Get: go on reading the file after a syntax error, as in WMA

[tombouctou]

When Get hits a syntax error, Mathics3 currently prints the message and then stops reading the file. Everything after the error is silently dropped. WMA does not do this. Its reference page says:

Get continues attempting to read a file even after a syntax error has been detected.

A minimal example (test/data/syntax-error-bug.m):

getSyntaxA = 1;
getSyntaxB = \[NoSuchCharacterName];
getSyntaxC = 3;
{getSyntaxA, getSyntaxB, getSyntaxC}

Get on this file currently reports the bad character name and returns Null, so getSyntaxC is never set. With this PR it reports the error, goes on reading, and returns {1, getSyntaxB, 3}.

In older packages, one bad line near the top therefore lost most of the file. For example, a single mistyped \[...] name lost hundreds of definitions that came after it.

The change is in eval_Get. After a SyntaxError, the loop continues with the next statement. As a guard against looping forever, it still returns Null if the parser consumed no input, i.e. the feeder's line number did not advance.

The new test test_get_continues_after_syntax_error fails on master and passes here. It deliberately does not check the text of the syntax message, because that text comes from Mathics3-scanner.

🤖 Generated with Claude Code

[rocky]

I'd appreciate it if we could change the extension here to end in .wl. The problem with .m extensions is that Objective-C headers also have an .m extension. Using .wl at the end, though, is unambiguously Wolfram Alpha as far as I can tell.

[tombouctou]

Done in 1f544ac: the file is now test/data/syntax-error-bug.wl; nothing else changes. Most of the other files in test/data/ (script.m, input-bug.m, star-bug.m, …) are still .m. If you'd like, I can rename those in a separate PR.

[rocky]

Many thanks! Yes, I'd be grateful if you'd rename the others in a separate PR.

[rocky]

LGTM