diff --git a/HISTORY.asc b/HISTORY.asc
index 887bce7..1c3e53b 100644
--- a/HISTORY.asc
+++ b/HISTORY.asc
@@ -1,3 +1,14 @@
-0.2.1
------
+STABLE
+------
 === Fix bug where extension could not be dropped
+The extension now requires extension_drop and trunklet 0.3.3 or later, neither of which 0.2.0 required. Updating from trunklet-format 0.2.0 (PostgreSQL 12 or later) requires trunklet >= 0.3.3:
+
+* If you are on trunklet 0.2.1 or later, run `ALTER EXTENSION trunklet UPDATE;` first, then `CREATE EXTENSION extension_drop CASCADE;` and `ALTER EXTENSION "trunklet-format" UPDATE;`.
+* trunklet 0.2.0 has no update path to later versions: drop and recreate it (this also drops trunklet-format and any trunklet data), then install trunklet-format at the stable version.
+
+=== Add optional parameters
+A parameter written as `%name%Os` or `%name%OL` may be absent from the parameters, in which case it is treated as NULL. Identifiers (`I`) cannot be optional.
+
+=== Other changes
+* `extract_parameters()` returns NULL instead of an error when none of the requested parameters are present.
+* Template parse errors report the position in the template.
diff --git a/META.in.json b/META.in.json
index f62b8a1..67e359c 100644
--- a/META.in.json
+++ b/META.in.json
@@ -16,7 +16,7 @@
     "name": "trunklet-format",
 
     "X_comment": "REQUIRED. Version of the distribution. http://pgxn.org/spec/#version",
-    "version": "0.2.0",
+    "version": "stable",
 
     "X_comment": "REQUIRED. Short description of distribution.",
     "abstract": "A format()-based template language for trunklet",
@@ -41,7 +41,7 @@
             "file": "sql/trunklet-format.sql",
 
             "X_comment": "REQUIRED. Version the extension is at.",
-            "version": "0.2.0",
+            "version": "stable",
 
             "X_comment": "Optional: \"abstract\": Description of the extension.",
             "abstract": "A format()-based template language for trunklet",
@@ -75,20 +75,20 @@
     "X_comment": "Requires JSONB, which was released in 9.4",
     "X_comment": "trunklet currently requires 9.5",
     "X_comment": "extension_drop: 0.1.1 fixes bug with dependencies",
-    "X_comment": "Requires support for droping a language in trunklet; released in 0.3.0",
+    "X_comment": "trunklet 0.3.3: the drop command uses template_language__remove(ignore_missing_functions), added in 0.3.3",
     "prereqs": {
 
         "build": {
             "requires": {
                 "PostgreSQL": "9.5.0",
                 "extension_drop": ">= 0.1.1",
-                "trunklet": ">= 0.3.0"
+                "trunklet": ">= 0.3.3"
             }
         },
         "runtime": {
             "requires": {
                 "plpgsql": 0,
-                "trunklet": ">= 0.2.0"
+                "trunklet": ">= 0.3.3"
             }
         },
         "test": {
diff --git a/META.json b/META.json
index 94b02ca..4475eb6 100644
--- a/META.json
+++ b/META.json
@@ -16,7 +16,7 @@
     "name": "trunklet-format",
 
     "X_comment": "REQUIRED. Version of the distribution. http://pgxn.org/spec/#version",
-    "version": "0.2.0",
+    "version": "stable",
 
     "X_comment": "REQUIRED. Short description of distribution.",
     "abstract": "A format()-based template language for trunklet",
@@ -41,7 +41,7 @@
             "file": "sql/trunklet-format.sql",
 
             "X_comment": "REQUIRED. Version the extension is at.",
-            "version": "0.2.0",
+            "version": "stable",
 
             "X_comment": "Optional: \"abstract\": Description of the extension.",
             "abstract": "A format()-based template language for trunklet",
@@ -75,20 +75,20 @@
     "X_comment": "Requires JSONB, which was released in 9.4",
     "X_comment": "trunklet currently requires 9.5",
     "X_comment": "extension_drop: 0.1.1 fixes bug with dependencies",
-    "X_comment": "Requires support for droping a language in trunklet; released in 0.3.0",
+    "X_comment": "trunklet 0.3.3: the drop command uses template_language__remove(ignore_missing_functions), added in 0.3.3",
     "prereqs": {
 
