diff --git a/core/_preload.odin b/core/_preload.odin
index 9153f2b55..a86eee836 100644
--- a/core/_preload.odin
+++ b/core/_preload.odin
@@ -339,7 +339,7 @@ __bounds_check_error :: proc(file: string, line, column: int, index, count: int)
 	if 0 <= index && index < count {
 		return;
 	}
-	fmt.fprintf(os.stderr, "%s(%d:%d) Index %d is out of bounds range 0..%d\n",
+	fmt.fprintf(os.stderr, "%s(%d:%d) Index %d is out of bounds range 0..<%d\n",
 	            file, line, column, index, count);
 	__debug_trap();
 }
@@ -348,7 +348,7 @@ __slice_expr_error :: proc(file: string, line, column: int, low, high, max: int)
 	if 0 <= low && low <= high && high <= max {
 		return;
 	}
-	fmt.fprintf(os.stderr, "%s(%d:%d) Invalid slice indices: [%d..%d..%d]\n",
+	fmt.fprintf(os.stderr, "%s(%d:%d) Invalid slice indices: [%d..<%d..<%d]\n",
 	            file, line, column, low, high, max);
 	__debug_trap();
 }
@@ -356,7 +356,7 @@ __substring_expr_error :: proc(file: string, line, column: int, low, high: int)
 	if 0 <= low && low <= high {
 		return;
 	}
-	fmt.fprintf(os.stderr, "%s(%d:%d) Invalid substring indices: [%d..%d]\n",
+	fmt.fprintf(os.stderr, "%s(%d:%d) Invalid substring indices: [%d..<%d]\n",
 	            file, line, column, low, high);
 	__debug_trap();
 }
@@ -395,7 +395,7 @@ __mem_copy_non_overlapping :: proc(dst, src: rawptr, len: int) -> rawptr {
 }
 
 __mem_compare :: proc(a, b: ^byte, n: int) -> int {
-	for i in 0..n {
+	for i in 0..<n {
 		match {
 		case (a+i)^ < (b+i)^:
 			return -1;
@@ -602,7 +602,7 @@ __dynamic_map_rehash :: proc(using header: __Map_Header, new_count: int) {
 
 	__dynamic_array_resize(nm_hashes, size_of(int), align_of(int), new_count);
 	__dynamic_array_reserve(^nm.entries, entry_size, entry_align, m.entries.len);
-	for i in 0..new_count {
+	for i in 0..<new_count {
 		nm.hashes[i] = -1;
 	}
 
diff --git a/core/decimal.odin b/core/decimal.odin
index 6d9593895..ae3d5fee9 100644
--- a/core/decimal.odin
+++ b/core/decimal.odin
@@ -22,29 +22,29 @@ decimal_to_string :: proc(buf: []byte, a: ^Decimal) -> string {
 
 	// TODO(bill): make this work with a buffer that's not big enough
 	assert(len(buf) >= n);
-	buf = buf[..n];
+	buf = buf[0..<n];
 
 	if a.count == 0 {
 		buf[0] = '0';
-		return cast(string)buf[0..1];
+		return cast(string)buf[0..<1];
 	}
 
 	w := 0;
 	if a.decimal_point <= 0 {
 		buf[w] = '0'; w++;
 		buf[w] = '.'; w++;
-		w += digit_zero(buf[w .. w-a.decimal_point]);
-		w += copy(buf[w..], a.digits[0..a.count]);
+		w += digit_zero(buf[w ..< w-a.decimal_point]);
+		w += copy(buf[w..], a.digits[0..<a.count]);
 	} else if a.decimal_point < a.count {
-		w += copy(buf[w..], a.digits[0..a.decimal_point]);
+		w += copy(buf[w..], a.digits[0..<a.decimal_point]);
 		buf[w] = '.'; w++;
-		w += copy(buf[w..], a.digits[a.decimal_point .. a.count]);
+		w += copy(buf[w..], a.digits[a.decimal_point ..< a.count]);
 	} else {
-		w += copy(buf[w..], a.digits[0..a.count]);
-		w += digit_zero(buf[w .. w+a.decimal_point-a.count]);
+		w += copy(buf[w..], a.digits[0..<a.count]);
+		w += digit_zero(buf[w ..< w+a.decimal_point-a.count]);
 	}
 
