[DERBY-565] Misleading parser diagnostics

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 10.1.1.0
• Component/s: SQL
• Labels: derby_triage10_5_2
• Urgency: Normal
• Assignee: Unassigned
• Reporter: Richard N. Hillegas
• Created: 14/Sep/05 03:23
• Updated: 15/Feb/11 21:09

Description

Bryan Pendleton reports:

When I mistype 'join' as 'joing', the error message that I
get actually complains about the word 'left'. It ought to,
in my opinion, complain about the word 'joing', since that
is truly the word with the syntax error in it.

ij> select * from t1 left outer joing t2 on t1.c2=t2.c1;
ERROR 42X01: Syntax error: Encountered "left" at line 1, column 18.

I don't know if this is a PITA to fix or not, but I thought
I'd send it along anyway since it was so easy to reproduce.

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This appears to be a problem with hand-coded lookahead logic. Although fixing this particular lookahead issue might be trivial, this is part of a larger problem since the parser is liberally peppered with similar hand-coded lookahead logic. Coming up with a general solution might involve some creativity.