Minor improvements to astbuilder

hack/generator/pkg/astbuilder/builder.go

@@ -18,11 +18,8 @@ import (
 // 		return <otherReturns...>, err
 //	}
 func CheckErrorAndReturn(otherReturns ...dst.Expr) dst.Stmt {
-	returnValues := append([]dst.Expr{}, cloneExprSlice(otherReturns)...)
-	returnValues = append(returnValues, dst.NewIdent("err"))
-
 	retStmt := &dst.ReturnStmt{
-		Results: returnValues,
+		Results: Expressions(otherReturns, dst.NewIdent("err")),
 	}
 
 	return CheckErrorAndSingleStatement(retStmt)
@@ -230,7 +227,7 @@ func ReturnIfExpr(cond dst.Expr, returns ...dst.Expr) *dst.IfStmt {
 		Body: &dst.BlockStmt{
 			List: []dst.Stmt{
 				&dst.ReturnStmt{
-					Results: cloneExprSlice(returns),
+					Results: Expressions(returns),
 				},
 			},
 		},
@@ -294,7 +291,7 @@ func Returns(returns ...dst.Expr) dst.Stmt {
 				Before: dst.NewLine,
 			},
 		},
-		Results: cloneExprSlice(returns),
+		Results: Expressions(returns),
 	}
 }
 
@@ -376,7 +373,7 @@ func Nil() *dst.Ident {
 // StatementBlock generates a block containing the supplied statements
 func StatementBlock(statements ...dst.Stmt) *dst.BlockStmt {
 	return &dst.BlockStmt{
-		List: cloneStmtSlice(statements),
+		List: Statements(statements),
 	}
 }
 
@@ -393,41 +390,54 @@ func EnsureStatementBlock(statement dst.Stmt) *dst.BlockStmt {
 // Statements creates a sequence of statements from the provided values, each of which may be a
 // single dst.Stmt or a slice of multiple []dst.Stmts
 func Statements(statements ...interface{}) []dst.Stmt {
-	var result []dst.Stmt
+	var stmts []dst.Stmt
 	for _, s := range statements {
 		switch s := s.(type) {
 		case nil:
 			// Skip nils
 			continue
 		case dst.Stmt:
 			// Add a single statement
-			result = append(result, s)
+			stmts = append(stmts, s)
 		case []dst.Stmt:
 			// Add many statements
-			result = append(result, s...)
+			stmts = append(stmts, s...)
 		default:
 			panic(fmt.Sprintf("expected dst.Stmt or []dst.Stmt, but found %T", s))
 		}
 	}
 
-	return result
-}
-
-// cloneExprSlice is a utility method to clone a slice of expressions
-func cloneExprSlice(exprs []dst.Expr) []dst.Expr {
-	var result []dst.Expr
-	for _, exp := range exprs {
-		result = append(result, dst.Clone(exp).(dst.Expr))
+	var result []dst.Stmt
+	for _, st := range stmts {
+		result = append(result, dst.Clone(st).(dst.Stmt))
 	}
 
 	return result
 }
 
-// cloneStmtSlice is a utility method to clone a slice of statements
-func cloneStmtSlice(stmts []dst.Stmt) []dst.Stmt {
-	var result []dst.Stmt
-	for _, st := range stmts {
-		result = append(result, dst.Clone(st).(dst.Stmt))
+// Expression creates a sequence of expressions from the provided values, each of which may be a
+// single dst.Expr or a slice of multiple []dst.Expr
+func Expressions(statements ...interface{}) []dst.Expr {
+	var exprs []dst.Expr
+	for _, e := range statements {
+		switch s := e.(type) {
+		case nil:
+			// Skip nils
+			continue
+		case dst.Expr:
+			// Add a single expression
+			exprs = append(exprs, s)
+		case []dst.Expr:
+			// Add many expressions
+			exprs = append(exprs, s...)
+		default:
+			panic(fmt.Sprintf("expected dst.Expr or []dst.Expr, but found %T", s))
+		}
+	}
+
+	var result []dst.Expr
+	for _, ex := range exprs {
+		result = append(result, dst.Clone(ex).(dst.Expr))
 	}
 
 	return result

hack/generator/pkg/astbuilder/calls.go

@@ -16,7 +16,7 @@ import (
 func CallFunc(funcName string, arguments ...dst.Expr) *dst.CallExpr {
 	return &dst.CallExpr{
 		Fun:  dst.NewIdent(funcName),
-		Args: cloneExprSlice(arguments),
+		Args: Expressions(arguments),
 	}
 }
 
@@ -31,7 +31,7 @@ func CallQualifiedFunc(qualifier string, funcName string, arguments ...dst.Expr)
 			X:   dst.NewIdent(qualifier),
 			Sel: dst.NewIdent(funcName),
 		},
-		Args: cloneExprSlice(arguments),
+		Args: Expressions(arguments),
 	}
 }
 
@@ -45,7 +45,7 @@ func CallExpr(expr dst.Expr, funcName string, arguments ...dst.Expr) dst.Expr {
 			X:   expr,
 			Sel: dst.NewIdent(funcName),
 		},
-		Args: cloneExprSlice(arguments),
+		Args: Expressions(arguments),
 	}
 }