-	return cast(string)buf[0..w];
+	return cast(string)buf[0..<w];
 }
 
 // trim trailing zeros
diff --git a/core/fmt.odin b/core/fmt.odin
index 575925a16..e9ffeea6d 100644
--- a/core/fmt.odin
+++ b/core/fmt.odin
@@ -21,7 +21,7 @@ write_rune :: proc(buf: ^[]byte, r: rune) {
 	}
 
 	b, n := utf8.encode_rune(r);
-	append(buf, ..b[..n]);
+	append(buf, ..b[0..<n]);
 }
 
 Fmt_Info :: struct {
@@ -47,24 +47,24 @@ Fmt_Info :: struct {
 
 fprint :: proc(fd: os.Handle, args: ..any) -> int {
 	data: [_BUFFER_SIZE]byte;
-	buf := data[..0];
+	buf := data[0..<0];
 	bprint(^buf, ..args);
-	os.write(fd, buf[..len(buf)]);
+	os.write(fd, buf);
 	return len(buf);
 }
 
 fprintln :: proc(fd: os.Handle, args: ..any) -> int {
 	data: [_BUFFER_SIZE]byte;
-	buf := data[..0];
+	buf := data[0..<0];
 	bprintln(^buf, ..args);
-	os.write(fd, buf[..len(buf)]);
+	os.write(fd, buf);
 	return len(buf);
 }
 fprintf :: proc(fd: os.Handle, fmt: string, args: ..any) -> int {
 	data: [_BUFFER_SIZE]byte;
-	buf := data[..0];
+	buf := data[0..<0];
 	bprintf(^buf, fmt, ..args);
-	os.write(fd, buf[..len(buf)]);
+	os.write(fd, buf);
 	return len(buf);
 }
 
@@ -82,9 +82,9 @@ printf :: proc(fmt: string, args: ..any) -> int {
 
 fprint_type :: proc(fd: os.Handle, info: ^Type_Info) {
 	data: [_BUFFER_SIZE]byte;
-	buf := data[..0];
+	buf := data[0..<0];
 	write_type(^buf, info);
-	os.write(fd, buf[..len(buf)]);
+	os.write(fd, buf);
 }
 
 write_type :: proc(buf: ^[]byte, ti: ^Type_Info) {
@@ -305,15 +305,15 @@ bprintln :: proc(buf: ^[]byte, args: ..any) -> int {
 
 sprint :: proc(buf: []byte, args: ..any) -> string {
 	count := bprint(^buf, ..args);
-	return cast(string)buf[..count];
+	return cast(string)buf[0..<count];
 }
 sprintln :: proc(buf: []byte, args: ..any) -> string {
 	count := bprintln(^buf, ..args);
-	return cast(string)buf[..count];
+	return cast(string)buf[0..<count];
 }
 sprintf :: proc(buf: []byte, fmt: string, args: ..any) -> string {
 	count := bprintf(^buf, fmt, ..args);
-	return cast(string)buf[..count];
+	return cast(string)buf[0..<count];
 }
 
 
@@ -519,7 +519,7 @@ _write_int :: proc(fi: ^Fmt_Info, u: u64, base: int, is_signed: bool, bit_size:
 	if fi.hash   { flags |= strconv.Int_Flag.PREFIX; }
 	if fi.plus   { flags |= strconv.Int_Flag.PLUS; }
 	if fi.space  { flags |= strconv.Int_Flag.SPACE; }
-	s := strconv.append_bits(buf[..0], u, base, is_signed, bit_size, digits, flags);
+	s := strconv.append_bits(buf[0..<0], u, base, is_signed, bit_size, digits, flags);
 
 	prev_zero := fi.zero;
 	defer fi.zero = prev_zero;
@@ -584,8 +584,8 @@ fmt_float :: proc(fi: ^Fmt_Info, v: f64, bit_size: int, verb: rune) {
 			prec = fi.prec;
 		}
 		buf: [128]byte;
-		str := strconv.append_float(buf[1..1], v, 'f', prec, bit_size);
-		str = cast(string)buf[..len(str)+1];
+		str := strconv.append_float(buf[1..<1], v, 'f', prec, bit_size);
+		str = cast(string)buf[0..<len(str)];
 		if str[1] == '+' || str[1] == '-' {
 			str = str[1..];
 		} else {
@@ -605,7 +605,7 @@ fmt_float :: proc(fi: ^Fmt_Info, v: f64, bit_size: int, verb: rune) {
 			if fi.zero && fi.width_set && fi.width > len(str) {
 				write_byte(fi.buf, str[0]);
 				fmt_write_padding(fi, fi.width - len(str));
-				write_string(fi.buf, str[1..]);
+				write_string(fi.buf, str[1..<]);
 			} else {
 				_pad(fi, str);
 			}
@@ -628,7 +628,7 @@ fmt_string :: proc(fi: ^Fmt_Info, s: string, verb: rune) {
 		fi.space = false;
 		defer fi.space = space;
 
