOperand(n)),
+        };
+        end -= 1;
+        match nodes.get_mut(start + operator) {
+            None => return Err(Error::OutOfBounds(Nodes(nodes.clone()), start + operator)),
+
+            Some(Node::Number(n)) => n.add_from(lhs),
+            Some(n) => return Err(Error::InvalidOperand(n.clone())),
+        };
+
+        nodes.remove(start + operator - 1);
+        end -= 1;
+    }
 
     if nodes.len() > 1 {
         nodes.remove(end);
@@ -127,32 +197,21 @@ fn collapse_toplevel(nodes: &mut Vec<Node>, mut end: usize) -> Result<(), Error>
     Ok(())
 }
 
-impl Operator {
-    fn apply_to(&self, rhs: &mut Float, lhs: Float) {
-        match self {
-            Self::Plus => Float::add_from(rhs, lhs),
-            Self::Minus => Float::sub_from(rhs, lhs),
-            Self::Mult => Float::mul_from(rhs, lhs),
-            Self::Div => Float::div_from(rhs, lhs),
-            Self::Exp => Float::pow_from(rhs, lhs),
-        }
-    }
-}
 impl Function {
-    fn apply_to(&self, n: &mut Float) {
+    fn for_float(&self) -> impl FnMut(&mut Float) {
         match self {
-            Self::Sqrt => Float::sqrt_mut(n),
+            Function::Sqrt => Float::sqrt_mut,
 
-            Self::Ln => Float::ln_mut(n),
+            Function::Ln => Float::ln_mut,
 
-            Self::Sine => Float::sin_mut(n),
-            Self::ArcSine => Float::asin_mut(n),
-            Self::Cosine => Float::cos_mut(n),
-            Self::ArcCosine => Float::acos_mut(n),
-            Self::Tangent => Float::tan_mut(n),
-            Self::ArcTangent => Float::atan_mut(n),
-            Self::Secant => Float::sec_mut(n),
-            Self::CoSecant => Float::csc_mut(n),
+            Function::Sine => Float::sin_mut,
+            Function::ArcSine => Float::asin_mut,
+            Function::Cosine => Float::cos_mut,
+            Function::ArcCosine => Float::acos_mut,
+            Function::Tangent => Float::tan_mut,
+            Function::ArcTangent => Float::atan_mut,
+            Function::Secant => Float::sec_mut,
+            Function::CoSecant => Float::csc_mut,
         }
     }
 }
diff --git a/src/nodes/parse.rs b/src/nodes/parse.rs
index e3da6e6..96d4236 100644
--- a/src/nodes/parse.rs
+++ b/src/nodes/parse.rs
@@ -1,10 +1,7 @@
 use core::f64;
 use std::str::FromStr;
 
-use rug::{
-    Float,
-    float::{self, ParseFloatError},
-};
+use rug::{Float, float::ParseFloatError};
 
 use crate::nodes::{Function, Node, Nodes, Operator};
 
@@ -13,7 +10,7 @@ impl Node {
         Ok(match s {
             "c" => Self::from(299_792_458),
             "A" => Self::from(6.02214076e23),
-            "pi" | "π" => Self::from(float::Constant::Pi),
+            "pi" | "π" => Self::from(f64::consts::PI),
             // Planck's constant, in J*s (joule-seconds)
             "h" => Self::from(6.62607015e-34),
             "e" => Self::from(f64::consts::E),
diff --git a/src/nodes/tests.rs b/src/nodes/tests.rs
index 2f22d8a..15b6c21 100644
--- a/src/nodes/tests.rs
+++ b/src/nodes/tests.rs
@@ -51,8 +51,3 @@ fn constant_implicit_mult() {
     assert_eq!(eval("2pi"), 6.283185307179586);
     assert_eq!(eval("pi2"), 6.283185307179586);
 }
-
-#[test]
-fn pi_precision() {
-    assert_eq!(eval("sin(pi)"), 0.)
-}