basic for loop + examples -> era3

lib/math.ang

@@ -9,7 +9,7 @@ E := 2.718281828459045235360287471352
 #   returned value is x.
 fn absf(x: float) -> float {
     # if the number is negative
-    if x < 0 {
+    if x < 0.0 {
         # negate it so it's positive
         return -x
     }
@@ -26,7 +26,7 @@ fn absi(n: int) -> int {
 }
 
 DERIVE_DX := 0.00000001
-fn derive(f: fn(float) -> float, x: float) float {
+fn derive(f: fn(float) -> float, x: float) -> float {
     return (f(x + DERIVE_DX) - f(x))/DERIVE_DX
 }
 
@@ -35,7 +35,7 @@ fn newtons(f: fn(float) -> float) -> float {
     pg := 0.0
     g := 1.0
 
-    while abs(g - pg) > NEWTONS_ACC {
+    while absf(g - pg) > NEWTONS_ACC {
         pg = g
         g = pg - f(pg) / derive(f, pg)
     }
@@ -53,12 +53,14 @@ fn sqrt(x: float) -> float {
     ng := x
     g := 1.0
 
-    while abs(g - ng) > MAX_SQRT_DX {
+    while absf(g - ng) > MAX_SQRT_DX {
         g = ng
 
         # create new guess
-        ng = (g + x / g) / 2
+        ng = (g + x / g) / 2.0
     }
+
+    g
 }
 
 # floor(x)
@@ -82,7 +84,7 @@ fn round(x: float) -> float {
     f := floor(x)
 
     if x - f > 0.5 {
-        return f + 1
+        return f + 1.0
     }
 
     return f
@@ -93,16 +95,16 @@ fn round(x: float) -> float {
 # n: number; the number to divide by
 #   Return the rest from a division of x by n.
 fn mod(x: float, n: float) -> float {
-    if x == 0 {
-        return 0
+    if x == 0.0 {
+        return 0.0
     }
 
-    if x < 0 {
-        while x + n <= 0 {
+    if x < 0.0 {
+        while x + n <= 0.0 {
             x = x + n
         }
     } else {
-        while x - n >= 0 {
+        while x - n >= 0.0 {
             x = x - n
         }
     }
@@ -123,7 +125,7 @@ fn sm_exp(x: float) -> float {
     x_pow := x
     f := 1.0
 
-    while abs(tot - p_tot) > SM_EXP_ACC {
+    while absf(tot - p_tot) > SM_EXP_ACC {
         p_tot = tot
         t := x_pow / f
         tot = tot + t
@@ -139,18 +141,18 @@ fn sm_exp(x: float) -> float {
 # x: number; any number
 #   Get an approximate value of e raised to the power of x.
 fn exp(x: float) -> float {
-    n := abs(x)
+    n := absf(x)
     tot := 1.0
-    while n >= 1 {
+    while n >= 1.0 {
         tot = tot * E
-        n = n - 1
+        n = n - 1.0
     }
 
     if n > 0.0 {
         tot = tot * sm_exp(n)
     }
 
-    if x < 0 {
+    if x < 0.0 {
         1.0/tot
     } else {
         tot
@@ -166,9 +168,9 @@ fn ln(x: float) -> float {
     pg := 0.0
     g := 1.0
 
-    while abs(pg - g) > LN_ACC {
+    while absf(pg - g) > LN_ACC {
         pg = g
-        g = pg + x / exp(pg) - 1
+        g = pg + x / exp(pg) - 1.0
     }
 
     return g
@@ -194,7 +196,7 @@ fn log(a: float, b: float) -> float {
     pg := 0.0
     g := 1.0
 
-    while abs(g - pg) > LOG_ACC {
+    while absf(g - pg) > LOG_ACC {
         pg = g
         g = pg - 1.0/ln_b - a/(ln_b*pow(b, pg))
     }
@@ -211,7 +213,7 @@ fn sin(x: float) -> float {
     x = mod(x, 2.0*PI)
     if x > PI {
         x = PI - x
-        f = -1
+        f = -1.0
     }
 
     # compute sine with a taylor series mock function of sine (valid between -pi and +pi)
@@ -220,7 +222,7 @@ fn sin(x: float) -> float {
     i := 1.0
     s := -1.0
 
-    while i <= 19 {
+    while i <= 19.0 {
         i = i + 2.0
         l = s * l * x / i / (i-1.0)
 
@@ -235,13 +237,15 @@ fn sin(x: float) -> float {
 # cos(x)
 # x: number; an angle in radians
 #   Get the cosine of an angle (in radians). https://en.wikipedia.org/wiki/Sine_and_cosine
-func cos(x: number) number {
+fn cos(x: float) -> float {
     # todo
+    0.0
 }
 
 # tan(x)
 # x: number; an angle in radians
 #   Get the tangent of an angle. https://en.wikipedia.org/wiki/Tangent
-func tan(x: number) number {
+fn tan(x: float) -> float {
     # todo
+    0.0
 }