         "build": {
             "requires": {
                 "PostgreSQL": "9.5.0",
                 "extension_drop": ">= 0.1.1",
-                "trunklet": ">= 0.3.0"
+                "trunklet": ">= 0.3.3"
             }
         },
         "runtime": {
             "requires": {
                 "plpgsql": 0,
-                "trunklet": ">= 0.2.0"
+                "trunklet": ">= 0.3.3"
             }
         },
         "test": {
diff --git a/README.md b/README.md
index af242ac..9db7b39 100644
--- a/README.md
+++ b/README.md
@@ -53,6 +53,18 @@ super user and running:
 
     CREATE EXTENSION "trunklet-format";
 
+Updating an existing trunklet-format 0.2.0 install (PostgreSQL 12 or later)
+requires trunklet >= 0.3.3 and extension_drop, neither of which 0.2.0 required.
+If you are on trunklet 0.2.1 or later, run:
+
+    ALTER EXTENSION trunklet UPDATE;
+    CREATE EXTENSION extension_drop CASCADE;
+    ALTER EXTENSION "trunklet-format" UPDATE;
+
+trunklet 0.2.0 has no update path to later versions: drop and recreate it (this
+also drops trunklet-format and any trunklet data), then install trunklet-format
+at the stable version.
+
 If you want to install trunklet-format and all of its supporting objects into a specific
 schema, use the `PGOPTIONS` environment variable to specify the schema, like
 so:
diff --git a/sql/trunklet-format--0.2.0--stable.sql b/sql/trunklet-format--0.2.0--stable.sql
new file mode 100644
index 0000000..2f24aa9
--- /dev/null
+++ b/sql/trunklet-format--0.2.0--stable.sql
@@ -0,0 +1,321 @@
+-- The drop command below needs trunklet 0.3.3 (ignore_missing_functions); a non-numeric version such as stable passes
+DO $$
+DECLARE
+  v_version CONSTANT text := (SELECT extversion FROM pg_catalog.pg_extension WHERE extname = 'trunklet');
+BEGIN
+  IF v_version ~ '^[0-9]+(\.[0-9]+)*$' AND string_to_array(v_version, '.')::int[] < '{0,3,3}' THEN
+    RAISE EXCEPTION 'trunklet >= 0.3.3 required; found %', v_version
+      USING ERRCODE = 'object_not_in_prerequisite_state'
+        , HINT = 'On trunklet 0.2.1 or later, run ALTER EXTENSION trunklet UPDATE first. trunklet 0.2.0 has no update path; see the trunklet-format README.'
+    ;
+  END IF;
+END
+$$;
+
+/*
+ * 0.2.0 could not be dropped. Register the same drop command the install
+ * script does; this is why extension_drop is now a required extension.
+ */
+SELECT extension_drop__add(
+  'trunklet-format'
+  -- WARNING! Our language name is format, not trunklet-format!
+  , $sql$SELECT trunklet.template_language__remove('format', ignore_missing_functions := true)$sql$
+);
+
+/*
+ * trunklet has no public API to replace a language, and removing then
+ * re-adding it fails on stored templates (or, with cascade, deletes them), so
+ * update trunklet's private tables and functions the way
+ * template_language__add() does.
+ */
+SELECT _trunklet.language__get_id('format'); -- Throws if the language is missing
+
+UPDATE _trunklet.language
+  SET process_function_body = $process_body$
+DECLARE
+  c_param CONSTANT jsonb := parameters::jsonb;
+  v_return text;
+BEGIN
+  -- DUPLICATED IN BOTH FUNCTIONS
+  IF jsonb_typeof(c_param) <> 'object' THEN
+    RAISE EXCEPTION 'parameters must be a JSON object, not %', jsonb_typeof(c_param)
+      USING DETAIL = format('parameters = %L', c_param)
+    ;
+  END IF;
+
+  -- Sanity-check parameters
+  -- DUPLICATED IN BOTH FUNCTIONS
+  DECLARE
+    parameter_name text;
+    value text;
+    v_type text;
+  BEGIN
+    FOR parameter_name, value IN SELECT * FROM jsonb_each( c_param )
+    LOOP
+      IF parameter_name ~ '%' THEN
+        RAISE EXCEPTION
+          USING DETAIL = 'parameter_name ' || parameter_name
+            -- MESSAGE instead of trying to escape %
+            , MESSAGE = 'parameter names may not contain "%"'
+        ;
+      END IF;
+
+      v_type := jsonb_typeof( c_param->parameter_name );
