Core library clean up: Make range expressions more consistent and replace uses of `..` with `..=`

23 files changed, 80 insertions, 84 deletions

diff --git a/core/bytes/bytes.odin b/core/bytes/bytes.odin
index b3d332c67..a7cf23d1b 100644
--- a/core/bytes/bytes.odin
+++ b/core/bytes/bytes.odin
@@ -91,7 +91,7 @@ equal_fold :: proc(u, v: []byte) -> bool {
 
 		if tr < utf8.RUNE_SELF {
 			switch sr {
-			case 'A'..'Z':
+			case 'A'..='Z':
 				if tr == (sr+'a')-'A' {
 					continue loop;
 				}
diff --git a/core/c/frontend/preprocessor/preprocess.odin b/core/c/frontend/preprocessor/preprocess.odin
index 767bb89b3..2136c19ba 100644
--- a/core/c/frontend/preprocessor/preprocess.odin
+++ b/core/c/frontend/preprocessor/preprocess.odin
@@ -139,18 +139,18 @@ append_token :: proc(a, b: ^Token) -> ^Token {
 
 is_hex_digit :: proc(x: byte) -> bool {
 	switch x {
-	case '0'..'9', 'a'..'f', 'A'..'F':
+	case '0'..='9', 'a'..='f', 'A'..='F':
 		return true;
 	}
 	return false;
 }
 from_hex :: proc(x: byte) -> i32 {
 	switch x {
-	case '0'..'9':
+	case '0'..='9':
 		return i32(x) - '0';
-	case 'a'..'f':
+	case 'a'..='f':
 		return i32(x) - 'a' + 10;
-	case 'A'..'F':
+	case 'A'..='F':
 		return i32(x) - 'A' + 10;
 	}
 	return 16;
diff --git a/core/c/frontend/preprocessor/unquote.odin b/core/c/frontend/preprocessor/unquote.odin
index 4aa4926e7..a72a3601c 100644
--- a/core/c/frontend/preprocessor/unquote.odin
+++ b/core/c/frontend/preprocessor/unquote.odin
@@ -5,9 +5,9 @@ import "core:unicode/utf8"
 unquote_char :: proc(str: string, quote: byte) -> (r: rune, multiple_bytes: bool, tail_string: string, success: bool) {
 	hex_to_int :: proc(c: byte) -> int {
 		switch c {
-		case '0'..'9': return int(c-'0');
-		case 'a'..'f': return int(c-'a')+10;
-		case 'A'..'F': return int(c-'A')+10;
+		case '0'..='9': return int(c-'0');
+		case 'a'..='f': return int(c-'a')+10;
+		case 'A'..='F': return int(c-'A')+10;
 		}
 		return -1;
 	}
@@ -45,7 +45,7 @@ unquote_char :: proc(str: string, quote: byte) -> (r: rune, multiple_bytes: bool
 	case '"':  r = '"';
 	case '\'': r = '\'';
 
-	case '0'..'7':
+	case '0'..='7':
 		v := int(c-'0');
 		if len(s) < 2 {
 			return;
diff --git a/core/c/frontend/tokenizer/tokenizer.odin b/core/c/frontend/tokenizer/tokenizer.odin
index 254806cf4..8a3747434 100644
--- a/core/c/frontend/tokenizer/tokenizer.odin
+++ b/core/c/frontend/tokenizer/tokenizer.odin
@@ -224,11 +224,11 @@ scan_string :: proc(t: ^Tokenizer) -> string {
 
 digit_val :: proc(r: rune) -> int {
 	switch r {
-	case '0'..'9':
+	case '0'..='9':
 		return int(r-'0');
-	case 'A'..'F':
+	case 'A'..='F':
 		return int(r-'A' + 10);
-	case 'a'..'f':
+	case 'a'..='f':
 		return int(r-'a' + 10);
 	}
 	return 16;
@@ -245,7 +245,7 @@ scan_escape :: proc(t: ^Tokenizer) -> bool {
 		advance_rune(t);
 		return true;
 
