diff --git a/pkg/compiler/analysis.go b/pkg/compiler/analysis.go
index c2382cfd9..b79d1de85 100644
--- a/pkg/compiler/analysis.go
+++ b/pkg/compiler/analysis.go
@@ -205,50 +205,6 @@ func isBuiltin(expr ast.Expr) bool {
 	return false
 }
 
-func (c *codegen) isCompoundArrayType(t ast.Expr) bool {
-	switch s := t.(type) {
-	case *ast.ArrayType:
-		return true
-	case *ast.Ident:
-		arr, ok := c.typeInfo.Types[s].Type.Underlying().(*types.Slice)
-		return ok && !isByte(arr.Elem())
-	}
-	return false
-}
-
-func isByte(t types.Type) bool {
-	e, ok := t.(*types.Basic)
-	return ok && e.Kind() == types.Byte
-}
-
-func (c *codegen) isStructType(t ast.Expr) (int, bool) {
-	switch s := t.(type) {
-	case *ast.StructType:
-		return s.Fields.NumFields(), true
-	case *ast.Ident:
-		st, ok := c.typeInfo.Types[s].Type.Underlying().(*types.Struct)
-		if ok {
-			return st.NumFields(), true
-		}
-	}
-	return 0, false
-}
-
-func isByteArray(lit *ast.CompositeLit, tInfo *types.Info) bool {
-	if len(lit.Elts) == 0 {
-		if typ, ok := lit.Type.(*ast.ArrayType); ok {
-			if name, ok := typ.Elt.(*ast.Ident); ok {
-				return name.Name == "byte" || name.Name == "uint8"
-			}
-		}
-
-		return false
-	}
-
-	typ := tInfo.Types[lit.Elts[0]].Type.Underlying()
-	return isByte(typ)
-}
-
 func isSyscall(fun *funcScope) bool {
 	if fun.selector == nil {
 		return false
@@ -256,11 +212,3 @@ func isSyscall(fun *funcScope) bool {
 	_, ok := syscalls[fun.selector.Name][fun.name]
 	return ok
 }
-
-func isByteArrayType(t types.Type) bool {
-	return t.String() == "[]byte"
-}
-
-func isStringType(t types.Type) bool {
-	return t.String() == "string"
-}
diff --git a/pkg/compiler/codegen.go b/pkg/compiler/codegen.go
index ca1766d97..54ca11b4d 100644
--- a/pkg/compiler/codegen.go
+++ b/pkg/compiler/codegen.go
@@ -125,16 +125,13 @@ func (c *codegen) emitLoadConst(t types.TypeAndValue) {
 	if c.prog.Err != nil {
 		return
 	}
-	switch typ := t.Type.Underlying().(type) {
-	case *types.Basic:
-		c.convertBasicType(t, typ)
-	default:
+
+	typ, ok := t.Type.Underlying().(*types.Basic)
+	if !ok {
 		c.prog.Err = fmt.Errorf("compiler doesn't know how to convert this constant: %v", t)
 		return
 	}
-}
 