+      IF v_type IN ( 'array', 'object' ) THEN
+        RAISE EXCEPTION '% is not supported as a parameter type', v_type
+          USING DETAIL = format( $$paramater %s = %s$$, parameter_name, value )
+        ;
+      END IF;
+    END LOOP;
+  END;
+
+  /*
+   * Look for things to replace
+   */
+  DECLARE
+    c_parse CONSTANT text[] := string_to_array( template::text, '%' );
+    c_alen CONSTANT int := array_length( c_parse, 1 );
+
+    /*
+     * TODO: Instead of trying to track exact template position, it would be
+     * easier to just track the accumulated length of every c_parse element
+     * we've seen. That can be converted to template position by simply adding
+     * (v_pos-1) * length('%').
+     */
+    v_template_pos int := 1 + length(c_parse[1]); -- Start at 1 and account for c_parse[1]
+
+    v_pos int := 2; -- We handle first element specially
+    v_format_option_position int;
+    v_last_parameter_position int;
+    v_cur text = ''; -- Needs to start at '' for template position tracking
+    v_parameter text;
+    v_optional boolean;
+    v_format_option text;
+    v_value text;
+  BEGIN
+    /*
+     * We have to special-case the first element because we know it must be
+     * plain text with no paramaters, or empty if the template starts with '%%'.
+     */
+    v_return := c_parse[1];
+    WHILE v_pos <= c_alen LOOP
+      v_template_pos := v_template_pos + 1; -- We just consumed a %
+      v_cur := c_parse[v_pos];
+      --RAISE WARNING 'v_template_pos = %, v_pos = %, v_cur = %', v_template_pos, v_pos, v_cur;
+
+      /*
+       * The %% escape gives us an empty v_cur.
+       */
+      IF v_cur = '' THEN
+        /*
+         * If we have the template '1 %% 2 %param%s' then when we hit this
+         * condition we're 'inside' the %% (v_pos = 2, v_cur = ''). The code
+         * below this IF block depends on v_cur being a parameter name. This
+         * means we have to consume the NEXT array element (v_pos = 3) before
+         * continuing, because it could ALSO be empty (ie: '%%%param%s'). It
+         * could NOT be a parameter though.
+         */
+
+        -- Update our position
+        v_template_pos = v_template_pos + length(c_parse[v_pos + 1]) + 1;
+        -- v_cur will immediately be reset
+        
+        -- Append the % and the next array element
+        v_return := v_return || '%' || c_parse[v_pos + 1];
+        v_pos := v_pos + 2;
+        CONTINUE;
+      END IF;
+
+      /*
+       * Since we don't allow % in a parameter name, we know that v_cur IS THE NAME OF A PARAMETER.
+       */
+      v_last_parameter_position := v_template_pos - 1; -- -1 for the '%'
+      v_parameter := v_cur;
+      v_pos := v_pos + 1;
+      IF v_pos > c_alen THEN
+        RAISE EXCEPTION 'Reached end of template while processing parameters'
+          USING HINT = E'Parameters must match the format "%parameter_name%[O]T" where T is s, I or L\n'
+            || 'and O (if present) means the parameter is optional.'
+        ;
+      END IF;
+
+      v_template_pos = v_template_pos + length(v_cur) + 1;
+      v_cur := c_parse[v_pos];
+      --RAISE WARNING 'v_template_pos = %, v_pos = %, v_cur = %', v_template_pos, v_pos, v_cur;
+      /*
+       * At this point v_cur IS THE OPTIONS SPECIFIER
+       */
+
+      -- This is where to insert support for other format option handling
+      -- These ugly shenanigans are to avoid copying a potentially large string multiple times
+      v_optional := substr( v_cur, 1, 1 ) = 'O';
+      v_format_option_position := CASE v_optional WHEN true THEN 2 WHEN false THEN 1 END;
+      v_template_pos = v_template_pos + v_format_option_position - 1; -- -1 because we haven't technically consumed the format specifier yet
+      v_format_option = substr( v_cur, v_format_option_position, 1 );
