allow slicing of fixed size arrays

vlib/builtin/array_test.v

@@ -246,6 +246,7 @@ fn test_slice() {
 	assert a.len == 4
 }
 
+
 fn test_push_many() {
 	mut a := [1, 2, 3]
 	b := [4, 5, 6]
@@ -283,6 +284,8 @@ struct Foooj {
 
 fn test_fixed() {
 	mut nums := [4]int
+	x := nums[1..3]
+	assert x.len == 2
 	assert nums[0] == 0
 	assert nums[1] == 0
 	assert nums[2] == 0

vlib/v/checker/checker.v

@@ -1014,22 +1014,32 @@ pub fn (c mut Checker) index_expr(node mut ast.IndexExpr) table.Type {
 		else {}
 	}
 	node.container_type = typ
+	typ_sym := c.table.get_type_symbol(typ)
 	if !is_range {
-		typ_sym := c.table.get_type_symbol(typ)
 		index_type := c.expr(node.index)
 		index_type_sym := c.table.get_type_symbol(index_type)
 		// println('index expr left=$typ_sym.name $node.pos.line_nr')
-		if typ_sym.kind == .array && (!(table.type_idx(index_type) in table.number_type_idxs) && index_type_sym.kind != .enum_) {
+		// if typ_sym.kind == .array && (!(table.type_idx(index_type) in table.number_type_idxs) && index_type_sym.kind != .enum_) {
+		if typ_sym.kind in [.array, .array_fixed] && !(table.is_number(index_type) && index_type_sym.kind != .enum_) {
 			c.error('non-integer index `$index_type_sym.name` (array type `$typ_sym.name`)', node.pos)
 		}
 		else if typ_sym.kind == .map && table.type_idx(index_type) != table.string_type_idx {
-			c.error('non-string map index (type `$typ_sym.name`)', node.pos)
+			c.error('non-string map index (map type `$typ_sym.name`)', node.pos)
 		}
 		value_type := c.table.value_type(typ)
 		if value_type != table.void_type {
 			return value_type
 		}
 	}
+	else if is_range {
+		// array[1..2] => array
+		// fixed_array[1..2] => array
+		if typ_sym.kind == .array_fixed {
+			elem_type := c.table.value_type(typ)
+			idx := c.table.find_or_register_array(elem_type, 1)
+			return table.new_type(idx)
+		}
+	}
 	return typ
 }
 

vlib/v/gen/cgen.v

@@ -776,7 +776,7 @@ fn (g mut Gen) gen_fn_decl(it ast.FnDecl) {
 		g.definitions.writeln(');')
 	}
 	if is_main {
-		g.writeln('_vinit();')
+		g.writeln('\t_vinit();')
 		if g.is_importing_os() {
 			if g.autofree {
 				g.writeln('free(_const_os__args.data); // empty, inited in _vinit()')
@@ -792,12 +792,12 @@ fn (g mut Gen) gen_fn_decl(it ast.FnDecl) {
 	// /////////
 	if is_main {
 		if g.autofree {
-			g.writeln('_vcleanup();')
+			g.writeln('\t_vcleanup();')
 		}
 		if g.is_test {
 			verror('test files cannot have function `main`')
 		}
-		g.writeln('return 0;')
+		g.writeln('\treturn 0;')
 	}
 	if g.defer_stmts.len > 0 {
 		g.write_defer_stmts()
@@ -1567,11 +1567,27 @@ fn (g mut Gen) index_expr(node ast.IndexExpr) {
 			is_range = true
 			if sym.kind == .string {
 				g.write('string_substr(')
+				g.expr(node.left)
 			}
 			else if sym.kind == .array {
 				g.write('array_slice(')
+				g.expr(node.left)
+			}
+			else if sym.kind == .array_fixed {
+				// Convert a fixed array to V array when doing `fixed_arr[start..end]`
+				g.write('array_slice(new_array_from_c_array(sizeof(')
+				g.expr(node.left)
+				g.write('), sizeof(')
+				g.expr(node.left)
+				g.write('), sizeof(')
+				g.expr(node.left)
+				g.write('[0]), ')
+				g.expr(node.left)
+				g.write(')')
+			}
+			else {
+				g.expr(node.left)
 			}
-			g.expr(node.left)
 			g.write(', ')
 			if it.has_low {
 				g.expr(it.low)
@@ -2603,7 +2619,7 @@ pub fn (g mut Gen) write_tests_main() {
 		g.writeln('\tBenchedTests_end_testing(&bt);')
 	}
 	g.writeln('')
-	g.writeln('_vcleanup();')
+	g.writeln('\t_vcleanup();')
 	g.writeln('\treturn g_test_fails > 0;')
 	g.writeln('}')
 }

vlib/v/gen/cheaders.v

@@ -191,6 +191,7 @@ void reload_so();
 void _vinit();
 void _vcleanup();
 #define sigaction_size sizeof(sigaction);
+#define _ARR_LEN(a) ( (sizeof(a)) / (sizeof((a)[0])) );
 
 // ============== wyhash ==============
 //	Author: Wang Yi

vlib/v/table/atypes.v

@@ -149,6 +149,10 @@ pub fn is_number(typ Type) bool {
 */
 
 
+pub fn is_number(typ Type) bool {
+	return type_idx(typ) in number_type_idxs
+}
+
 pub const (
 // primitive types
 	void_type_idx = 1