-		for i in 0..len(s) {
+		for i in 0..<len(s) {
 			if i > 0 && space {
 				write_byte(fi.buf, ' ');
 			}
@@ -776,7 +776,7 @@ fmt_value :: proc(fi: ^Fmt_Info, v: any, verb: rune) {
 
 		write_byte(fi.buf, '[');
 		defer write_byte(fi.buf, ']');
-		for i in 0..info.count {
+		for i in 0..<info.count {
 			if i > 0 {
 				write_string(fi.buf, ", ");
 			}
@@ -793,7 +793,7 @@ fmt_value :: proc(fi: ^Fmt_Info, v: any, verb: rune) {
 		write_byte(fi.buf, '[');
 		defer write_byte(fi.buf, ']');
 		array := cast(^raw.Dynamic_Array)v.data;
-		for i in 0..array.len {
+		for i in 0..<array.len {
 			if i > 0 {
 				write_string(fi.buf, ", ");
 			}
@@ -815,7 +815,7 @@ fmt_value :: proc(fi: ^Fmt_Info, v: any, verb: rune) {
 
 		entry_type := union_cast(^Struct)ed.elem;
 		entry_size := ed.elem_size;
-		for i in 0..entries.len {
+		for i in 0..<entries.len {
 			if i > 0 {
 				write_string(fi.buf, ", ");
 			}
@@ -844,7 +844,7 @@ fmt_value :: proc(fi: ^Fmt_Info, v: any, verb: rune) {
 		write_byte(fi.buf, '[');
 		defer write_byte(fi.buf, ']');
 		slice := cast(^[]byte)v.data;
-		for i in 0..len(slice) {
+		for _, i in slice {
 			if i > 0 {
 				write_string(fi.buf, ", ");
 			}
@@ -856,7 +856,7 @@ fmt_value :: proc(fi: ^Fmt_Info, v: any, verb: rune) {
 		write_byte(fi.buf, '<');
 		defer write_byte(fi.buf, '>');
 
-		for i in 0..info.count {
+		for i in 0..<info.count {
 			if i > 0 {
 				write_string(fi.buf, ", ");
 			}
@@ -1011,7 +1011,7 @@ bprintf :: proc(b: ^[]byte, fmt: string, args: ..any) -> int {
 			i++;
 		}
 		if i > prev_i {
-			write_string(b, fmt[prev_i..i]);
+			write_string(b, fmt[prev_i..<i]);
 		}
 		if i >= end {
 			break;
diff --git a/core/hash.odin b/core/hash.odin
index 5ed4863e0..2f9659f7a 100644
--- a/core/hash.odin
+++ b/core/hash.odin
@@ -175,7 +175,7 @@ murmur64 :: proc(data: []byte) -> u64 {
 		}
 
 		// TODO(bill): Fix this
-		#no_bounds_check data8 := slice_to_bytes(data32[i..])[..3];
+		#no_bounds_check data8 := slice_to_bytes(data32[i..])[..<3];
 		match len {
 		case 3:
 			h2 ~= cast(u32)data8[2] << 16;
diff --git a/core/math.odin b/core/math.odin
index 44e9b50b4..8ad563035 100644
--- a/core/math.odin
+++ b/core/math.odin
@@ -160,8 +160,8 @@ mat4_identity :: proc() -> Mat4 {
 }
 
 mat4_transpose :: proc(m: Mat4) -> Mat4 {
-	for j in 0..4 {
-		for i in 0..4 {
+	for j in 0..<4 {
+		for i in 0..<4 {
 			m[i][j], m[j][i] = m[j][i], m[i][j];
 		}
 	}
@@ -170,8 +170,8 @@ mat4_transpose :: proc(m: Mat4) -> Mat4 {
 
 mul :: proc(a, b: Mat4) -> Mat4 {
 	c: Mat4;
-	for j in 0..4 {
-		for i in 0..4 {
+	for j in 0..<4 {
+		for i in 0..<4 {
 			c[j][i] = a[0][i]*b[j][0] +
 			          a[1][i]*b[j][1] +
 			          a[2][i]*b[j][2] +
diff --git a/core/mem.odin b/core/mem.odin
index f3396b7ac..27146a60d 100644
--- a/core/mem.odin
+++ b/core/mem.odin
@@ -96,7 +96,7 @@ Arena_Temp_Memory :: struct {
 
 init_arena_from_memory :: proc(using a: ^Arena, data: []byte) {
 	backing    = Allocator{};
-	memory     = data[..0];
+	memory     = data[0..<0];
 	temp_count = 0;
 }
 