-func (c *codegen) convertBasicType(t types.TypeAndValue, typ *types.Basic) {
 	switch typ.Kind() {
 	case types.Int, types.UntypedInt, types.Uint,
 		types.Int16, types.Uint16,
@@ -376,18 +373,21 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 						ast.Walk(c, val)
 						c.emitStoreVar(t.Names[i].Name)
 					}
-				} else if c.isCompoundArrayType(t.Type) {
-					emit.Opcode(c.prog.BinWriter, opcode.PUSH0)
-					emit.Opcode(c.prog.BinWriter, opcode.NEWARRAY)
-					c.emitStoreVar(t.Names[0].Name)
-				} else if n, ok := c.isStructType(t.Type); ok {
-					emit.Int(c.prog.BinWriter, int64(n))
-					emit.Opcode(c.prog.BinWriter, opcode.NEWSTRUCT)
-					c.emitStoreVar(t.Names[0].Name)
 				} else {
-					for _, id := range t.Names {
-						c.emitDefault(t.Type)
-						c.emitStoreVar(id.Name)
+					typ := c.typeOf(t.Type)
+					if isCompoundSlice(typ) {
+						emit.Opcode(c.prog.BinWriter, opcode.PUSH0)
+						emit.Opcode(c.prog.BinWriter, opcode.NEWARRAY)
+						c.emitStoreVar(t.Names[0].Name)
+					} else if s, ok := typ.Underlying().(*types.Struct); ok {
+						emit.Int(c.prog.BinWriter, int64(s.NumFields()))
+						emit.Opcode(c.prog.BinWriter, opcode.NEWSTRUCT)
+						c.emitStoreVar(t.Names[0].Name)
+					} else {
+						for _, id := range t.Names {
+							c.emitDefault(t.Type)
+							c.emitStoreVar(id.Name)
+						}
 					}
 				}
 			}
@@ -430,8 +430,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 				switch expr := t.X.(type) {
 				case *ast.Ident:
 					ast.Walk(c, n.Rhs[i])
-					typ := c.typeInfo.ObjectOf(expr).Type().Underlying()
-					if strct, ok := typ.(*types.Struct); ok {
+					if strct, ok := c.typeOf(expr).Underlying().(*types.Struct); ok {
 						c.emitLoadVar(expr.Name)              // load the struct
 						i := indexOfStruct(strct, t.Sel.Name) // get the index of the field
 						c.emitStoreStructField(i)             // store the field
@@ -607,7 +606,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 		return nil
 
 	case *ast.BasicLit:
-		c.emitLoadConst(c.typeInfo.Types[n])
+		c.emitLoadConst(c.typeAndValueOf(n))
 		return nil
 
 	case *ast.Ident:
@@ -618,7 +617,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 				return nil
 			}
 			c.emitLoadConst(value)
-		} else if tv := c.typeInfo.Types[n]; tv.Value != nil {
+		} else if tv := c.typeAndValueOf(n); tv.Value != nil {
 			c.emitLoadConst(tv)
 		} else {
 			c.emitLoadVar(n.Name)
@@ -626,19 +625,19 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 		return nil
 
 	case *ast.CompositeLit:
-		var typ types.Type
-
-		switch t := n.Type.(type) {
-		case *ast.Ident:
-			typ = c.typeInfo.ObjectOf(t).Type().Underlying()
-		case *ast.SelectorExpr:
-			typ = c.typeInfo.ObjectOf(t.Sel).Type().Underlying()
-		case *ast.MapType:
-			typ = c.typeInfo.TypeOf(t)
+		typ := c.typeOf(n.Type).Underlying()
+		switch n.Type.(type) {
+		case *ast.Ident, *ast.SelectorExpr, *ast.MapType:
+			switch typ.(type) {
+			case *types.Struct:
+				c.convertStruct(n)
+			case *types.Map:
+				c.convertMap(n)
+			}
 		default:
 			ln := len(n.Elts)
 			// ByteArrays needs a different approach than normal arrays.
-			if isByteArray(n, c.typeInfo) {
+			if isByteSlice(typ) {
 				c.convertByteArray(n)
 				return nil
 			}
@@ -647,14 +646,6 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 			}
 			emit.Int(c.prog.BinWriter, int64(ln))
 			emit.Opcode(c.prog.BinWriter, opcode.PACK)
-			return nil
-		}
-
-		switch typ.(type) {
-		case *types.Struct:
-			c.convertStruct(n)
-		case *types.Map:
-			c.convertMap(n)
 		}
 
