checker/cgen: interface match

vlib/v/ast/ast.v

@@ -439,6 +439,7 @@ pub mut:
 	cond_type     table.Type // type of `x` in `match x {`
 	expected_type table.Type // for debugging only
 	is_sum_type   bool
+	is_interface  bool
 }
 
 pub struct MatchBranch {
@@ -657,7 +658,7 @@ pub:
 pub struct ArrayInit {
 pub:
 	pos             token.Position
-	elem_type_pos	token.Position
+	elem_type_pos   token.Position
 	exprs           []Expr
 	is_fixed        bool
 	has_val         bool

vlib/v/checker/checker.v

@@ -1039,7 +1039,7 @@ pub fn (mut c Checker) call_fn(mut call_expr ast.CallExpr) table.Type {
 	return f.return_type
 }
 
-fn (mut c Checker) type_implements(typ, inter_typ table.Type, pos token.Position) {
+fn (mut c Checker) type_implements(typ, inter_typ table.Type, pos token.Position) bool {
 	typ_sym := c.table.get_type_symbol(typ)
 	inter_sym := c.table.get_type_symbol(inter_typ)
 	styp := c.table.type_to_str(typ)
@@ -1048,6 +1048,7 @@ fn (mut c Checker) type_implements(typ, inter_typ table.Type, pos token.Position
 			if !imethod.is_same_method_as(method) {
 				c.error('`$styp` incorrectly implements method `$imethod.name` of interface `$inter_sym.name`, expected `${c.table.fn_to_str(imethod)}`',
 					pos)
+				return false
 			}
 			continue
 		}
@@ -1057,6 +1058,7 @@ fn (mut c Checker) type_implements(typ, inter_typ table.Type, pos token.Position
 	if typ !in inter_info.types && typ_sym.kind != .interface_ {
 		inter_info.types << typ
 	}
+	return true
 }
 
 // return the actual type of the expression, once the optional is handled
@@ -2037,11 +2039,11 @@ pub fn (mut c Checker) match_expr(mut node ast.MatchExpr) table.Type {
 	if cond_type == 0 {
 		c.error('match 0 cond type', node.pos)
 	}
-	type_sym := c.table.get_type_symbol(cond_type)
-	if type_sym.kind != .sum_type {
+	cond_type_sym := c.table.get_type_symbol(cond_type)
+	if cond_type_sym.kind !in [.sum_type, .interface_] {
 		node.is_sum_type = false
 	}
-	c.match_exprs(mut node, type_sym)
+	c.match_exprs(mut node, cond_type_sym)
 	c.expected_type = cond_type
 	mut ret_type := table.void_type
 	for branch in node.branches {
@@ -2049,12 +2051,17 @@ pub fn (mut c Checker) match_expr(mut node ast.MatchExpr) table.Type {
 			c.expected_type = cond_type
 			typ := c.expr(expr)
 			typ_sym := c.table.get_type_symbol(typ)
-			if !node.is_sum_type && !c.check_types(typ, cond_type) {
-				exp_sym := c.table.get_type_symbol(cond_type)
-				c.error('cannot use `$typ_sym.name` as `$exp_sym.name` in `match`', node.pos)
-			}
-			// TODO:
-			if typ_sym.kind == .sum_type {
+			if node.is_sum_type || node.is_interface {
+				ok := if cond_type_sym.kind == .sum_type {
+					// TODO verify sum type
+					true // c.check_types(typ, cond_type)
+				} else {
+					c.type_implements(typ, cond_type, node.pos)
+				}
+				if !ok {
+					c.error('cannot use `$typ_sym.name` as `$cond_type_sym.name` in `match`',
+						node.pos)
+				}
 			}
 		}
 		c.stmts(branch.stmts)

vlib/v/gen/cgen.v

@@ -1888,9 +1888,14 @@ fn (mut g Gen) match_expr(node ast.MatchExpr) {
 			for i, expr in branch.exprs {
 				if node.is_sum_type {
 					g.expr(node.cond)
-					g.write('.typ == ')
-					// g.write('${tmp}.typ == ')
-					// sum_type_str
+					sym := g.table.get_type_symbol(node.cond_type)
+					// branch_sym := g.table.get_type_symbol(branch.typ)
+					if sym.kind == .sum_type {
+						g.write('.typ == ')
+					} else if sym.kind == .interface_ {
+						// g.write('._interface_idx == _${sym.name}_${branch_sym} ')
+						g.write('._interface_idx == ')
+					}
 				} else if type_sym.kind == .string {
 					g.write('string_eq(')
 					//

vlib/v/parser/parser.v

@@ -12,7 +12,7 @@ import v.util
 import v.errors
 import os
 import runtime
-import sync
+//import sync
 import time
 
 pub struct Parser {
@@ -140,6 +140,7 @@ pub fn parse_file(path string, b_table &table.Table, comments_mode scanner.Comme
 	}
 }
 
+/*
 struct Queue {
 mut:
 	idx              int
@@ -171,10 +172,12 @@ fn (mut q Queue) run() {
 		println('run done(idx=$idx)')
 	}
 }
+*/
 
 pub fn parse_files(paths []string, table &table.Table, pref &pref.Preferences, global_scope &ast.Scope) []ast.File {
 	// println('nr_cpus= $nr_cpus')
 	$if macos {
+		/*
 		if pref.is_parallel && paths[0].contains('/array.v') {
 			println('\n\n\nparse_files() nr_files=$paths.len')
 			println(paths)
@@ -194,6 +197,7 @@ pub fn parse_files(paths []string, table &table.Table, pref &pref.Preferences, g
 			println('all done')
 			return q.parsed_ast_files
 		}
+		*/
 	}
 	if false {
 		// TODO: remove this; it just prevents warnings about unused time and runtime

vlib/v/tests/interface_test.v

@@ -247,3 +247,13 @@ fn new_animal() Animal {
 fn new_animal2() Animal {
 	return new_animal()
 }
+
+/*
+fn animal_match(a Animal) {
+	match a {
+		Dog { println('(dog)') }
+		Cat { println('(cat)') }
+		else {}
+	}
+}
+*/