Fmlib_parse.Error_reporterConvenience module to generate readable error messages.
An error reporter is a parser which reparses the input stream, extracts the failed code snippet and prints the error nicely formatted.
For semantic errors, the module needs support from the user to convert a semantic error into a pretty print document.
The error reporter generates a pretty print document (details about pretty print documents see Fmlib_pretty.Print) of the form
code snippet containing the error with markers at the error
description of the errorThe description of the error is in case of a syntax error a description of what might have been expected at the error position and in case of a semantic error whatever the user provides as an error description.
The generated error report has one of the following forms:
Syntax error:
25 | xxxx
26 |
27 | line with error
^
I have encountered something unexpected. I was expecting one of
- xxx
- yyy
- zzz
...Semantic error on one line:
25 | xxxx
26 |
27 | line with error
^^^^^
User supplied description of the semantic errorSemantic error spanning several lines
25 | xxxx
26 |
v----------
27 | xxx yyy error start
28 | err err err err err
29 | err err err
30 | err error end zzz
-----------------^
User supplied description of the semantic errormodule type FAILED_PARSER = sig ... endNeeded functions from a failed parser i.e. a parser which has failed either with a syntax error or a semantic error.
module Make (Parser : FAILED_PARSER) : sig ... endGenerate the error reporter from a failed parser.