Introducing Scripts

A sequence of instructions. A client compiles the script and then uses
the compiled script to construction a transaction. Then it adds a
adds a blockhash, signs the transaction, and sends it off for
processing.

runtime/src/bank_client.rs

@@ -1,6 +1,8 @@
 use crate::bank::Bank;
-use solana_sdk::signature::Keypair;
-use solana_sdk::transaction::{Transaction, TransactionError};
+use solana_sdk::pubkey::Pubkey;
+use solana_sdk::signature::{Keypair, KeypairUtil};
+use solana_sdk::system_instruction::SystemInstruction;
+use solana_sdk::transaction::{Script, Transaction, TransactionError};
 
 pub struct BankClient<'a> {
     bank: &'a Bank,
@@ -12,8 +14,23 @@ impl<'a> BankClient<'a> {
         Self { bank, keypair }
     }
 
-    pub fn process_transaction(&self, tx: &mut Transaction) -> Result<(), TransactionError> {
+    pub fn pubkey(&self) -> Pubkey {
+        self.keypair.pubkey()
+    }
+
+    pub fn process_transaction(&self, mut tx: Transaction) -> Result<(), TransactionError> {
         tx.sign(&[&self.keypair], self.bank.last_blockhash());
-        self.bank.process_transaction(tx)
+        self.bank.process_transaction(&mut tx)
+    }
+
+    /// Create and process a transaction.
+    pub fn process_script(&self, script: Script) -> Result<(), TransactionError> {
+        self.process_transaction(Transaction::new(script))
+    }
+
+    /// Transfer lamports to pubkey
+    pub fn transfer(&self, lamports: u64, pubkey: &Pubkey) -> Result<(), TransactionError> {
+        let move_instruction = SystemInstruction::new_move(&self.pubkey(), pubkey, lamports);
+        self.process_script(vec![move_instruction])
     }
 }