changed map and functions to just use principal.

src/tutorial.md

@@ -643,7 +643,7 @@ First we're going to set up the data variables we need.
 ```clojure
 ;; Define the contract's data variables
 (define-map deposits { owner: principal } { amount: uint })
-(define-map loans {owner : principal} { amount: uint, last-interaction-block: uint })
+(define-map loans principal { amount: uint, last-interaction-block: uint })
 
 (define-data-var total-deposits uint u0)
 (define-data-var total-loans uint u0)
@@ -687,14 +687,14 @@ Next up, let's write the `borrow` function.
     (let (
         (user-deposit (default-to u0 (get amount (map-get? deposits { owner: tx-sender }))))
         (allowed-borrow (/ user-deposit u2))
-        (current-loan-details (default-to { amount: u0, last-interaction-block: u0 } (map-get? loans { owner: tx-sender })))
+        (current-loan-details (default-to { amount: u0, last-interaction-block: u0 } (map-get? loans tx-sender )))
         (accrued-interest (calculate-accrued-interest (get amount current-loan-details) (get last-interaction-block current-loan-details)))
         (total-due (+ (get amount current-loan-details) (unwrap! accrued-interest (err u8))))
         (new-loan (+ total-due amount))
     )
         (asserts! (<= amount allowed-borrow) (err u7))
         (try! (contract-call? .asset transfer amount (as-contract tx-sender) tx-sender none))
-        (map-set loans { owner: tx-sender } { amount: new-loan, last-interaction-block: block-height })
+        (map-set loans tx-sender { amount: new-loan, last-interaction-block: block-height })
         (ok true)
     )
 )
@@ -718,13 +718,13 @@ Next up we have the repay function.
 ;; Users can repay their sBTC loans
 (define-public (repay (amount uint))
     (let (
-        (current-loan-details (default-to { amount: u0, last-interaction-block: u0 } (map-get? loans { owner: tx-sender })))
+        (current-loan-details (default-to { amount: u0, last-interaction-block: u0 } (map-get? loans tx-sender)))
         (accrued-interest (calculate-accrued-interest (get amount current-loan-details) (get last-interaction-block current-loan-details)))
         (total-due (+ (get amount current-loan-details) (unwrap! accrued-interest (err u8))))
     )
         (asserts! (>= total-due amount) (err u4))
         (try! (contract-call? .asset transfer amount tx-sender (as-contract tx-sender) none))
-        (map-set loans { owner: tx-sender } { amount: (- total-due amount), last-interaction-block: block-height })
+        (map-set loans tx-sender  { amount: (- total-due amount), last-interaction-block: block-height })
         (var-set total-loans (- (var-get total-loans) amount))
         (ok true)
     )