Removed trailing zeroes from results.

kalk_cli/Cargo.lock

@@ -134,6 +134,7 @@ version = "0.1.0"
 dependencies = [
  "phf",
  "rug",
+ "test-case",
 ]
 
 [[package]]
@@ -392,6 +393,18 @@ dependencies = [
  "unicode-xid",
 ]
 
+[[package]]
+name = "test-case"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "199464148b42bcf3da8b2a56f6ee87ca68f47402496d1268849291ec9fb463c8"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+ "version_check",
+]
+
 [[package]]
 name = "unicode-segmentation"
 version = "1.6.0"
@@ -416,6 +429,12 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "936e4b492acfd135421d8dca4b1aa80a7bfc26e702ef3af710e0752684df5372"
 
+[[package]]
+name = "version_check"
+version = "0.9.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5a972e5669d67ba988ce3dc826706fb0a8b01471c088cb0b6110b805cc36aed"
+
 [[package]]
 name = "void"
 version = "1.0.2"

kalk_cli/src/output.rs

@@ -4,13 +4,35 @@ use kalk::parser::{self};
 pub fn eval(parser: &mut parser::Context, input: &str) {
     match parser::parse(parser, input, 53) {
         Ok(Some(result)) => {
-            if result.clone().fract() == 0 {
+            if result.is_infinite() {
+                err("Too big to process.");
+            } else if result > 100_000_000 || result < -100_000_00 {
+                let sign = if result >= 0 { "" } else { "-" };
+                let (_, digits, exp) = result.to_sign_string_exp(10, None);
+                let value = format!(
+                    "{}.{}",
+                    digits[0..1].to_string(),
+                    digits[1..].to_string().trim_end_matches('0')
+                );
+
+                println!("{}{}*10^{}", sign, value, exp.unwrap() - 1);
+            } else if result.clone().fract() == 0 {
                 println!("{}", result.to_integer().unwrap());
             } else {
-                println!("{}", result);
+                println!(
+                    "{}",
+                    result
+                        .to_string()
+                        .trim_end_matches('0')
+                        .trim_end_matches('.')
+                );
             }
         }
         Ok(None) => print!(""),
-        Err(err) => println!("{}", Red.paint(err)),
+        Err(msg) => err(&msg),
     }
 }
+
+fn err(msg: &str) {
+    println!("{}", Red.paint(msg));
+}