feat: increase PREC 512 -> 2048

unfortunately it isn't this easy for n > 0.001,
a similar strategy seems to prefer printing eg 1.0 * 10^-1

src/formatting.rs

@@ -19,10 +19,22 @@ pub fn pretty_eval(mut input: String) -> Result<String, Error> {
         .is_some();
 
     let result = nodes::eval(&input)?;
-    let significant_digits = get_significant_digits(&result).min(MAX_DIGITS);
+    let display_digits =
+        get_significant_digits(&result)
+            .min(MAX_DIGITS)
+            .max(if result >= 1000 || result < 1 {
+                1
+            } else if result >= 100 {
+                3
+            } else if result >= 10 {
+                2
+            // if result >= 1
+            } else {
+                1
+            });
 
     Ok(format!(
-        "{}{}{result:.significant_digits$}{}",
+        "{}{}{result:.display_digits$}{}",
         " ".repeat(leading_spaces),
         if should_add_back_equals && should_add_back_alignment {
             "& = "
@@ -34,7 +46,8 @@ pub fn pretty_eval(mut input: String) -> Result<String, Error> {
             ""
         },
         if should_add_back_backslash { " \\" } else { "" }
-    ))
+    )
+    .replace('e', " * 10^"))
 }
 #[test]
 fn test_character_readdition() {
@@ -43,9 +56,19 @@ fn test_character_readdition() {
     assert_eq!(pretty_eval(" & 11".into()).unwrap(), " & 11");
     assert_eq!(pretty_eval(" & 11 \\".into()).unwrap(), " & 11 \\");
 }
+#[test]
+fn test_basic_up_to_999() {
+    assert_eq!(pretty_eval("1".into()).unwrap(), "1");
+    assert_eq!(pretty_eval("10".into()).unwrap(), "10");
+    assert_eq!(pretty_eval("100".into()).unwrap(), "100");
+    assert_eq!(pretty_eval("999".into()).unwrap(), "999");
+    assert_eq!(pretty_eval("1000".into()).unwrap(), "1 * 10^3");
+
+    assert_eq!(pretty_eval("11.111111".into()).unwrap(), "11.111111");
+}
 
 pub fn get_significant_digits(n: &Float) -> usize {
-    let raw_string: String = format!("{n}").chars().filter(|c| *c != '.').collect();
+    let raw_string = n.to_string().replace('.', "");
 
     let mut consecutive_zeros = 0;
     let mut consecutive_nines = 0;

src/nodes/mod.rs

@@ -25,7 +25,7 @@ pub fn eval(s: &str) -> Result<rug::Float, Error> {
     Ok(Nodes::from_str(s)?.evaluate()?)
 }
 
-pub const PREC: u32 = 512;
+pub const PREC: u32 = 2048;
 
 #[derive(Debug, Default, Clone, PartialEq)]
 pub struct Nodes(Vec<Node>);