recognize variables when parsing (bug #38576) * lex.h, lex.ll (lexical_feedback::mark_as_variable, lexical_feedback::maybe_mark_previous_token_as_variable, lexical_feedback::mark_as_variables, octave_lexer::is_variable): New fucntions. ("="): Call maybe_mark_previous_toke_as_variable. (handle_identifier): Don't tag variables as possible commands. (param_list): Mark names in list as variables. (octave_base_parser::validate_matrix_for_assignment): Likewise. * pt-arg-list.h, pt-arg-list.cc (tree_argument_list::variable_names): New function. * pt-misc.h, pt-misc.cc (tree_parameter_list::variable_names): New function. * token.h, token.cc (token::symbol_name, token::is_symbol): New functions. * test/bug-38576.tst: New file. * test/Makefile.am (FCN_FILES): Add bug-38576.tst to the list.

--- a/libinterp/parse-tree/lex.h
+++ b/libinterp/parse-tree/lex.h
@@ -307,6 +307,11 @@
 
   bool previous_token_may_be_command (void) const;
 
+  void maybe_mark_previous_token_as_variable (void);
+
+  void mark_as_variable (const std::string& nm);
+  void mark_as_variables (const std::list<std::string>& lst);
+
   // true means that we have encountered eof on the input stream.
   bool end_of_input;
 
@@ -518,6 +523,8 @@
 
   bool inside_any_object_index (void);
 
+  bool is_variable (const std::string& name);
+
   int is_keyword_token (const std::string& s);
 
   bool whitespace_is_significant (void);