Merge pull request #191 from chrboesch/dev_1711

dev.1711 - switched to multi-object-for-loops

exercises/016_for2.zig

@@ -1,8 +1,9 @@
 //
-// For loops also let you store the "index" of the iteration - a
-// number starting with 0 that counts up with each iteration:
+// For loops also let you use the "index" of the iteration, a number
+// that counts up with each iteration. To access the index of iteration,
+// specify a second condition as well as a second capture value.
 //
-//     for (items) |item, index| {
+//     for (items, 0..) |item, index| {
 //
 //         // Do something with item and index
 //
@@ -23,8 +24,8 @@ pub fn main() void {
     // Now we'll convert the binary bits to a number value by adding
     // the value of the place as a power of two for each bit.
     //
-    // See if you can figure out the missing piece:
-    for (bits) |bit, ???| {
+    // See if you can figure out the missing pieces:
+    for (bits, ???) |bit, ???| {
         // Note that we convert the usize i to a u32 with
         // @intCast(), a builtin function just like @import().
         // We'll learn about these properly in a later exercise.

exercises/038_structs2.zig

@@ -44,7 +44,7 @@ pub fn main() void {
     // it do and why?
 
     // Printing all RPG characters in a loop:
-    for (chars) |c, num| {
+    for (chars, 0..) |c, num| {
         std.debug.print("Character {} - G:{} H:{} XP:{}\n", .{
             num + 1, c.gold, c.health, c.experience,
         });

exercises/047_methods.zig

@@ -86,7 +86,7 @@ pub fn main() void {
         aliens_alive = 0;
 
         // Loop through every alien by reference (* makes a pointer capture value)
-        for (aliens) |*alien| {
+        for (&aliens) |*alien| {
 
             // *** Zap the alien with the heat ray here! ***
             ???.zap(???);

exercises/058_quiz7.zig

@@ -239,7 +239,7 @@ const HermitsNotebook = struct {
     // We'll often want to find an entry by Place. If one is not
     // found, we return null.
     fn getEntry(self: *HermitsNotebook, place: *const Place) ?*NotebookEntry {
-        for (self.entries) |*entry, i| {
+        for (&self.entries, 0..) |*entry, i| {
             if (i >= self.end_of_entries) break;
 
             // Here's where the hermit got stuck. We need to return

exercises/063_labels.zig

@@ -106,7 +106,7 @@ pub fn main() void {
     const meal = food_loop: for (menu) |food| {
 
         // Now look at each required ingredient for the Food...
-        for (food.requires) |required, required_ingredient| {
+        for (food.requires, 0..) |required, required_ingredient| {
 
             // This ingredient isn't required, so skip it.
             if (!required) continue;

exercises/075_quiz8.zig

@@ -102,7 +102,7 @@ const HermitsNotebook = struct {
     end_of_entries: u8 = 0,
 
     fn getEntry(self: *HermitsNotebook, place: *const Place) ?*NotebookEntry {
-        for (self.entries) |*entry, i| {
+        for (&self.entries, 0..) |*entry, i| {
             if (i >= self.end_of_entries) break;
             if (place == entry.*.?.place) return &entry.*.?;
         }