xgo/runtime/vm_inc_dec_test.go

22 lines
734 B
Go

package runtime_test
import (
"testing"
)
func TestIncDec(t *testing.T) {
expect(t, `out = 0; out++`, 1)
expect(t, `out = 0; out--`, -1)
expect(t, `a := 0; a++; out = a`, 1)
expect(t, `a := 0; a++; a--; out = a`, 0)
// this seems strange but it works because 'a += b' is
// translated into 'a = a + b' and string type takes other types for + operator.
expect(t, `a := "foo"; a++; out = a`, "foo1")
expectError(t, `a := "foo"; a--`, "invalid operation")
expectError(t, `a++`, "unresolved reference") // not declared
expectError(t, `a--`, "unresolved reference") // not declared
//expectError(t, `a := 0; b := a++`) // inc-dec is statement not expression <- parser error
expectError(t, `4++`, "unresolved reference")
}