@@ -169,7 +169,7 @@ begin_arena_temp_memory :: proc(a: ^Arena) -> Arena_Temp_Memory {
 end_arena_temp_memory :: proc(using tmp: Arena_Temp_Memory) {
 	assert(len(arena.memory) >= original_count);
 	assert(arena.temp_count > 0);
-	arena.memory = arena.memory[..original_count];
+	arena.memory = arena.memory[0..<original_count];
 	arena.temp_count--;
 }
 
diff --git a/core/opengl.odin b/core/opengl.odin
index edd754657..3200dc942 100644
--- a/core/opengl.odin
+++ b/core/opengl.odin
@@ -37,7 +37,7 @@ _libgl := win32.LoadLibraryA(_string_data("opengl32.dll\x00"));
 
 GetProcAddress :: proc(name: string) -> proc() #cc_c {
 	if name[len(name)-1] == 0 {
-		name = name[..len(name)-1];
+		name = name[0..<len(name)-1];
 	}
 	// NOTE(bill): null terminated
 	assert((^name[0] + len(name))^ == 0);
diff --git a/core/os_windows.odin b/core/os_windows.odin
index 8d0d7f32e..07d030e16 100644
--- a/core/os_windows.odin
+++ b/core/os_windows.odin
@@ -335,7 +335,7 @@ _alloc_command_line_arguments :: proc() -> []string {
 			}
 		}
 
-		return cast(string)buf[..i];
+		return cast(string)buf[0..<i];
 	}
 
 	arg_count: i32;
diff --git a/core/strconv.odin b/core/strconv.odin
index 983c19403..21a466871 100644
--- a/core/strconv.odin
+++ b/core/strconv.odin
@@ -182,7 +182,7 @@ format_digits :: proc(buf: []byte, shortest: bool, neg: bool, digs: Decimal_Slic
 		// integer, padded with zeros when needed
 		if digs.decimal_point > 0 {
 			m := min(digs.count, digs.decimal_point);
-			append(buf, ..digs.digits[..m]);
+			append(buf, ..digs.digits[0..<m]);
 			for ; m < digs.decimal_point; m++ {
 				append(buf, '0');
 			}
@@ -194,7 +194,7 @@ format_digits :: proc(buf: []byte, shortest: bool, neg: bool, digs: Decimal_Slic
 		// fractional part
 		if prec > 0 {
 			append(buf, '.');
-			for i in 0..prec {
+			for i in 0..<prec {
 				c: byte = '0';
 				if j := digs.decimal_point + i; 0 <= j && j < digs.count {
 					c = digs.digits[j];
@@ -258,7 +258,7 @@ round_shortest :: proc(d: ^Decimal, mant: u64, exp: int, flt: ^Float_Info) {
 
 	inclusive := mant%2 == 0;
 
-	for i in 0..d.count {
+	for i in 0..<d.count {
 		l: byte = '0'; // lower digit
 		if i < lower.count {
 			l = lower.digits[i];
diff --git a/core/utf8.odin b/core/utf8.odin
index b933448b9..db0413885 100644
--- a/core/utf8.odin
+++ b/core/utf8.odin
@@ -160,7 +160,7 @@ decode_last_rune :: proc(s: []byte) -> (rune, int) {
 	}
 
 	start = max(start, 0);
-	r, size = decode_rune(s[start..end]);
+	r, size = decode_rune(s[start..<end]);
 	if start+size != end {
 		return RUNE_ERROR, 1;
 	}
diff --git a/src/check_expr.c b/src/check_expr.c
index 9038d8667..a631bf272 100644
--- a/src/check_expr.c
+++ b/src/check_expr.c
@@ -2819,6 +2819,7 @@ bool check_index_value(Checker *c, AstNode *index_value, i64 max_count, i64 *val
 				return false;
 			}
 
+
 			return true;
 		}
 	}
@@ -5732,6 +5733,11 @@ ExprKind check_expr_base_internal(Checker *c, Operand *o, AstNode *node, Type *t
 			o->mode = Addressing_Value;
 		}
 
