Initial data commit

Task/Fibonacci-sequence/GFA-Basic/fibonacci-sequence.basic

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+'
+' Compute nth Fibonacci number
+'
+' open a window for display
+OPENW 1
+CLEARW 1
+' Display some fibonacci numbers
+' Fib(46) is the largest number GFA Basic can reach
+' (long integers are 4 bytes)
+FOR i%=0 TO 46
+  PRINT "fib(";i%;")=";@fib(i%)
+NEXT i%
+' wait for a key press and tidy up
+~INP(2)
+CLOSEW 1
+'
+' Function to compute nth fibonacci number
+' n must be in range 0 to 46, inclusive
+'
+FUNCTION fib(n%)
+  LOCAL n0%,n1%,nn%,i%
+  n0%=0
+  n1%=1
+  SELECT n%
+  CASE 0
+    RETURN n0%
+  CASE 1
+    RETURN n1%
+  DEFAULT
+    FOR i%=2 TO n%
+      nn%=n0%+n1%
+      n0%=n1%
+      n1%=nn%
+    NEXT i%
+    RETURN nn%
+  ENDSELECT
+ENDFUNC