TableFun.join/merge: optimize the important special case where the tables coincide -- NOTE: this changes both the operational behaviour and the result for non-standard join/eq notion;
syntax: glob
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*.class
*.jar
.DS_Store
syntax: regexp
^heaps/
^browser_info/
^doc-src/.*\.aux
^doc-src/.*\.bbl
^doc-src/.*\.blg
^doc-src/.*\.dvi
^doc-src/.*\.idx
^doc-src/.*\.ind
^doc-src/.*\.log
^doc-src/.*\.out
^doc-src/.*\.rai
^doc-src/.*\.rao
^doc-src/.*\.toc