+		if (se->low == NULL && se->high != NULL) {
+			error(se->interval0, "1st index is required if a 2nd index is specified");
+			// It is okay to continue as it will assume the 1st index is zero
+		}
+
 		if (se->index3 && (se->high == NULL || se->max == NULL)) {
 			error(se->close, "2nd and 3rd indices are required in a 3-index slice");
 			o->mode = Addressing_Invalid;
@@ -5739,6 +5745,16 @@ ExprKind check_expr_base_internal(Checker *c, Operand *o, AstNode *node, Type *t
 			return kind;
 		}
 
+		if (se->index3 && se->interval0.kind != se->interval1.kind) {
+			error(se->close, "The interval separators for in a 3-index slice must be the same");
+			o->mode = Addressing_Invalid;
+			o->expr = node;
+			return kind;
+		}
+
+
+		TokenKind interval_kind = se->interval0.kind;
+
 		i64 indices[2] = {0};
 		AstNode *nodes[3] = {se->low, se->high, se->max};
 		for (isize i = 0; i < gb_count_of(nodes); i++) {
diff --git a/src/check_stmt.c b/src/check_stmt.c
index ca3bc9ac9..78d646302 100644
--- a/src/check_stmt.c
+++ b/src/check_stmt.c
@@ -771,7 +771,8 @@ void check_stmt_internal(Checker *c, AstNode *node, u32 flags) {
 
 				TokenKind op = Token_Lt;
 				switch (ie->op.kind) {
-				case Token_Ellipsis: op = Token_Lt; break;
+				case Token_Ellipsis:   op = Token_LtEq; break;
+				case Token_HalfClosed: op = Token_Lt; break;
 				default: error(ie->op, "Invalid range operator"); break;
 				}
 				bool ok = compare_exact_values(op, a, b);
diff --git a/src/ir.c b/src/ir.c
index 6fb03d7e0..aaddaf84a 100644
--- a/src/ir.c
+++ b/src/ir.c
@@ -4905,6 +4905,17 @@ irAddr ir_build_addr(irProcedure *proc, AstNode *expr) {
 		if (se->low  != NULL)    low  = ir_build_expr(proc, se->low);
 		if (se->high != NULL)    high = ir_build_expr(proc, se->high);
 		if (se->max  != NULL)    max  = ir_build_expr(proc, se->max);
+
+
+		if (high != NULL && se->interval0.kind == Token_Ellipsis) {
+			high = ir_emit_arith(proc, Token_Add, high, v_one, t_int);
+		}
+
+		if (max != NULL && se->interval1.kind == Token_Ellipsis) {
+			GB_ASSERT(se->interval0.kind == se->interval1.kind);
+			max = ir_emit_arith(proc, Token_Add, max, v_one, t_int);
+		}
+
 		irValue *addr = ir_build_addr(proc, se->expr).addr;
 		irValue *base = ir_emit_load(proc, addr);
 		Type *type = base_type(ir_type(base));
@@ -5553,7 +5564,8 @@ void ir_build_range_interval(irProcedure *proc, AstNodeIntervalExpr *node, Type
 
 	TokenKind op = Token_Lt;
 	switch (node->op.kind) {
-	case Token_Ellipsis: op = Token_Lt; break;
+	case Token_Ellipsis:   op = Token_LtEq; break;
+	case Token_HalfClosed: op = Token_Lt;   break;
 	default: GB_PANIC("Invalid interval operator"); break;
 	}
 	irValue *cond = ir_emit_comp(proc, op, ir_emit_load(proc, value), upper);
diff --git a/src/parser.c b/src/parser.c
index 31d14db78..d9b20fca6 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -105,6 +105,7 @@ typedef enum FieldFlag {
 	FieldFlag_Signature = FieldFlag_ellipsis|FieldFlag_using|FieldFlag_no_alias|FieldFlag_immutable,
 } FieldListTag;
 
+
 AstNodeArray make_ast_node_array(AstFile *f) {
 	AstNodeArray a;
 	// array_init(&a, gb_arena_allocator(&f->arena));
@@ -155,9 +156,11 @@ AST_NODE_KIND(_ExprBegin,  "",  i32) \
 	AST_NODE_KIND(SelectorExpr, "selector expression",    struct { Token token; AstNode *expr, *selector; }) \
 	AST_NODE_KIND(IndexExpr,    "index expression",       struct { AstNode *expr, *index; Token open, close; }) \
 	AST_NODE_KIND(DerefExpr,    "dereference expression", struct { Token op; AstNode *expr; }) \
-	AST_NODE_KIND(SliceExpr, "slice expression", struct { \
+	AST_NODE_KIND(SliceExpr,    "slice expression", struct { \
 		AstNode *expr; \
 		Token open, close; \
+		Token interval0; \
+		Token interval1; \
 		bool index3; \
 		AstNode *low, *high, *max; \
 	}) \
@@ -686,11 +689,13 @@ AstNode *ast_index_expr(AstFile *f, AstNode *expr, AstNode *index, Token open, T
 }
 
