Implemented reading from struct fields

tests/errors/UnknownStructField.q

@@ -0,0 +1,6 @@
+struct A {}
+
+main() {
+	a := new(A)
+	a.x = 1
+}

tests/errors_test.go

@@ -48,6 +48,7 @@ var errs = []struct {
 	{"UnknownIdentifier2.q", &errors.UnknownIdentifier{Name: "x"}},
 	{"UnknownIdentifier3.q", &errors.UnknownIdentifier{Name: "x"}},
 	{"UnknownPackage.q", &errors.UnknownPackage{Name: "sys"}},
+	{"UnknownStructField.q", &errors.UnknownStructField{StructName: "A", FieldName: "x"}},
 	{"UnusedImport.q", &errors.UnusedImport{Package: "sys"}},
 	{"UnusedVariable.q", &errors.UnusedVariable{Name: "x"}},
 	{"VariableAlreadyExists.q", &errors.VariableAlreadyExists{Name: "x"}},

tests/examples_test.go

@@ -24,6 +24,7 @@ var examples = []struct {
 	{"itoa", "", "9223372036854775807", 0},
 	{"collatz", "", "6 3 10 5 16 8 4 2 1", 0},
 	{"fizzbuzz", "", "1 2 Fizz 4 Buzz Fizz 7 8 Fizz Buzz 11 Fizz 13 14 FizzBuzz", 0},
+	{"point", "", "x 1\ny 2\n", 0},
 	{"prime", "", "2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97", 0},
 }
 

tests/programs/struct.q

@@ -0,0 +1,34 @@
+struct Point {
+	x Int
+	y Int
+}
+
+main() {
+	p := new(Point)
+	assert p.x == 0
+	assert p.y == 0
+	assert p.x == p.y
+
+	p.x = 1
+	p.y = 2
+	assert p.x == 1
+	assert p.y == 2
+	assert p.x != p.y
+
+	p.x = p.y
+	assert p.x == 2
+	assert p.y == 2
+	assert p.x == p.y
+
+	p.x = p.y + 1
+	assert p.x == 3
+	assert p.y == 2
+	assert p.x != p.y
+
+	p.y = p.x
+	assert p.x == 3
+	assert p.y == 3
+	assert p.x == p.y
+
+	delete(p)
+}

tests/programs_test.go

@@ -60,6 +60,7 @@ var programs = []struct {
 	{"loop", "", "", 0},
 	{"loop-lifetime", "", "", 0},
 	{"out-of-memory", "", "", 0},
+	{"struct", "", "", 0},
 }
 
 func TestPrograms(t *testing.T) {