From 2f04c172fe74981be82149823d96574f7ff4383f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakub=20=C5=BD=C3=A1dn=C3=ADk?= <kubouch@gmail.com>
Date: Sun, 12 Sep 2021 14:12:53 +0300
Subject: [PATCH] Add floating point support for ranges

---
 crates/nu-protocol/src/value/range.rs | 41 +++++++++++++++++++--------
 1 file changed, 29 insertions(+), 12 deletions(-)

diff --git a/crates/nu-protocol/src/value/range.rs b/crates/nu-protocol/src/value/range.rs
index ff138e4af6..2832d09b2b 100644
--- a/crates/nu-protocol/src/value/range.rs
+++ b/crates/nu-protocol/src/value/range.rs
@@ -1,3 +1,5 @@
+use std::cmp::Ordering;
+
 use crate::{
     ast::{RangeInclusion, RangeOperator},
     *,
@@ -150,31 +152,46 @@ impl RangeIterator {
     }
 }
 
+// Compare two floating point numbers. The decision interval for equality is dynamically scaled
+// based on the value being compared.
+fn compare_floats(val: f64, other: f64) -> Option<Ordering> {
+    let prec = val * f64::EPSILON;
+
+    if (other - val).abs() < prec.abs() {
+        return Some(Ordering::Equal);
+    }
+
+    val.partial_cmp(&other)
+}
+
 impl Iterator for RangeIterator {
     type Item = Value;
     fn next(&mut self) -> Option<Self::Item> {
-        use std::cmp::Ordering;
         if self.done {
             return None;
         }
 
         let ordering = if matches!(self.end, Value::Nothing { .. }) {
-            Ordering::Less
+            Some(Ordering::Less)
         } else {
             match (&self.curr, &self.end) {
-                (Value::Int { val: curr, .. }, Value::Int { val: end, .. }) => curr.cmp(end),
-                // (Value::Float { val: curr, .. }, Value::Float { val: end, .. }) => curr.cmp(end),
-                // (Value::Float { val: curr, .. }, Value::Int { val: end, .. }) => curr.cmp(end),
-                // (Value::Int { val: curr, .. }, Value::Float { val: end, .. }) => curr.cmp(end),
-                _ => {
-                    self.done = true;
-                    return Some(Value::Error {
-                        error: ShellError::CannotCreateRange(self.span),
-                    });
-                }
+                (Value::Int { val: curr, .. }, Value::Int { val: end, .. }) => Some(curr.cmp(end)),
+                (Value::Float { val: curr, .. }, Value::Float { val: end, .. }) =>  compare_floats(*curr, *end),
+                (Value::Float { val: curr, .. }, Value::Int { val: end, .. }) => compare_floats(*curr, *end as f64),
+                (Value::Int { val: curr, .. }, Value::Float { val: end, .. }) => compare_floats(*curr as f64, *end),
+                _ => None,
             }
         };
 
+        let ordering = if let Some(ord) = ordering {
+            ord
+        } else {
+            self.done = true;
+            return Some(Value::Error {
+                error: ShellError::CannotCreateRange(self.span),
+            });
+        };
+
         let desired_ordering = if self.moves_up {
             Ordering::Less
         } else {