+      --RAISE WARNING 'FORMAT OPTION %, v_template_pos = %, v_pos = %, v_format_option_position = %, v_cur = %', v_format_option, v_template_pos, v_pos, v_format_option_position, v_cur;
+
+      --RAISE WARNING 'v_pos = %, v_cur = %, v_format_option = %', v_pos, v_cur, v_format_option;
+      IF v_format_option NOT IN ( 's', 'I', 'L' ) THEN
+        RAISE EXCEPTION 'Unexpected character "%" in format specifier "%"'
+            , v_format_option
+            , substr(v_cur, 1, v_format_option_position )
+          USING DETAIL = format( 'parameter "%s" at template position %s', v_parameter, v_last_parameter_position )
+        ;
+      END IF;
+
+      IF v_optional THEN
+        IF v_format_option = 'I' THEN
+          RAISE EXCEPTION 'SQL identifier format option ("I") not allowed with optional parameters'
+            USING ERRCODE = 'null_value_not_allowed'
+              , HINT = 'SQL identifiers can not be NULL or empty, so identifier formats may not be optional.'
+              , DETAIL = format( 'parameter "%s" at template position %s', v_parameter, v_last_parameter_position )
+          ;
+        END IF;
+        -- c_param->v_parameter will ONLY be NULL if v_parameter doesn't exist in the document
+      ELSIF (c_param->v_parameter) IS NULL THEN
+        RAISE EXCEPTION 'parameter "%" not found', v_parameter
+          USING DETAIL = format( 'at template position %s', v_last_parameter_position )
+        ;
+      END IF;
+
+
+      -- Now that we've consumed the format specifier, update v_template_pos and grab our value
+      v_template_pos := v_template_pos + 1;
+      v_value := c_param->>v_parameter;
+
+      /*
+      RAISE WARNING 'v_template_pos = %, v_pos = %, v_parameter = %, v_format_option = %, v_value = %, v_format_option_position = %'
+        , v_template_pos, v_pos, v_parameter, v_format_option, v_value, v_format_option_position
+        USING DETAIL = format(
+          'prior "%s", next: "%s"'
+          , substr(template, v_template_pos-20, 20)
+          , substr(template, v_template_pos, 20)
+        )
+      ;
+      */
+      v_return := v_return
+        -- This is the actual replacement
+        || format(
+          '%' || v_format_option
+          , v_value
+        )
+
+        -- Remainder of document, up to next '%'
+        || substr( v_cur, v_format_option_position + 1 )
+      ;
+      v_template_pos := v_template_pos + length(v_cur) - v_format_option_position;
+      v_pos := v_pos + 1;
+    END LOOP;
+  END;
+
+  RETURN v_return;
+END
+$process_body$
+    , extract_parameters_body = $extract_body$
+DECLARE
+  c_param CONSTANT jsonb := parameters::jsonb;
+  a_as text[];
+  sql text;
+  r record;
+BEGIN
+  -- DUPLICATED IN BOTH FUNCTIONS
+  IF jsonb_typeof(c_param) <> 'object' THEN
+    RAISE EXCEPTION 'parameters must be a JSON object, not %', jsonb_typeof(c_param)
+      USING DETAIL = format('parameters = %L', c_param)
+    ;
+  END IF;
+
+  -- Sanity-check parameters
+  -- DUPLICATED IN BOTH FUNCTIONS
+  DECLARE
+    parameter_name text;
+    value text;
+    v_type text;
+  BEGIN
+    FOR parameter_name, value IN SELECT * FROM jsonb_each( c_param )
+    LOOP
+      IF parameter_name ~ '%' THEN
+        RAISE EXCEPTION
+          USING DETAIL = 'parameter_name ' || parameter_name
+            -- MESSAGE instead of trying to escape %
+            , MESSAGE = 'parameter names may not contain "%"'
+        ;
+      END IF;
+
+      v_type := jsonb_typeof( c_param->parameter_name );
+      IF v_type IN ( 'array', 'object' ) THEN
+        RAISE EXCEPTION '% is not supported as a parameter type', v_type
+          USING DETAIL = format( $$paramater %s = %s$$, parameter_name, value )
+        ;
+      END IF;
+
+      -- THIS IS SPECIFIC TO extract_parametrs
+      IF parameter_name = ANY( extract_list ) THEN
+        a_as := a_as || format(
+          '%I %s'
+          , parameter_name
+          , CASE
+              WHEN v_type IN( 'string', 'null' ) THEN 'text'
