Add core:text/regex

core/text/regex/common/common.odin

@@ -0,0 +1,27 @@
+// This package helps break dependency cycles.
+package regex_common
+
+// VM limitations
+MAX_CAPTURE_GROUPS :: 10
+MAX_PROGRAM_SIZE   :: int(max(i16))
+MAX_CLASSES        :: int(max(u8))
+
+Flag :: enum u8 {
+	// Global: try to match the pattern anywhere in the string.
+	Global,
+	// Multiline: treat `^` and `$` as if they also match newlines.
+	Multiline,
+	// Case Insensitive: treat `a-z` as if it was also `A-Z`.
+	Case_Insensitive,
+	// Ignore Whitespace: bypass unescaped whitespace outside of classes.
+	Ignore_Whitespace,
+	// Unicode: let the compiler and virtual machine know to expect Unicode strings.
+	Unicode,
+
+	// No Capture: avoid saving capture group data entirely.
+	No_Capture,
+	// No Optimization: do not pass the pattern through the optimizer; for debugging.
+	No_Optimization,
+}
+
+Flags :: bit_set[Flag; u8]