gen: Add support for the ltree extension (#385)

Author: kyleconroy

internal/dinosql/gen.go

@@ -738,6 +738,17 @@ func (r Result) goInnerType(col core.Column, settings config.CombinedSettings) s
 	case "macaddr", "macaddr8":
 		return "net.HardwareAddr"
 
+	case "ltree", "lquery", "ltxtquery":
+		// This module implements a data type ltree for representing labels
+		// of data stored in a hierarchical tree-like structure. Extensive
+		// facilities for searching through label trees are provided.
+		//
+		// https://www.postgresql.org/docs/current/ltree.html
+		if notNull {
+			return "string"
+		}
+		return "sql.NullString"
+
 	case "void":
 		// A void value always returns NULL. Since there is no built-in NULL
 		// value into the SQL package, we'll use sql.NullBool

internal/endtoend/testdata/ext_ltree/go/db.go

@@ -0,0 +1,9 @@
+CREATE EXTENSION IF NOT EXISTS ltree;
+
+CREATE TABLE foo (
+    qualified_name ltree,
+    name_query lquery,
+    fts_name_query ltxtquery
+);
+
+SELECT * FROM foo;

internal/endtoend/testdata/ext_ltree/go/models.go

@@ -0,0 +1,9 @@
+{
+  "version": "1",
+  "packages": [{
+    "path": "go",
+	"name": "querytest",
+	"schema": "query.sql",
+	"queries": "query.sql"
+  }]
+}