Source entered interactively can now be displayed in traceback output. Also,
the REPL object is now available in its namespace, so that, for instance,
display options--like `spy`--can be turned on and off interactively.
Closeshylang/hy#1397.
Compiler and command-line error messages now reflect their Python counterparts.
E.g. where Python emits a `SyntaxError`, so does Hy; same for `TypeError`s.
Multiple tests have been added that check the format and type of raised
exceptions over varying command-line invocations (e.g. interactive and not).
A new exception type for `require` errors was added so that they can be treated
like normal run-time errors and not compiler errors.
The Hy REPL has been further refactored to better match the class-structured
API. Now, different error types are handled separately and leverage more base
class-provided functionality.
Closeshylang/hy#1486.
Colored exception output is now disabled by default and configurable through
`hy.errors._hy_colored_errors` and the environment variable
`HY_COLORED_ERRORS`.
Likewise, Hy model/AST color printing is now configurable and disabled by
default. The corresponding variables are `hy.models._hy_colored_ast_objects`
and `HY_COLORED_AST_OBJECTS`.
Closeshylang/hy#1429, closeshylang/hy#1510.
These changes make the Hy REPL more closely follow `code.InteractiveConsole`'s
class interface and provide minimally intrusive traceback print-out filtering
via a context manager that temporarily alters `sys.excepthook`. In other words,
exception messages from the REPL will no longer show Hy internal
code (e.g. importer, compiler and parsing functions).
The boolean variable `hy.errors._hy_filter_internal_errors` dynamically
enables/disables trace filtering, and the env variable
`HY_FILTER_INTERNAL_ERRORS` can be used as the initial value.
This commit refactors the exception/error classes and their handling.
It also retains Hy source strings and their originating file information, when
available, all throughout the core parser and compiler functions.
As well, with these changes, calling code is no longer responsible for providing
source and file details to exceptions,
Closeshylang/hy#657.
Previously, Hy scripts that raised a subclass of IOError would be caught
by code intended to deal with IOErrors raised when Hy couldn't import
the script itself, resulting in either a misleading "Can't open file"
error message, or a misleading TypeError traceback from not being able
to format the "Can't open file" message (for IOErrors for which the
errno attribute was None). This commit (a straightforward implementation
of the idea proposed by @slimetree in #714) introduces a new HyIOError
class, raises that when `import_file_to_hst` can't open the file path,
and catches it in the `cmdline_handler`.
This is believed to fix#513, #714, and #727.
This version is much simpler.
At the point that the exception is raised, we don't have access to
the actual source, just the current expression. but as the
exception percolates up, we can intercept it, add the source and
the re-raise it.
Then at the final point, in the cmdline handler, we can choose to
let the entire traceback print, or just the simpler, direct error
message.
And even with the full traceback, the last bit is nicely formatted
just like the shorter, simpler message.
The error message is colored if clint is installed, but to avoid
yet another dependency, you get monochrome without clint.
I'm sure there is a better way to do the markup, the current method
is kludgy but works.
I wish there was more shared code between HyTypeError and LexException
but they are kind of different in some fundamental ways.
This doesn't work (yet) with runtime errors generated from Python,
like NameError, but I have a method that can catch NameError and turn it
into a more pleasing output.
Finally, there is no obvious way to raise HyTypeError from pure Hy code,
so methods in core/language.hy throw ugly TypeError/ValueError.
Kodi Arfer