+              WHEN v_type = 'number' THEN 'numeric'
+              -- array and object can't happen
+              ELSE v_type
+            END
+        );
+      END IF;
+    END LOOP;
+  END;
+
+  -- Nothing matched
+  IF a_as IS NULL THEN
+    RETURN NULL;
+  END IF;
+
+  sql := 'SELECT * FROM jsonb_to_record($1) AS j(' || array_to_string( a_as, ', ' ) || ')';
+  RAISE DEBUG 'sql = %', sql;
+  EXECUTE sql INTO r USING c_param;
+  RETURN row_to_json(r)::jsonb;
+END
+$extract_body$
+  WHERE language_name = 'format'
+;
+
+SELECT _trunklet._language_function__create(
+    language_id
+    , language_name
+    , 'process'
+    , 'text'
+    , format(
+      $args$
+    template %s
+    , parameters %s
+$args$
+      , template_type
+      , parameter_type
+    )
+    , process_function_options
+    , process_function_body
+  )
+  FROM _trunklet.language
+  WHERE language_name = 'format'
+;
+
+SELECT _trunklet._language_function__create(
+    language_id
+    , language_name
+    , 'extract_parameters'
+    , parameter_type::text
+    , format(
+      $args$
+    parameters %s
+    , extract_list text[]
+$args$
+      , parameter_type
+    )
+    , extract_parameters_options
+    , extract_parameters_body
+  )
+  FROM _trunklet.language
+  WHERE language_name = 'format'
+;
+
+-- vi: expandtab ts=2 sw=2
diff --git a/sql/trunklet-format--0.2.0.sql b/sql/trunklet-format--0.2.0.sql
new file mode 100644
index 0000000..c3bb967
--- /dev/null
+++ b/sql/trunklet-format--0.2.0.sql
@@ -0,0 +1,177 @@
+SELECT trunklet.template_language__add(
+  language_name := 'format'
+  , parameter_type := 'jsonb'
+  , template_type := 'text'
+  , process_function_options := 'LANGUAGE plpgsql'
+  , process_function_body := $process_body$
+DECLARE
+  c_param CONSTANT jsonb := parameters::jsonb;
+  v_return text;
+BEGIN
+  -- DUPLICATED IN BOTH FUNCTIONS
+  IF jsonb_typeof(c_param) <> 'object' THEN
+    RAISE EXCEPTION 'parameters must be a JSON object, not %', jsonb_typeof(c_param)
+      USING DETAIL = 'parameters = ' || c_param
+    ;
+  END IF;
+
+  -- Sanity-check parameters
+  -- DUPLICATED IN BOTH FUNCTIONS
+  DECLARE
+    parameter_name text;
+    value text;
+    v_type text;
+  BEGIN
+    FOR parameter_name, value IN SELECT * FROM jsonb_each( c_param )
+    LOOP
+      IF parameter_name ~ '%' THEN
+        RAISE EXCEPTION
+          USING DETAIL = 'parameter_name ' || parameter_name
+            -- MESSAGE instead of trying to escape %
+            , MESSAGE = 'parameter names may not contain "%"'
+        ;
+      END IF;
+
+      v_type := jsonb_typeof( c_param->parameter_name );
+      IF v_type IN ( 'array', 'object' ) THEN
+        RAISE EXCEPTION '% is not supported as a parameter type', v_type
+          USING DETAIL = format( $$paramater %s = %s$$, parameter_name, value )
+        ;
+      END IF;
+    END LOOP;
+  END;
+
+  /*
+   * Look for things to replace
+   */
+  DECLARE
+    c_parse CONSTANT text[] := string_to_array( template::text, '%' );
+    c_alen CONSTANT int := array_length( c_parse, 1 );
+    v_pos int := 2; -- We handle first element specially
+    v_cur text;
+    v_first text;
+    v_value text;
+  BEGIN
+    /*
+     * We have to special-case the first element because we know it must be
+     * plain text with no paramaters, or empty if the template starts with '%%'.
+     */
+    v_return := c_parse[1];
+    WHILE v_pos <= c_alen LOOP
+      v_cur := c_parse[v_pos];
+      --RAISE WARNING 'v_pos = %, v_cur = %', v_pos, v_cur;
+
+      /*
+       * The %% escape gives us an empty v_cur.
+       */
+      IF v_cur = '' THEN
+        -- The next parse element won't be a 
+        /*
+         * If we have the template '1 %% 2 %param%s' then when we hid this
+         * condition we're 'inside' the %% (v_pos = 2, v_cur = ''). The code
+         * below this IF block depends on v_cur being a parameter name. This
