v.parser: add a generated .all(.flag1|.flag2) method to [flag] enums

Unlike `.has(.flag1|.flag2)`, which is true, for any of `.flag1` or `.flag2`,
the new method `.all()` tests whether *all flags* are set at the same time.

doc/docs.md

@@ -5344,14 +5344,23 @@ enum BitField {
 	other
 }
 
-fn example_enum_as_bitfield_use() {
+fn main() {
 	assert 1 == int(BitField.read)
 	assert 2 == int(BitField.write)
 	mut bf := BitField.read
+	assert bf.has(.read | .other) // test if *at least one* of the flags is set
+	assert !bf.all(.read | .other) // test if *all* of the flags is set
 	bf.set(.write | .other)
 	assert bf.has(.read | .write | .other)
+	assert bf.all(.read | .write | .other)
+	bf.toggle(.other)
+	assert bf == BitField.read | .write
+	assert bf.all(.read | .write)
+	assert !bf.has(.other)
 }
+```
 
+```v
 // Calling this function will result in a deprecation warning
 [deprecated]
 fn old_function() {
@@ -5372,7 +5381,9 @@ fn legacy_function() {}
 [deprecated: 'use new_function2() instead']
 [deprecated_after: '2021-05-27']
 fn legacy_function2() {}
+```
 
+```v nofmt
 // This function's calls will be inlined.
 [inline]
 fn inlined_function() {

vlib/v/parser/parser.v

@@ -3146,6 +3146,7 @@ fn (mut p Parser) enum_decl() ast.EnumDecl {
 //
 [inline] $pubfn (    e &$enum_name) is_empty() bool           { return  int(*e) == 0 }
 [inline] $pubfn (    e &$enum_name) has(flag $enum_name) bool { return  (int(*e) &  (int(flag))) != 0 }
+[inline] $pubfn (    e &$enum_name) all(flag $enum_name) bool { return  (int(*e) &  (int(flag))) == int(flag) }
 [inline] $pubfn (mut e  $enum_name) set(flag $enum_name)      { unsafe{ *e = ${enum_name}(int(*e) |  (int(flag))) } }
 [inline] $pubfn (mut e  $enum_name) clear(flag $enum_name)    { unsafe{ *e = ${enum_name}(int(*e) & ~(int(flag))) } }
 [inline] $pubfn (mut e  $enum_name) toggle(flag $enum_name)   { unsafe{ *e = ${enum_name}(int(*e) ^  (int(flag))) } }

vlib/v/tests/enum_bitfield_test.v

@@ -26,6 +26,9 @@ fn test_enum_bitfield() {
 	assert a.perm.has(.execute)
 	assert !a.perm.has(.write)
 	assert !a.perm.has(.other)
+}
+
+fn test_enum_bitfield_operators() {
 	mut b := BfPermission.read | BfPermission.execute
 	assert int(b) == 1 + 0 + 4 + 0
 	assert b.has(.read)
@@ -42,11 +45,35 @@ fn test_enum_bitfield() {
 	assert int(b) == 0 + 2 + 0 + 8
 	assert !b.has(.read)
 	assert !b.has(.execute)
+}
 
+fn test_enum_bitfield_has_vs_all_methods_with_combined_flags() {
 	mut c := BfPermission.read
 	c.set(.write | .execute)
 	assert c.has(.read | .write | .execute)
 	assert !c.has(.other)
-	c.toggle(.write | .other)
-	assert '$c' == 'BfPermission{.read | .execute | .other}'
+	assert c.has(.read | .write | .execute | .other)
+	// .all() tests if *ALL* of the given flags are set, i.e. not just any one of them.
+	// .has() tests if *ANY* of the given flags is set, even though some of the others may not be.
+	assert c.all(.read | .write | .execute)
+	assert !c.all(.read | .write | .execute | .other)
+}
+
+fn test_enum_bitfield_has_vs_all_methods_with_combined_flags_2() {
+	mut c := BfPermission.read | .execute | .other
+	//
+	assert c.has(.read | .execute | .other | .write)
+	assert c.has(.read | .write)
+	assert !c.all(.read | .execute | .other | .write)
+	assert !c.all(.read | .write)
+	//
+	assert c.all(.read | .execute | .other)
+	assert c.all(.read | .execute)
+	assert c.all(.execute | .other)
+	assert c.all(.read | .other)
+	//
+	assert c.has(.read | .execute | .other)
+	assert c.has(.read | .execute)
+	assert c.has(.execute | .other)
+	assert c.has(.read | .other)
 }