cgen: fix array.insert and arr.prepend

vlib/builtin/array_test.v

@@ -113,54 +113,40 @@ fn test_push() {
 	assert a.str() == '[1, 3]'
 }
 
-// TODO array.insert is broken
-// Cannot pass literal or primitive type as it cannot be cast to voidptr.
-// In the current state only that would work:
-// i := 3
-// a.insert(0, &i)
-// ----------------------------
-/*
 fn test_insert() {
 	mut a := [1, 2]
 	a.insert(0, 3)
-	println(a)
+	assert a[0] == 3
+	assert a[2] == 2
+	assert a.len == 3
+	a.insert(1, 4)
+	assert a[1] == 4
+	assert a[2] == 1
+	assert a.len == 4
+	a.insert(4, 5)
+	assert a[4] == 5
+	assert a[3] == 2
+	assert a.len == 5
+	mut b := []f64{}
+	assert b.len == 0
+	b.insert(0, f64(1.1))
+	assert b.len == 1
+	assert b[0] == f64(1.1)
 }
-*/
-// fn test_insert() {
-// mut a := [1, 2]
-// a.insert(0, 3)
-// assert a[0] == 3
-// assert a[2] == 2
-// assert a.len == 3
-// a.insert(1, 4)
-// assert a[1] == 4
-// assert a[2] == 1
-// assert a.len == 4
-// a.insert(4, 5)
-// assert a[4] == 5
-// assert a[3] == 2
-// assert a.len == 5
-// mut b := []f64{}
-// assert b.len == 0
-// b.insert(0, f64(1.1))
-// assert b.len == 1
-// assert b[0] == f64(1.1)
-// }
-// TODO array.prepend is broken
-// It depends on array.insert
-// -----------------------------
-// fn test_prepend() {
-// mut a := []int{}
-// assert a.len == 0
-// a.prepend(1)
-// assert a.len == 1
-// assert a[0] == 1
-// mut b := []f64{}
-// assert b.len == 0
-// b.prepend(f64(1.1))
-// assert b.len == 1
-// assert b[0] == f64(1.1)
-// }
+
+fn test_prepend() {
+	mut a := []int{}
+	assert a.len == 0
+	a.prepend(1)
+	assert a.len == 1
+	assert a[0] == 1
+	mut b := []f64{}
+	assert b.len == 0
+	b.prepend(f64(1.1))
+	assert b.len == 1
+	assert b[0] == f64(1.1)
+}
+
 fn test_strings() {
 	a := ['a', 'b', 'c']
 	assert a.str() == "['a', 'b', 'c']"

vlib/v/gen/cgen.v

@@ -3069,7 +3069,7 @@ fn (mut g Gen) gen_expr_to_string(expr ast.Expr, etype table.Type) ?bool {
 }
 
 // `nums.map(it % 2 == 0)`
-fn (mut g Gen) gen_map(node ast.CallExpr) {
+fn (mut g Gen) gen_array_map(node ast.CallExpr) {
 	tmp := g.new_tmp_var()
 	s := g.go_before_stmt(0)
 	// println('filter s="$s"')
@@ -3127,7 +3127,7 @@ fn (mut g Gen) gen_map(node ast.CallExpr) {
 }
 
 // `nums.filter(it % 2 == 0)`
-fn (mut g Gen) gen_filter(node ast.CallExpr) {
+fn (mut g Gen) gen_array_filter(node ast.CallExpr) {
 	tmp := g.new_tmp_var()
 	s := g.go_before_stmt(0)
 	// println('filter s="$s"')
@@ -3177,6 +3177,38 @@ fn (mut g Gen) gen_filter(node ast.CallExpr) {
 	g.write(tmp)
 }
 
+// `nums.insert(0, 2)`
+fn (mut g Gen) gen_array_insert(node ast.CallExpr) {
+	sym := g.table.get_type_symbol(node.left_type)
+	if sym.kind != .array {
+		verror('insert() requires an array')
+	}
+	info := sym.info as table.Array
+	elem_type_str := g.typ(info.elem_type)
+	g.write('array_insert(&')
+	g.expr(node.left)
+	g.write(', ')
+	g.expr(node.args[0].expr)
+	g.write(', &($elem_type_str[]){')
+	g.expr(node.args[1].expr)
+	g.write('});')
+}
+
+// `nums.prepend(2)`
+fn (mut g Gen) gen_array_prepend(node ast.CallExpr) {
+	sym := g.table.get_type_symbol(node.left_type)
+	if sym.kind != .array {
+		verror('prepend() requires an array')
+	}
+	info := sym.info as table.Array
+	elem_type_str := g.typ(info.elem_type)
+	g.write('array_prepend(&')
+	g.expr(node.left)
+	g.write(', &($elem_type_str[]){')
+	g.expr(node.args[0].expr)
+	g.write('});')
+}
+
 [inline]
 fn (g &Gen) nth_stmt_pos(n int) int {
 	return g.stmt_path_pos[g.stmt_path_pos.len - (1 + n)]

vlib/v/gen/fn.v

@@ -359,14 +359,27 @@ fn (mut g Gen) method_call(node ast.CallExpr) {
 		g.write(')')
 		return
 	}
-	if typ_sym.kind == .array && node.name == 'map' {
-		g.gen_map(node)
-		return
-	}
-	// rec_sym := g.table.get_type_symbol(node.receiver_type)
-	if typ_sym.kind == .array && node.name == 'filter' {
-		g.gen_filter(node)
-		return
+	left_sym := g.table.get_type_symbol(node.left_type)
+	if left_sym.kind == .array {
+		match node.name {
+			'filter' {
+				g.gen_array_filter(node)
+				return
+			}
+			'insert' {
+				g.gen_array_insert(node)
+				return
+			}
+			'map' {
+				g.gen_array_map(node)
+				return
+			}
+			'prepend' {
+				g.gen_array_prepend(node)
+				return
+			}
+			else {}
+		}
 	}
 	if node.name == 'str' {
 		mut styp := g.typ(node.receiver_type)
@@ -376,7 +389,7 @@ fn (mut g Gen) method_call(node ast.CallExpr) {
 		g.gen_str_for_type_with_styp(node.receiver_type, styp)
 	}
 	// TODO performance, detect `array` method differently
-	if typ_sym.kind == .array && node.name in ['repeat', 'sort_with_compare', 'free', 'push_many',
+	if left_sym.kind == .array && node.name in ['repeat', 'sort_with_compare', 'free', 'push_many',
 		'trim',
 		'first',
 		'last',