Identifier completion for incomplete program text based on Yacc error recovery

This page provides an implementation of identifier completion for a small subset of Standard ML as an Emacs-mode based on the approach presented in the following paper:

How to use

Download mode.tar.gz, unzip and untar it, and then follow the instructions in README file.
A bug was fixed on Jan 6, 2015.
Another bug was fixed on Feb 16, 2015.

Screen shot

An example of using yyerrok;

As for the discussion in Section 4.5 in the paper above, add the special statement yyerrok; in the action description in the case of LET dec IN exp error in the file "sml.y" as follows.
| LET dec IN exp error
  $$ = make_atexp4 ($2, $4);
This enables the completion on the example in Section 4.5.