-	case '0'..'7':
+	case '0'..='7':
 		for digit_val(t.ch) < 8 {
 			advance_rune(t);
 		}
diff --git a/core/compress/gzip/gzip.odin b/core/compress/gzip/gzip.odin
index 2b5e513c7..82488a5a8 100644
--- a/core/compress/gzip/gzip.odin
+++ b/core/compress/gzip/gzip.odin
@@ -288,11 +288,11 @@ load_from_stream :: proc(stream: io.Stream, buf: ^bytes.Buffer, allocator := con
 
 	payload_crc_b: [4]u8;
 	payload_len_b: [4]u8;
-	for i in 0..3 {
+	for _, i in payload_crc_b {
 		payload_crc_b[i] = u8(compress.read_bits_lsb(&ctx, 8));
 	}
 	payload_crc := transmute(u32le)payload_crc_b;
-	for i in 0..3 {
+	for _, i in payload_len_b {
 		payload_len_b[i] = u8(compress.read_bits_lsb(&ctx, 8));
 	}
 	payload_len := int(transmute(u32le)payload_len_b);
diff --git a/core/compress/zlib/zlib.odin b/core/compress/zlib/zlib.odin
index bc19c37ef..779122c1e 100644
--- a/core/compress/zlib/zlib.odin
+++ b/core/compress/zlib/zlib.odin
@@ -133,9 +133,7 @@ write_byte :: #force_inline proc(z: ^Context, c: u8) -> (err: io.Error) #no_boun
 }
 
 allocate_huffman_table :: proc(allocator := context.allocator) -> (z: ^Huffman_Table, err: Error) {
-
-	z = new(Huffman_Table, allocator);
-	return z, nil;
+	return new(Huffman_Table, allocator), nil;
 }
 
 build_huffman :: proc(z: ^Huffman_Table, code_lengths: []u8) -> (err: Error) {
@@ -152,14 +150,14 @@ build_huffman :: proc(z: ^Huffman_Table, code_lengths: []u8) -> (err: Error) {
 	}
 	sizes[0] = 0;
 
-	for i in 1..16 {
+	for i in 1..<(HUFFMAN_MAX_BITS+1) {
 		if sizes[i] > (1 << uint(i)) {
 			return E_Deflate.Huffman_Bad_Sizes;
 		}
 	}
 	code := int(0);
 
-	for i in 1..<16 {
+	for i in 1..<HUFFMAN_MAX_BITS {
 		next_code[i]     = code;
 		z.firstcode[i]   = u16(code);
 		z.firstsymbol[i] = u16(k);
@@ -169,12 +167,12 @@ build_huffman :: proc(z: ^Huffman_Table, code_lengths: []u8) -> (err: Error) {
 				return E_Deflate.Huffman_Bad_Code_Lengths;
 			}
 		}
-		z.maxcode[i] = code << (16 - uint(i));
+		z.maxcode[i] = code << (HUFFMAN_MAX_BITS - uint(i));
 		code <<= 1;
 		k += int(sizes[i]);
 	}
 
-	z.maxcode[16] = 0x10000; // Sentinel
+	z.maxcode[HUFFMAN_MAX_BITS] = 0x10000; // Sentinel
 	c: int;
 
 	for v, ci in code_lengths {
@@ -197,7 +195,6 @@ build_huffman :: proc(z: ^Huffman_Table, code_lengths: []u8) -> (err: Error) {
 }
 
 decode_huffman_slowpath :: proc(z: ^Context, t: ^Huffman_Table) -> (r: u16, err: Error) #no_bounds_check {
-
 	r   = 0;
 	err = nil;
 
