Add horner-eval

chapter2/accumulate.scm

@@ -0,0 +1,7 @@
+;;; accumulate function taking a "sequence" list
+
+(define (accumulate op initial sequence)
+  (if (null? sequence)
+      initial
+      (op (car sequence)
+          (accumulate op initial (cdr sequence)))))

chapter2/horner-eval.scm

@@ -0,0 +1,10 @@
+;;; evaluates a polynomial at x using horner algorithm
+
+(load "accumulate.scm")
+
+(define (horner-eval x coefficient-sequence)
+    (+ (car coefficient-sequence) (accumulate (lambda (this-coeff higher-terms) (* (+ this-coeff higher-terms) x))
+          0
+          (cdr coefficient-sequence))))
+
+(display (horner-eval 2 (list 1 3 0 5 0 1)))