Added levenshtein.c3 to working files. Fixes to reverse indexing. Added min/max functions. Tentatively removed "opaque"

resources/examples/levenshtein.c3

@@ -0,0 +1,26 @@
+module levenshtein;
+import std::math;
+
+// This levenshtein exercises C3 subarrays.
+fn int levenshtein(char[] s, char[] t)
+{
+    // if either string is empty, difference is inserting all chars
+    // from the other
+    if (!s.len) return t.len;
+    if (!t.len) return s.len;
+
+    // if last letters are the same, the difference is whatever is
+    // required to edit the rest of the strings
+    if (s[^1] == t[^1]) return levenshtein(s[0..^2], t[0..^2]);
+
+    // else try:
+    // changing last letter of s to that of t; or
+    // remove last letter of s; or
+    // remove last letter of t,
+    // any of which is 1 edit plus editing the rest of the strings
+    int a = levenshtein(s[0..^2], t[0..^2]);
+    int b = levenshtein(s, t[0..^2]);
+    int c = levenshtein(s[0..^2], t);
+
+    return @min(@min(a, b), c) + 1;
+}

resources/examples/notworking/levenshtein.c3

@@ -1,24 +0,0 @@
-module levenshtein;
-
-fn int levenshtein(String s, String t)
-{
-    // if either string is empty, difference is inserting all chars
-    // from the other
-    if (!s.len) return t.len;
-    if (!t.len) return s.len;
-
-    // if last letters are the same, the difference is whatever is
-    // required to edit the rest of the strings
-     if (s[^1] == t[^1]) return levenshtein(s[0..^2], t[0..^2]);
-
-     // else try:
-     // changing last letter of s to that of t; or
-     // remove last letter of s; or
-     // remove last letter of t,
-     // any of which is 1 edit plus editing the rest of the strings
-     int a = levenshtein(s[0..^2], t[0..^2]);
-     int b = levenshtein(s, t[0..^2]);
-     int c = levenshtein(s[0..^2], t);
-
-     return @max(@max(a, b), c) + 1;
-}

resources/examples/notworking/toml_parser_c2.c3

@@ -373,7 +373,7 @@ fn void Parser.expect(Parser* p, TokenKind k)
 
 const u32 MaxDiag = 128;
 
-public struct TomlReader @opaque
+public struct TomlReader
 {
     char[MaxDiag] message;
     Blocks* blocks;

resources/lib/std/math.c3

@@ -67,6 +67,16 @@ const QUAD_MIN_EXP = -16481;
 const QUAD_EPSILON = 1.92592994438723585305597794258492732e-34;
 */
 
+macro max(x, y) @autoimport
+{
+    return x > y ? x : y;
+}
+
+macro min(x, y) @autoimport
+{
+    return x < y ? x : y;
+}
+
 fn double log10(double x) @inline
 {
     return $$log10(x);

resources/testfragments/bigint.c3

@@ -6,7 +6,7 @@ macro max(a, b)
 }
 
 // Horribly bad implementation of BigInt with add/sub.
-public struct BigInt @opaque
+public struct BigInt
 {
 	byte* number;
 	uint length;

resources/testfragments/compilertest2.c3

@@ -6,7 +6,7 @@ macro @max(a, b)
 }
 
 // Horribly bad implementation of BigInt with add/sub.
-public struct BigInt @opaque
+public struct BigInt
 {
 	byte& number;
 	uint length;