@@ -233,7 +230,6 @@ decode_huffman_slowpath :: proc(z: ^Context, t: ^Huffman_Table) -> (r: u16, err:
 }
 
 decode_huffman :: proc(z: ^Context, t: ^Huffman_Table) -> (r: u16, err: Error) #no_bounds_check {
-
 	if z.num_bits < 16 {
 		if z.num_bits == -100 {
 			return 0, E_ZLIB.Code_Buffer_Malformed;
diff --git a/core/encoding/cel/cel.odin b/core/encoding/cel/cel.odin
index f0cd49866..94f9281b3 100644
--- a/core/encoding/cel/cel.odin
+++ b/core/encoding/cel/cel.odin
@@ -201,9 +201,9 @@ next_token :: proc(p: ^Parser) -> Token {
 unquote_char :: proc(str: string, quote: byte) -> (r: rune, multiple_bytes: bool, tail_string: string, success: bool) {
 	hex_to_int :: proc(c: byte) -> int {
 		switch c {
-		case '0'..'9': return int(c-'0');
-		case 'a'..'f': return int(c-'a')+10;
-		case 'A'..'F': return int(c-'A')+10;
+		case '0'..='9': return int(c-'0');
+		case 'a'..='f': return int(c-'a')+10;
+		case 'A'..='F': return int(c-'A')+10;
 		}
 		return -1;
 	}
@@ -241,7 +241,7 @@ unquote_char :: proc(str: string, quote: byte) -> (r: rune, multiple_bytes: bool
 	case '"':  r = '"';
 	case '\'': r = '\'';
 
-	case '0'..'7':
+	case '0'..='7':
 		v := int(c-'0');
 		if len(s) < 2 {
 			return;
diff --git a/core/encoding/cel/token.odin b/core/encoding/cel/token.odin
index 7cd9e7c12..4d6b9473c 100644
--- a/core/encoding/cel/token.odin
+++ b/core/encoding/cel/token.odin
@@ -232,7 +232,7 @@ get_pos :: proc(t: ^Tokenizer) -> Pos {
 
 is_letter :: proc(r: rune) -> bool {
 	switch r {
-	case 'a'..'z', 'A'..'Z', '_':
+	case 'a'..='z', 'A'..='Z', '_':
 		return true;
 	}
 	return false;
@@ -240,7 +240,7 @@ is_letter :: proc(r: rune) -> bool {
 
 is_digit :: proc(r: rune) -> bool {
 	switch r {
-	case '0'..'9':
+	case '0'..='9':
 		return true;
 	}
 	return false;
@@ -273,9 +273,9 @@ scan_identifier :: proc(t: ^Tokenizer) -> string {
 
 digit_value :: proc(r: rune) -> int {
 	switch r {
-	case '0'..'9': return int(r - '0');
-	case 'a'..'f': return int(r - 'a' + 10);
-	case 'A'..'F': return int(r - 'A' + 10);
+	case '0'..='9': return int(r - '0');
+	case 'a'..='f': return int(r - 'a' + 10);
+	case 'A'..='F': return int(r - 'A' + 10);
 	}
 	return 16;
 }
diff --git a/core/encoding/json/parser.odin b/core/encoding/json/parser.odin
index 448a0e41f..54cf9b6ef 100644
--- a/core/encoding/json/parser.odin
+++ b/core/encoding/json/parser.odin
@@ -290,9 +290,9 @@ unquote_string :: proc(token: Token, spec: Specification, allocator := context.a
 		for c in s[2:4] {
 			x: rune;
 			switch c {
-			case '0'..'9': x = c - '0';
-			case 'a'..'f': x = c - 'a' + 10;
-			case 'A'..'F': x = c - 'A' + 10;
+			case '0'..='9': x = c - '0';
+			case 'a'..='f': x = c - 'a' + 10;
+			case 'A'..='F': x = c - 'A' + 10;
 			case: return -1;
 			}
 			r = r*16 + x;
@@ -308,9 +308,9 @@ unquote_string :: proc(token: Token, spec: Specification, allocator := context.a
 		for c in s[2:6] {
 			x: rune;
 			switch c {
-			case '0'..'9': x = c - '0';
-			case 'a'..'f': x = c - 'a' + 10;
-			case 'A'..'F': x = c - 'A' + 10;
+			case '0'..='9': x = c - '0';
+			case 'a'..='f': x = c - 'a' + 10;
+			case 'A'..='F': x = c - 'A' + 10;
 			case: return -1;
 			}
 			r = r*16 + x;
diff --git a/core/encoding/json/tokenizer.odin b/core/encoding/json/tokenizer.odin
index b3860d428..df12ce0b6 100644
--- a/core/encoding/json/tokenizer.odin
+++ b/core/encoding/json/tokenizer.odin
@@ -82,7 +82,7 @@ get_token :: proc(t: ^Tokenizer) -> (token: Token, err: Error) {
 		for t.offset < len(t.data) {
 			next_rune(t);
 			switch t.r {
-			case '0'..'9', 'a'..'f', 'A'..'F':
+			case '0'..='9', 'a'..='f', 'A'..='F':
 				// Okay
 			case:
 				return;
@@ -100,7 +100,7 @@ get_token :: proc(t: ^Tokenizer) -> (token: Token, err: Error) {
 			for i := 0; i < 4; i += 1 {
 				r := next_rune(t);
 				switch r {
-				case '0'..'9', 'a'..'f', 'A'..'F':
+				case '0'..='9', 'a'..='f', 'A'..='F':
 					// Okay
 				case:
 					return false;
@@ -149,7 +149,7 @@ get_token :: proc(t: ^Tokenizer) -> (token: Token, err: Error) {
 	skip_alphanum :: proc(t: ^Tokenizer) {
 		for t.offset < len(t.data) {
 			switch next_rune(t) {
-			case 'A'..'Z', 'a'..'z', '0'..'9', '_':
+			case 'A'..='Z', 'a'..='z', '0'..='9', '_':
 				continue;
 			}
 
