Use u64 behind the scenes for solana-tokens (#13815)

* Use u64 behind the scenes for Allocations

* Fixup readme

* Clippy and remove errant comments

tokens/src/token_display.rs

@@ -1,3 +1,5 @@
+use solana_account_decoder::parse_token::token_amount_to_ui_amount;
+use solana_sdk::native_token::lamports_to_sol;
 use std::{
     fmt::{Debug, Display, Formatter, Result},
     ops::Add,
@@ -12,25 +14,39 @@ pub enum TokenType {
 }
 
 pub struct Token {
-    amount: f64,
+    amount: u64,
+    decimals: u8,
     token_type: TokenType,
 }
 
 impl Token {
     fn write_with_symbol(&self, f: &mut Formatter) -> Result {
         match &self.token_type {
-            TokenType::Sol => write!(f, "{}{}", SOL_SYMBOL, self.amount,),
-            TokenType::SplToken => write!(f, "{} tokens", self.amount,),
+            TokenType::Sol => {
+                let amount = lamports_to_sol(self.amount);
+                write!(f, "{}{}", SOL_SYMBOL, amount)
+            }
+            TokenType::SplToken => {
+                let amount = token_amount_to_ui_amount(self.amount, self.decimals).ui_amount;
+                write!(f, "{} tokens", amount)
+            }
         }
     }
 
-    pub fn from(amount: f64, is_sol: bool) -> Self {
-        let token_type = if is_sol {
-            TokenType::Sol
-        } else {
-            TokenType::SplToken
-        };
-        Self { amount, token_type }
+    pub fn sol(amount: u64) -> Self {
+        Self {
+            amount,
+            decimals: 9,
+            token_type: TokenType::Sol,
+        }
+    }
+
+    pub fn spl_token(amount: u64, decimals: u8) -> Self {
+        Self {
+            amount,
+            decimals,
+            token_type: TokenType::SplToken,
+        }
     }
 }
 
@@ -53,6 +69,7 @@ impl Add for Token {
         if self.token_type == other.token_type {
             Self {
                 amount: self.amount + other.amount,
+                decimals: self.decimals,
                 token_type: self.token_type,
             }
         } else {