internal/function: make use of typed arity functions

Signed-off-by: Miguel Molina <[email protected]>

Author: erizocosmico

cmd/gitquery/query_base.go

@@ -39,7 +39,8 @@ func (c *cmdQueryBase) buildDatabase() error {
 	}
 
 	c.engine.AddDatabase(gitquery.NewDatabase(c.name, &pool))
-	return function.Register(c.engine.Catalog)
+	function.Register(c.engine.Catalog)
+	return nil
 }
 
 func (c *cmdQueryBase) executeQuery(sql string) (sql.Schema, sql.RowIter, error) {

internal/function/is_remote.go

@@ -14,7 +14,7 @@ type IsRemote struct {
 }
 
 // NewIsRemote creates a new IsRemote function.
-func NewIsRemote(e sql.Expression) *IsRemote {
+func NewIsRemote(e sql.Expression) sql.Expression {
 	return &IsRemote{expression.UnaryExpression{Child: e}}
 }
 

internal/function/is_tag.go

@@ -14,7 +14,7 @@ type IsTag struct {
 }
 
 // NewIsTag creates a new IsTag function.
-func NewIsTag(e sql.Expression) *IsTag {
+func NewIsTag(e sql.Expression) sql.Expression {
 	return &IsTag{expression.UnaryExpression{Child: e}}
 }
 

internal/function/registry.go

@@ -2,18 +2,14 @@ package function
 
 import "gopkg.in/src-d/go-mysql-server.v0/sql"
 
-var functions = map[string]interface{}{
-	"is_tag":    NewIsTag,
-	"is_remote": NewIsRemote,
+var functions = map[string]sql.Function{
+	"is_tag":    sql.Function1(NewIsTag),
+	"is_remote": sql.Function1(NewIsRemote),
 }
 
 // Register all the gitquery functions in the SQL catalog.
-func Register(c *sql.Catalog) error {
+func Register(c *sql.Catalog) {
 	for k, v := range functions {
-		if err := c.RegisterFunction(k, v); err != nil {
-			return err
-		}
+		c.RegisterFunction(k, v)
 	}
-
-	return nil
 }

internal/function/registry_test.go

@@ -10,7 +10,7 @@ import (
 func TestRegister(t *testing.T) {
 	require := require.New(t)
 	catalog := sql.NewCatalog()
-	require.NoError(Register(catalog))
+	Register(catalog)
 
 	for fn := range functions {
 		_, err := catalog.Function(fn)