From 30fdfca72ca1277c127c42e86bba2481246db0f7 Mon Sep 17 00:00:00 2001
From: Ekaitz Zarraga <ekaitz@elenq.tech>
Date: Fri, 4 Nov 2022 20:13:29 +0100
Subject: Add state and its representation in states

---
 depre/main.scm | 37 +++++++++++++++++++++++++++++++++----
 1 file changed, 33 insertions(+), 4 deletions(-)

diff --git a/depre/main.scm b/depre/main.scm
index 37a3b35..81bdb03 100644
--- a/depre/main.scm
+++ b/depre/main.scm
@@ -1,8 +1,10 @@
 ; https://xn--rpa.cc/irl/term.html
 (define-module (depre main))
 
-(define %depression 50)
-(define %tiredness  50)
+;; Code makes heavy use of functional code and parameters for state.
+(define max-100 (lambda (x) (if (> x 100) 100 x)))
+(define %depression (make-parameter 50 max-100))
+(define %tiredness  (make-parameter 50 max-100))
 
 (define (nth n lst)
   (if (> n (length lst))
@@ -13,6 +15,8 @@
       (car lst)
       (loop (cdr lst) (- n 1))))))
 
+
+;; Function combinations: they define the state transitions
 (define (combine . functions)
   "Calls given functions in given order."
   (lambda ()
@@ -21,13 +25,36 @@
         ((car fs))
         (loop (cdr fs))))))
 
+;; Simple I/O
 (define (answer message)
   (lambda ()
     (display message)
     (newline)))
 
-(define (state heading menu)
+(define (bar percent)
+  "A simple 12 character bar for life-like variable representation"
+  (define len 22)
+  (string-tabulate
+    (lambda (x)
+      (cond
+        ((= x 0)                          #\[)
+        ((= x (- len 1))                  #\])
+        ((>= (/ percent (/ 100 len)) x)   #\=)
+        (else                             #\space)))
+    len))
+
+
+;; Basic state representation and creation: A state is a function that knows
+;; how to jump to other states through a menu.
+(define* (state heading menu #:optional (hide-status #f))
   (lambda ()
+    (when (not hide-status)
+      (newline)
+      (display "Depression:\t")
+      (display (bar (%depression)))
+      (newline)
+      (display "Tiredness:\t")
+      (display (bar (%tiredness))))
     (newline)
     (display heading)
     (newline)
@@ -43,6 +70,7 @@
           (display "Wrong answer. Try again >  ")
           (loop (read)))))))
 
+;; States:
 (define start
   (state "Hi, game starts"
          (list (cons "Start game"
@@ -52,6 +80,7 @@
                               (list (cons "hola"  (lambda () (display "HOLA")))
                                     (cons "adios" (lambda () (display "adios")))))))
                (cons "Quit game"
-                     (answer "Good bye!")))))
+                     (answer "Good bye!")))
+         #:hide-status))
 
 (start)
-- 
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