+         * means we have to consume v_pos = 3 before continuing.
+         */
+        v_return := v_return || '%' || c_parse[v_pos + 1];
+        v_pos := v_pos + 2;
+        CONTINUE;
+      END IF;
+
+      /*
+       * Since we don't allow % in a parameter name, we know that v_cur is the name of a parameter.
+       */
+      IF (c_param->v_cur) IS NULL THEN
+        RAISE EXCEPTION 'parameter "%" not found', v_cur
+          USING DETAIL = 'parse position ' || v_pos
+        ;
+      END IF;
+      v_value := CASE WHEN jsonb_typeof(c_param->v_cur) = 'null' THEN NULL ELSE c_param->>v_cur END;
+      v_pos := v_pos + 1;
+      IF v_pos > c_alen THEN
+        RAISE EXCEPTION 'Reached end of template while processing parameters'
+          USING HINT = 'Parameters must match the format "%parameter_name%T" where T is s, I or L.'
+        ;
+      END IF;
+      v_cur := c_parse[v_pos];
+
+      -- This is where to insert support for other format option handling
+      v_first := substr( v_cur, 1, 1 );
+      --RAISE WARNING 'v_pos = %, v_cur = %, v_first = %', v_pos, v_cur, v_first;
+      IF v_first NOT IN ( 's', 'I', 'L' ) THEN
+        RAISE EXCEPTION 'Unexpected character "%" trailing parameter "%"', v_first, c_parse[v_pos - 1]
+          USING DETAIL = format( 'parse position %s, parameter name %s', v_pos, c_parse[v_pos - 1] )
+        ;
+      END IF;
+
+      v_return := v_return || format( '%' || v_first, v_value ) || substr( v_cur, 2 );
+      v_pos := v_pos + 1;
+    END LOOP;
+  END;
+
+  RETURN v_return;
+END
+$process_body$
+  , extract_parameters_options := 'LANGUAGE plpgsql'
+  , extract_parameters_body := $extract_body$
+DECLARE
+  c_param CONSTANT jsonb := parameters::jsonb;
+  a_as text[];
+  sql text;
+  r record;
+BEGIN
+  -- DUPLICATED IN BOTH FUNCTIONS
+  IF jsonb_typeof(c_param) <> 'object' THEN
+    RAISE EXCEPTION 'parameters must be a JSON object, not %', jsonb_typeof(c_param)
+      USING DETAIL = 'parameters = ' || c_param
+    ;
+  END IF;
+
+  -- Sanity-check parameters
+  -- DUPLICATED IN BOTH FUNCTIONS
+  DECLARE
+    parameter_name text;
+    value text;
+    v_type text;
+  BEGIN
+    FOR parameter_name, value IN SELECT * FROM jsonb_each( c_param )
+    LOOP
+      IF parameter_name ~ '%' THEN
+        RAISE EXCEPTION
+          USING DETAIL = 'parameter_name ' || parameter_name
+            -- MESSAGE instead of trying to escape %
+            , MESSAGE = 'parameter names may not contain "%"'
+        ;
+      END IF;
+
+      v_type := jsonb_typeof( c_param->parameter_name );
+      IF v_type IN ( 'array', 'object' ) THEN
+        RAISE EXCEPTION '% is not supported as a parameter type', v_type
+          USING DETAIL = format( $$paramater %s = %s$$, parameter_name, value )
+        ;
+      END IF;
+
+      -- THIS IS SPECIFIC TO extract_parametrs
+      IF parameter_name = ANY( extract_list ) THEN
+        a_as := a_as || format(
+          '%I %s'
+          , parameter_name
+          , CASE
+              WHEN v_type IN( 'string', 'null' ) THEN 'text'
+              WHEN v_type = 'number' THEN 'numeric'
+              -- array and object can't happen
+              ELSE v_type
+            END
+        );
+      END IF;
+    END LOOP;
+  END;
+
+  sql := 'SELECT * FROM jsonb_to_record($1) AS j(' || array_to_string( a_as, ', ' ) || ')';
+  RAISE DEBUG 'sql = %', sql;
+  EXECUTE sql INTO r USING c_param;
+  RETURN row_to_json(r)::jsonb;
+END
+$extract_body$
+);
+
+-- vi: expandtab ts=2 sw=2
diff --git a/trunklet-format.control b/trunklet-format.control
index fe292bf..4faee9a 100644
--- a/trunklet-format.control
+++ b/trunklet-format.control
@@ -1,5 +1,5 @@
 # trunklet-format extension
 comment = 'A format()-based template language for trunklet'
-default_version = '0.2.0'
+default_version = 'stable'
 relocatable = true
 requires = 'trunklet, extension_drop'