@@ -173,7 +173,7 @@ get_token :: proc(t: ^Tokenizer) -> (token: Token, err: Error) {
 		token.kind = .EOF;
 		err = .EOF;
 
-	case 'A'..'Z', 'a'..'z', '_':
+	case 'A'..='Z', 'a'..='z', '_':
 		token.kind = .Ident;
 
 		skip_alphanum(t);
@@ -200,7 +200,7 @@ get_token :: proc(t: ^Tokenizer) -> (token: Token, err: Error) {
 
 	case '-':
 		switch t.r {
-		case '0'..'9':
+		case '0'..='9':
 			// Okay
 		case:
 			// Illegal use of +/-
@@ -219,7 +219,7 @@ get_token :: proc(t: ^Tokenizer) -> (token: Token, err: Error) {
 		}
 		fallthrough;
 
-	case '0'..'9':
+	case '0'..='9':
 		token.kind = t.parse_integers ? .Integer : .Float;
 		if t.spec == .JSON5 { // Hexadecimal Numbers
 			if curr_rune == '0' && (t.r == 'x' || t.r == 'X') {
@@ -361,7 +361,7 @@ is_valid_number :: proc(str: string, spec: Specification) -> bool {
 	switch s[0] {
 	case '0':
 		s = s[1:];
-	case '1'..'9':
+	case '1'..='9':
 		s = s[1:];
 		for len(s) > 0 && '0' <= s[0] && s[0] <= '9' {
 			s = s[1:];
@@ -453,7 +453,7 @@ is_valid_string_literal :: proc(str: string, spec: Specification) -> bool {
 				for j := 0; j < 4; j += 1 {
 					c2 := hex[j];
 					switch c2 {
-					case '0'..'9', 'a'..'z', 'A'..'Z':
+					case '0'..='9', 'a'..='z', 'A'..='Z':
 						// Okay
 					case:
 						return false;
diff --git a/core/image/png/png.odin b/core/image/png/png.odin
index 7762f0106..642b30a26 100644
--- a/core/image/png/png.odin
+++ b/core/image/png/png.odin
@@ -1348,31 +1348,31 @@ defilter_less_than_8 :: proc(params: ^Filter_Params) -> (ok: bool) #no_bounds_ch
 		case .None:
 			copy(dest, src[:row_stride_in]);
 		case .Sub:
-			for i in 0..channels {
+			for i in 0..=channels {
 				dest[i] = src[i];
 			}
-			for k in 0..nk {
+			for k in 0..=nk {
 				dest[channels+k] = (src[channels+k] + dest[k]) & 255;
 			}
 		case .Up:
-			for k in 0..row_stride_in {
+			for k in 0..=row_stride_in {
 				dest[k] = (src[k] + up[k]) & 255;
 			}
 		case .Average:
-			for i in 0..channels {
+			for i in 0..=channels {
 				avg := up[i] >> 1;
 				dest[i] = (src[i] + avg) & 255;
 			}
-			for k in 0..nk {
+			for k in 0..=nk {
 				avg := u8((u16(up[channels+k]) + u16(dest[k])) >> 1);
 				dest[channels+k] = (src[channels+k] + avg) & 255;
 			}
 		case .Paeth:
-			for i in 0..channels {
+			for i in 0..=channels {
 				paeth := filter_paeth(0, up[i], 0);
 				dest[i] = (src[i] + paeth) & 255;
 			}
-			for k in 0..nk {
+			for k in 0..=nk {
 				paeth := filter_paeth(dest[k], up[channels+k], up[k]);
 				dest[channels+k] = (src[channels+k] + paeth) & 255;
 			}
@@ -1380,9 +1380,9 @@ defilter_less_than_8 :: proc(params: ^Filter_Params) -> (ok: bool) #no_bounds_ch
 			return false;
 		}
 
