From 8f5b838a071d010959a3f38a2c73cf49f31a16cf Mon Sep 17 00:00:00 2001
From: Feoramund <161657516+Feoramund@users.noreply.github.com>
Date: Mon, 5 Aug 2024 03:49:29 -0400
Subject: [PATCH] Review manual `for` loops in `core:text/regex`

---
 core/text/regex/optimizer/optimizer.odin | 8 ++++----
 core/text/regex/parser/parser.odin       | 4 +++-
 core/text/regex/regex.odin               | 2 +-
 3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/core/text/regex/optimizer/optimizer.odin b/core/text/regex/optimizer/optimizer.odin
index 835e5022c..e23cc1bc5 100644
--- a/core/text/regex/optimizer/optimizer.odin
+++ b/core/text/regex/optimizer/optimizer.odin
@@ -86,7 +86,7 @@ optimize_subtree :: proc(tree: Node, flags: common.Flags) -> (result: Node, chan
 		}
 
 		// Only recursive optimizations:
-		for i := 0; i < len(specific.nodes); i += 1 {
+		#no_bounds_check for i := 0; i < len(specific.nodes); i += 1 {
 			subnode, subnode_changes := optimize_subtree(specific.nodes[i], flags)
 			changes += subnode_changes
 			if subnode == nil {
@@ -194,7 +194,7 @@ optimize_subtree :: proc(tree: Node, flags: common.Flags) -> (result: Node, chan
 			new_range.lower = specific.runes[0]
 			new_range.upper = specific.runes[0]
 
-			for i := 1; i < len(specific.runes); i += 1 {
+			#no_bounds_check for i := 1; i < len(specific.runes); i += 1 {
 				r := specific.runes[i]
 				if new_range.lower == -1 {
 					new_range = { r, r }
@@ -228,7 +228,7 @@ optimize_subtree :: proc(tree: Node, flags: common.Flags) -> (result: Node, chan
 		//
 		// DO: `[aa-c]` => `[a-c]`
 		for range in specific.ranges {
-			for i := 0; i < len(specific.runes); i += 1 {
+			#no_bounds_check for i := 0; i < len(specific.runes); i += 1 {
 				r := specific.runes[i]
 				if range.lower <= r && r <= range.upper {
 					ordered_remove(&specific.runes, i)
@@ -244,7 +244,7 @@ optimize_subtree :: proc(tree: Node, flags: common.Flags) -> (result: Node, chan
 		// DO: `[a-cd-e]` => `[a-e]`
 		// DO: `[a-cb-e]` => `[a-e]`
 		slice.sort_by(specific.ranges[:], class_range_sorter)
-		for i := 0; i < len(specific.ranges) - 1; i += 1 {
+		#no_bounds_check for i := 0; i < len(specific.ranges) - 1; i += 1 {
 			for j := i + 1; j < len(specific.ranges); j += 1 {
 				left_range  := &specific.ranges[i]
 				right_range :=  specific.ranges[j]
diff --git a/core/text/regex/parser/parser.odin b/core/text/regex/parser/parser.odin
index 720992cb9..038d4cb85 100644
--- a/core/text/regex/parser/parser.odin
+++ b/core/text/regex/parser/parser.odin
@@ -225,7 +225,7 @@ null_denotation :: proc(p: ^Parser, token: Token) -> (result: Node, err: Error)
 
 		node := new(Node_Rune_Class)
 
-		for i := 0; i < len(token.text); /**/ {
+		#no_bounds_check for i := 0; i < len(token.text); /**/ {
 			r, size := utf8.decode_rune(token.text[i:])
 			if i == 0 && r == '^' {
 				node.negating = true
@@ -298,6 +298,8 @@ null_denotation :: proc(p: ^Parser, token: Token) -> (result: Node, err: Error)
 		}
 
 		if .Case_Insensitive in p.flags {
+			// These two loops cannot be in the form of `for x in y` because
+			// they append to the data that they iterate over.
 			length := len(node.runes)
 			#no_bounds_check for i := 0; i < length; i += 1 {
 				r := node.runes[i]
diff --git a/core/text/regex/regex.odin b/core/text/regex/regex.odin
index 9ff924192..3dc26b5c6 100644
--- a/core/text/regex/regex.odin
+++ b/core/text/regex/regex.odin
@@ -291,7 +291,7 @@ match_and_allocate_capture :: proc(
 		context.allocator = permanent_allocator
 
 		num_groups := 0
-		for i := 0; i < len(saved); i += 2 {
+		#no_bounds_check for i := 0; i < len(saved); i += 2 {
 			a, b := saved[i], saved[i + 1]
 			if a == -1 || b == -1 {
 				continue