Update Read Me and optimise code

README.md

@@ -1,2 +1,61 @@
-# NumberShortener
- A number shortening Library for use in android projects
+# Number Shortener
+
+##### A fully customisable number shortening Library for use in android projects
+
+Shortens a given number to at most three digits with an SI unit after
+
+### Samples
+
+1. 987 => 10 h (hecto)
+2. 1234 => 1 k (kilo)
+3. 123456 => 123 k (kilo)
+4. 1234567 => 1 M (mega)
+
+### Usage
+
+#### Kotlin
+
+```kotlin
+    val shorter = (123456).shorten()
+```
+
+#### Java
+
+```java
+    String shorter = NumberShort.INSTANCE.shorten(123456);
+```
+
+#### Parameters
+
+All parameters are optional and with kotlin named parameters can be used just to edit the required parameters
+
+```
+    round: Boolean              // Whether to round off given number
+    suffix: String              // String to add at the end of text after rounding off
+    precision: Int              // The digits to keep after decimal comma
+    roundMode: RoundingMode     // The mode to use for rounding up numbers
+    units: List<String>         // List of units to use after shortening number
+    powers: List<Int>           // Powers to use when shortening
+```
+
+### Contributing
+
+You are welcome to send push requests (Just remember to add you name to the contributers list) or raise issues
+
+### License
+
+```
+ Copyright 2021 Tyganeutronics.com
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+```

library/src/main/java/com/tyganeutronics/numbershortener/extensions.kt

@@ -54,7 +54,7 @@ fun Number.shorten(
     powers: List<Int> = NumberShort.powers
 ): String {
 
-    if (units.size != powers.size) {
+    if (units.size != powers.size && units.isEmpty()) {
         throw IllegalArgumentException("Units List needs to be equal to Powers list")
     }
 
@@ -71,7 +71,10 @@ fun Number.shorten(
 
             val exp = powers.firstOrNull {
                 //@24 start && end => equal
-                val start = if (it == 24) 27 else powers[(powers.indexOf(it) - 1).coerceAtLeast(0)]
+                val start =
+                    if (it == powers.first()) powers.first() - 1 else powers[(powers.indexOf(it) - 1).coerceAtLeast(
+                        0
+                    )]
                 val end = it
                 ten.pow(start).toBigDecimal() > target && ten.pow(end).toBigDecimal() <= target
             } ?: powers.last()