-		src   = src [row_stride_in:];
-		up    = dest;
-		dest  = dest[row_stride_in:];
+		src  = src[row_stride_in:];
+		up   = dest;
+		dest = dest[row_stride_in:];
 	}
 
 	// Let's expand the bits
diff --git a/core/os/file_windows.odin b/core/os/file_windows.odin
index 8b99ee9ee..9e22c96a2 100644
--- a/core/os/file_windows.odin
+++ b/core/os/file_windows.odin
@@ -347,7 +347,7 @@ is_abs :: proc(path: string) -> bool {
 	when ODIN_OS == "windows" {
 		if len(path) > 2 {
 			switch path[0] {
-			case 'A'..'Z', 'a'..'z':
+			case 'A'..='Z', 'a'..='z':
 				return path[1] == ':' && is_path_separator(path[2]);
 			}
 		}
diff --git a/core/os/os2/stat_windows.odin b/core/os/os2/stat_windows.odin
index 48811340a..0b6834fe0 100644
--- a/core/os/os2/stat_windows.odin
+++ b/core/os/os2/stat_windows.odin
@@ -322,7 +322,7 @@ _is_abs :: proc(path: string) -> bool {
 	}
 	if len(path) > 2 {
 		switch path[0] {
-		case 'A'..'Z', 'a'..'z':
+		case 'A'..='Z', 'a'..='z':
 			return path[1] == ':' && is_path_separator(path[2]);
 		}
 	}
diff --git a/core/path/filepath/path.odin b/core/path/filepath/path.odin
index 33ea5541c..7dd7484f0 100644
--- a/core/path/filepath/path.odin
+++ b/core/path/filepath/path.odin
@@ -39,7 +39,7 @@ volume_name_len :: proc(path: string) -> int {
 		c := path[0];
 		if path[1] == ':' {
 			switch c {
-			case 'a'..'z', 'A'..'Z':
+			case 'a'..='z', 'A'..='Z':
 				return 2;
 			}
 		}
diff --git a/core/strconv/strconv.odin b/core/strconv/strconv.odin
index 21a29b243..ca8934aa9 100644
--- a/core/strconv/strconv.odin
+++ b/core/strconv/strconv.odin
@@ -16,9 +16,9 @@ _digit_value :: proc(r: rune) -> int {
 	ri := int(r);
 	v: int = 16;
 	switch r {
-	case '0'..'9': v = ri-'0';
-	case 'a'..'z': v = ri-'a'+10;
-	case 'A'..'Z': v = ri-'A'+10;
+	case '0'..='9': v = ri-'0';
+	case 'a'..='z': v = ri-'a'+10;
+	case 'A'..='Z': v = ri-'A'+10;
 	}
 	return v;
 }
@@ -557,9 +557,9 @@ quote_rune :: proc(buf: []byte, r: rune) -> string {
 unquote_char :: proc(str: string, quote: byte) -> (r: rune, multiple_bytes: bool, tail_string: string, success: bool) {
 	hex_to_int :: proc(c: byte) -> int {
 		switch c {
-		case '0'..'9': return int(c-'0');
-		case 'a'..'f': return int(c-'a')+10;
-		case 'A'..'F': return int(c-'A')+10;
+		case '0'..='9': return int(c-'0');
+		case 'a'..='f': return int(c-'a')+10;
+		case 'A'..='F': return int(c-'A')+10;
 		}
 		return -1;
 	}
@@ -597,7 +597,7 @@ unquote_char :: proc(str: string, quote: byte) -> (r: rune, multiple_bytes: bool
 	case '"':  r = '"';
 	case '\'': r = '\'';
 