 		return nil
@@ -693,7 +684,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 			// example:
 			// const x = 10
 			// x + 2 will results into 12
-			tinfo := c.typeInfo.Types[n]
+			tinfo := c.typeAndValueOf(n)
 			if tinfo.Value != nil {
 				c.emitLoadConst(tinfo)
 				return nil
@@ -705,7 +696,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 			switch {
 			case n.Op == token.ADD:
 				// VM has separate opcodes for number and string concatenation
-				if isStringType(tinfo.Type) {
+				if isString(tinfo.Type) {
 					emit.Opcode(c.prog.BinWriter, opcode.CAT)
 				} else {
 					emit.Opcode(c.prog.BinWriter, opcode.ADD)
@@ -716,7 +707,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 				emit.Opcode(c.prog.BinWriter, op)
 			case n.Op == token.NEQ:
 				// VM has separate opcodes for number and string equality
-				if isStringType(c.typeInfo.Types[n.X].Type) {
+				if isString(c.typeOf(n.X)) {
 					emit.Opcode(c.prog.BinWriter, opcode.NOTEQUAL)
 				} else {
 					emit.Opcode(c.prog.BinWriter, opcode.NUMNOTEQUAL)
@@ -800,8 +791,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 	case *ast.SelectorExpr:
 		switch t := n.X.(type) {
 		case *ast.Ident:
-			typ := c.typeInfo.ObjectOf(t).Type().Underlying()
-			if strct, ok := typ.(*types.Struct); ok {
+			if strct, ok := c.typeOf(t).Underlying().(*types.Struct); ok {
 				c.emitLoadVar(t.Name) // load the struct
 				i := indexOfStruct(strct, n.Sel.Name)
 				c.emitLoadField(i) // load the field
@@ -852,14 +842,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 
 		switch n.Index.(type) {
 		case *ast.BasicLit:
-			t := c.typeInfo.Types[n.Index]
-			switch typ := t.Type.Underlying().(type) {
-			case *types.Basic:
-				c.convertBasicType(t, typ)
-			default:
-				c.prog.Err = fmt.Errorf("compiler can't use following type as an index: %T", typ)
-				return nil
-			}
+			c.emitLoadConst(c.typeAndValueOf(n.Index))
 		default:
 			ast.Walk(c, n.Index)
 		}
@@ -1067,7 +1050,7 @@ func (c *codegen) getLabelOffset(typ labelOffsetType, name string) uint16 {
 }
 
 func (c *codegen) getEqualityOpcode(expr ast.Expr) opcode.Opcode {
-	t, ok := c.typeInfo.Types[expr].Type.Underlying().(*types.Basic)
+	t, ok := c.typeOf(expr).Underlying().(*types.Basic)
 	if ok && t.Info()&types.IsNumeric != 0 {
 		return opcode.NUMEQUAL
 	}
@@ -1080,18 +1063,18 @@ func (c *codegen) getEqualityOpcode(expr ast.Expr) opcode.Opcode {
 func (c *codegen) getByteArray(expr ast.Expr) []byte {
 	switch t := expr.(type) {
 	case *ast.CompositeLit:
-		if !isByteArray(t, c.typeInfo) {
+		if !isByteSlice(c.typeOf(t.Type)) {
 			return nil
 		}
 		buf := make([]byte, len(t.Elts))
 		for i := 0; i < len(t.Elts); i++ {
-			t := c.typeInfo.Types[t.Elts[i]]
+			t := c.typeAndValueOf(t.Elts[i])
 			val, _ := constant.Int64Val(t.Value)
 			buf[i] = byte(val)
 		}
 		return buf
 	case *ast.CallExpr:
-		if tv := c.typeInfo.Types[t.Args[0]]; tv.Value != nil {
+		if tv := c.typeAndValueOf(t.Args[0]); tv.Value != nil {
 			val := constant.StringVal(tv.Value)
 			return []byte(val)
 		}
@@ -1136,7 +1119,7 @@ func (c *codegen) convertBuiltin(expr *ast.CallExpr) {
 	case "append":
 		arg := expr.Args[0]
 		typ := c.typeInfo.Types[arg].Type
-		if isByteArrayType(typ) {
+		if isByteSlice(typ) {
 			emit.Opcode(c.prog.BinWriter, opcode.CAT)
 		} else {
 			emit.Opcode(c.prog.BinWriter, opcode.OVER)
@@ -1148,7 +1131,7 @@ func (c *codegen) convertBuiltin(expr *ast.CallExpr) {
 		if isExprNil(arg) {
 			emit.Opcode(c.prog.BinWriter, opcode.DROP)
 			emit.Opcode(c.prog.BinWriter, opcode.THROW)
-		} else if isStringType(c.typeInfo.Types[arg].Type) {
+		} else if isString(c.typeInfo.Types[arg].Type) {
 			ast.Walk(c, arg)
 			emit.Syscall(c.prog.BinWriter, "Neo.Runtime.Log")
 			emit.Opcode(c.prog.BinWriter, opcode.THROW)
@@ -1216,7 +1199,7 @@ func transformArgs(fun ast.Expr, args []ast.Expr) []ast.Expr {
 func (c *codegen) convertByteArray(lit *ast.CompositeLit) {
 	buf := make([]byte, len(lit.Elts))
 	for i := 0; i < len(lit.Elts); i++ {
-		t := c.typeInfo.Types[lit.Elts[i]]
+		t := c.typeAndValueOf(lit.Elts[i])
 		val, _ := constant.Int64Val(t.Value)
 		buf[i] = byte(val)
 	}
@@ -1237,7 +1220,7 @@ func (c *codegen) convertMap(lit *ast.CompositeLit) {
 func (c *codegen) convertStruct(lit *ast.CompositeLit) {
 	// Create a new structScope to initialize and store
 	// the positions of its variables.
-	strct, ok := c.typeInfo.TypeOf(lit).Underlying().(*types.Struct)
+	strct, ok := c.typeOf(lit).Underlying().(*types.Struct)
 	if !ok {
 		c.prog.Err = fmt.Errorf("the given literal is not of type struct: %v", lit)
 		return
diff --git a/pkg/compiler/debug.go b/pkg/compiler/debug.go
index 29af3f425..9f174b5cc 100644
--- a/pkg/compiler/debug.go
+++ b/pkg/compiler/debug.go
@@ -191,7 +191,11 @@ func (c *codegen) scReturnTypeFromScope(scope *funcScope) string {
 }
 
