GLM: Prepare the lexer to accept nested variables

diff --git a/src/language/stats/glm.c b/src/language/stats/glm.c
index f5feab0e369eaae1541288789b54408bac14b82f..fa418583200781af8fb186b4a160f4dba5602049 100644 (file)
--- a/src/language/stats/glm.c
+++ b/src/language/stats/glm.c
@@ -654,6 +654,20 @@ static bool
 parse_design_interaction (struct lexer *lexer, struct glm_spec *glm)
 {
   const struct variable *v = NULL;
+  switch  (lex_next_token (lexer, 1))
+    {
+    case T_ENDCMD:
+    case T_SLASH:
+    case T_COMMA:
+    case T_ID:
+    case T_BY:
+    case T_ASTERISK:
+      break;
+    default:
+      return false;
+      break;
+    }
+
   if (! lex_match_variable (lexer, glm, &v))
     return false;
 
@@ -670,20 +684,36 @@ parse_design_interaction (struct lexer *lexer, struct glm_spec *glm)
   return true;
 }
 
-/* A design term is a varible OR an interaction */
 static bool
-parse_design_term (struct lexer *lexer, struct glm_spec *glm)
+parse_nested_variable (struct lexer *lexer, struct glm_spec *glm)
 {
   const struct variable *v = NULL;
-  if (parse_design_interaction (lexer, glm))
-    return true;
+  if ( ! lex_match_variable (lexer, glm, &v))
+    return false;
 
-  /* FIXME: This should accept nexted variables */
-  if ( lex_match_variable (lexer, glm, &v))
+  if (lex_match (lexer, T_LPAREN))
     {
-      return true;
+      if ( ! parse_nested_variable (lexer, glm))
+       return false;
+
+      if ( ! lex_force_match (lexer, T_RPAREN))
+       return false;
     }
 
+  lex_error (lexer, "Nested variables are not yet implemented"); return false;  
+  return true;
+}
+
+/* A design term is an interaction OR a nested variable */
+static bool
+parse_design_term (struct lexer *lexer, struct glm_spec *glm)
+{
+  if (parse_design_interaction (lexer, glm))
+    return true;
+
+  if ( parse_nested_variable (lexer, glm))
+    return true;
+
   return false;
 }
 
@@ -696,7 +726,6 @@ parse_design_term (struct lexer *lexer, struct glm_spec *glm)
 static bool
 parse_design_spec (struct lexer *lexer, struct glm_spec *glm)
 {
-  /* Kludge: Return success if end of design spec */
   if  (lex_token (lexer) == T_ENDCMD || lex_token (lexer) == T_SLASH)
     return true;