-	case '0'..'7':
+	case '0'..='7':
 		v := int(c-'0');
 		if len(s) < 2 {
 			return;
diff --git a/core/strings/builder.odin b/core/strings/builder.odin
index 843f79381..f2926b969 100644
--- a/core/strings/builder.odin
+++ b/core/strings/builder.odin
@@ -314,9 +314,9 @@ write_escaped_rune_writer :: proc(w: io.Writer, r: rune, quote: byte, html_safe
 	is_printable :: proc(r: rune) -> bool {
 		if r <= 0xff {
 			switch r {
-			case 0x20..0x7e:
+			case 0x20..=0x7e:
 				return true;
-			case 0xa1..0xff: // ¡ through ÿ except for the soft hyphen
+			case 0xa1..=0xff: // ¡ through ÿ except for the soft hyphen
 				return r != 0xad; //
 			}
 		}
diff --git a/core/strings/conversion.odin b/core/strings/conversion.odin
index c03bed86a..26535f8c0 100644
--- a/core/strings/conversion.odin
+++ b/core/strings/conversion.odin
@@ -85,9 +85,9 @@ is_delimiter :: proc(c: rune) -> bool {
 is_separator :: proc(r: rune) -> bool {
 	if r <= 0x7f {
 		switch r {
-		case '0'..'9': return false;
-		case 'a'..'z': return false;
-		case 'A'..'Z': return false;
+		case '0'..='9': return false;
+		case 'a'..='z': return false;
+		case 'A'..='Z': return false;
 		case '_': return false;
 		}
 		return true;
diff --git a/core/strings/strings.odin b/core/strings/strings.odin
index 5537822a8..e81b41222 100644
--- a/core/strings/strings.odin
+++ b/core/strings/strings.odin
@@ -104,7 +104,7 @@ equal_fold :: proc(u, v: string) -> bool {
 
 		if tr < utf8.RUNE_SELF {
 			switch sr {
-			case 'A'..'Z':
+			case 'A'..='Z':
 				if tr == (sr+'a')-'A' {
 					continue loop;
 				}
diff --git a/core/sync/sync_darwin.odin b/core/sync/sync_darwin.odin
index c8e9632be..0fd2fc2a7 100644
--- a/core/sync/sync_darwin.odin
+++ b/core/sync/sync_darwin.odin
@@ -42,7 +42,7 @@ semaphore_destroy :: proc(s: ^Semaphore) {
 
 semaphore_post :: proc(s: ^Semaphore, count := 1) {
 	// NOTE: SPEED: If there's one syscall to do this, we should use it instead of the loop.
-	for in 0..count-1 {
+	for in 0..<count {
 		res := darwin.semaphore_signal(s.handle);
 		assert(res == 0);
 	}
diff --git a/core/sync/sync_freebsd.odin b/core/sync/sync_freebsd.odin
index 87532621d..0fa5f9e6f 100644
--- a/core/sync/sync_freebsd.odin
+++ b/core/sync/sync_freebsd.odin
@@ -33,7 +33,7 @@ semaphore_destroy :: proc(s: ^Semaphore) {
 