 
-AstNode *ast_slice_expr(AstFile *f, AstNode *expr, Token open, Token close, bool index3, AstNode *low, AstNode *high, AstNode *max) {
+AstNode *ast_slice_expr(AstFile *f, AstNode *expr, Token open, Token close, Token interval0, Token interval1, bool index3, AstNode *low, AstNode *high, AstNode *max) {
 	AstNode *result = make_ast_node(f, AstNode_SliceExpr);
 	result->SliceExpr.expr = expr;
 	result->SliceExpr.open = open;
 	result->SliceExpr.close = close;
+	result->SliceExpr.interval0 = interval0;
+	result->SliceExpr.interval1 = interval1;
 	result->SliceExpr.index3 = index3;
 	result->SliceExpr.low = low;
 	result->SliceExpr.high = high;
@@ -1980,15 +1985,19 @@ AstNode *parse_atom_expr(AstFile *f, bool lhs) {
 			f->expr_level++;
 			open = expect_token(f, Token_OpenBracket);
 
-			if (f->curr_token.kind != Token_Ellipsis) {
+			if (f->curr_token.kind != Token_Ellipsis &&
+			    f->curr_token.kind != Token_HalfClosed) {
 				indices[0] = parse_expr(f, false);
 			}
 			bool is_index = true;
 
-			while (f->curr_token.kind == Token_Ellipsis && ellipsis_count < gb_count_of(ellipses)) {
+			while ((f->curr_token.kind == Token_Ellipsis ||
+			        f->curr_token.kind == Token_HalfClosed)
+			        && ellipsis_count < gb_count_of(ellipses)) {
 				ellipses[ellipsis_count++] = f->curr_token;
 				next_token(f);
 				if (f->curr_token.kind != Token_Ellipsis &&
+				    f->curr_token.kind != Token_HalfClosed &&
 				    f->curr_token.kind != Token_CloseBracket &&
 				    f->curr_token.kind != Token_EOF) {
 					indices[ellipsis_count] = parse_expr(f, false);
@@ -2013,7 +2022,7 @@ AstNode *parse_atom_expr(AstFile *f, bool lhs) {
 						indices[2] = ast_bad_expr(f, ellipses[1], close);
 					}
 				}
-				operand = ast_slice_expr(f, operand, open, close, index3, indices[0], indices[1], indices[2]);
+				operand = ast_slice_expr(f, operand, open, close, ellipses[0], ellipses[1], index3, indices[0], indices[1], indices[2]);
 			} else {
 				operand = ast_index_expr(f, operand, indices[0], open, close);
 			}
@@ -2301,6 +2310,7 @@ AstNode *parse_simple_stmt(AstFile *f, bool in_stmt_ok) {
 			allow_token(f, Token_in);
 			AstNode *expr = parse_expr(f, false);
 			switch (f->curr_token.kind) {
+			case Token_HalfClosed:
 			case Token_Ellipsis: {
 				Token op = f->curr_token;
 				next_token(f);
diff --git a/src/tokenizer.c b/src/tokenizer.c
index 469620450..ba491e73c 100644
--- a/src/tokenizer.c
+++ b/src/tokenizer.c
@@ -75,7 +75,7 @@ TOKEN_KIND(Token__ComparisonEnd, "_ComparisonEnd"), \
 	TOKEN_KIND(Token_Period,        "."),   \
 	TOKEN_KIND(Token_Comma,         ","),   \
 	TOKEN_KIND(Token_Ellipsis,      ".."),  \
-	TOKEN_KIND(Token_HalfOpenRange, "..<"), \
+	TOKEN_KIND(Token_HalfClosed,    "..<"), \
 TOKEN_KIND(Token__OperatorEnd, "_OperatorEnd"), \
 \
 TOKEN_KIND(Token__KeywordBegin, "_KeywordBegin"), \
@@ -872,7 +872,7 @@ Token tokenizer_get_token(Tokenizer *t) {
 				token.kind = Token_Ellipsis;
 				if (t->curr_rune == '<') {
 					advance_to_next_rune(t);
-					token.kind = Token_HalfOpenRange;
+					token.kind = Token_HalfClosed;
 				}
 			}
 			break;