 func (c *codegen) scTypeFromExpr(typ ast.Expr) string {
-	switch t := c.typeInfo.Types[typ].Type.(type) {
+	t := c.typeOf(typ)
+	if c.typeOf(typ) == nil {
+		return "Any"
+	}
+	switch t := t.Underlying().(type) {
 	case *types.Basic:
 		info := t.Info()
 		switch {
@@ -209,7 +213,7 @@ func (c *codegen) scTypeFromExpr(typ ast.Expr) string {
 	case *types.Struct:
 		return "Struct"
 	case *types.Slice:
-		if isByteArrayType(t) {
+		if isByte(t.Elem()) {
 			return "ByteArray"
 		}
 		return "Array"
diff --git a/pkg/compiler/types.go b/pkg/compiler/types.go
new file mode 100644
index 000000000..2011220fc
--- /dev/null
+++ b/pkg/compiler/types.go
@@ -0,0 +1,44 @@
+package compiler
+
+import (
+	"go/ast"
+	"go/types"
+)
+
+func (c *codegen) typeAndValueOf(e ast.Expr) types.TypeAndValue {
+	return c.typeInfo.Types[e]
+}
+
+func (c *codegen) typeOf(e ast.Expr) types.Type {
+	return c.typeAndValueOf(e).Type
+}
+
+func isBasicTypeOfKind(typ types.Type, ks ...types.BasicKind) bool {
+	if t, ok := typ.Underlying().(*types.Basic); ok {
+		k := t.Kind()
+		for i := range ks {
+			if k == ks[i] {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+func isByte(typ types.Type) bool {
+	return isBasicTypeOfKind(typ, types.Uint8, types.Int8)
+}
+
+func isString(typ types.Type) bool {
+	return isBasicTypeOfKind(typ, types.String)
+}
+
+func isCompoundSlice(typ types.Type) bool {
+	t, ok := typ.Underlying().(*types.Slice)
+	return ok && !isByte(t.Elem())
+}
+
+func isByteSlice(typ types.Type) bool {
+	t, ok := typ.Underlying().(*types.Slice)
+	return ok && isByte(t.Elem())
+}