 semaphore_post :: proc(s: ^Semaphore, count := 1) {
     // NOTE: SPEED: If there's one syscall to do this, we should use it instead of the loop.
-    for in 0..count-1 {
+    for in 0..<count {
 	    assert(unix.sem_post(&s.handle) == 0);
     }
 }
diff --git a/core/sync/sync_linux.odin b/core/sync/sync_linux.odin
index aa3c7a068..6474cd900 100644
--- a/core/sync/sync_linux.odin
+++ b/core/sync/sync_linux.odin
@@ -33,7 +33,7 @@ semaphore_destroy :: proc(s: ^Semaphore) {
 
 semaphore_post :: proc(s: ^Semaphore, count := 1) {
     // NOTE: SPEED: If there's one syscall to do this, we should use it instead of the loop.
-    for in 0..count-1 {
+    for in 0..<count {
 	    assert(unix.sem_post(&s.handle) == 0);
     }
 }
diff --git a/core/text/scanner/scanner.odin b/core/text/scanner/scanner.odin
index 45c2a5d8f..9520b52df 100644
--- a/core/text/scanner/scanner.odin
+++ b/core/text/scanner/scanner.odin
@@ -421,8 +421,8 @@ scan_number :: proc(s: ^Scanner, ch: rune, seen_dot: bool) -> (rune, rune) {
 scan_string :: proc(s: ^Scanner, quote: rune) -> (n: int) {
 	digit_val :: proc(ch: rune) -> int {
 		switch v := lower(ch); v {
-		case '0'..'9': return int(v - '0');
-		case 'a'..'z': return int(v - 'a');
+		case '0'..='9': return int(v - '0');
+		case 'a'..='z': return int(v - 'a');
 		}
 		return 16;
 	}
@@ -450,10 +450,10 @@ scan_string :: proc(s: ^Scanner, quote: rune) -> (n: int) {
 			switch ch {
 			case quote, 'a', 'b', 'e', 'f', 'n', 'r', 't', 'v', '\\':
 				ch = advance(s);
-			case '0'..'7': ch = scan_digits(s, advance(s), 8, 3);
-			case 'x':      ch = scan_digits(s, advance(s), 16, 2);
-			case 'u':      ch = scan_digits(s, advance(s), 16, 4);
-			case 'U':      ch = scan_digits(s, advance(s), 16, 8);
+			case '0'..='7': ch = scan_digits(s, advance(s), 8, 3);
+			case 'x':       ch = scan_digits(s, advance(s), 16, 2);
+			case 'u':       ch = scan_digits(s, advance(s), 16, 4);
+			case 'U':       ch = scan_digits(s, advance(s), 16, 8);
 			case:
 				error(s, "invalid char escape");
 			}
diff --git a/core/unicode/utf16/utf16.odin b/core/unicode/utf16/utf16.odin
index a436655b4..4c76956cc 100644
--- a/core/unicode/utf16/utf16.odin
+++ b/core/unicode/utf16/utf16.odin
@@ -39,7 +39,7 @@ encode :: proc(d: []u16, s: []rune) -> int {
 			d[n] = u16(r);
 			n += 1;
 
-		case _surr_self .. MAX_RUNE:
+		case _surr_self ..= MAX_RUNE:
 			if m+2 < n { break loop; }
 			r1, r2 := encode_surrogate_pair(r);
 			d[n]    = u16(r1);
@@ -65,7 +65,7 @@ encode_string :: proc(d: []u16, s: string) -> int {
 			d[n] = u16(r);
 			n += 1;
 
-		case _surr_self .. MAX_RUNE:
+		case _surr_self ..= MAX_RUNE:
 			if m+2 < n { break loop; }
 			r1, r2 := encode_surrogate_pair(r);
 			d[n]    = u16(r1);