* gash/arithmetic.scm: New file.
* Makefile.am (SOURCES): Add it.
* gash/lexer.scm (get-arithmetic-expansion): New procedure.
(get-expansion): Check for "$((" and use the new procedure to read an
arithmetic expansion.
* gash/eval.scm (word->qword): Handle '<sh-arithmetic>'.
* tests/unit/eval.scm: Add tests.
* tests/spec/Makefile.am (TESTS): Add 'arith'.
* tests/spec/oil.scm: Patch seven of its tests and filter out fifteen
others.
* doc/gash.texi, doc/syntax.txt: Add '<sh-arithmetic>' syntax.
* doc/gash.texi: Add an introduction, add a discussion of included and
missing features, document the parser interface, and remove the
indexes.
* doc/syntax.txt: Update to match the manual.
The AST generated by the parser did not match the syntax document.
However, neither were right. This commit updates the syntax document
to describe a more consistent form, and fixes the code to follow it.
* doc/syntax.txt (word): Make the children of '<sh-cmd-sub>' a
possibly empty list of 'list's.
* geesh/lexer.scm (get-bracketed-command): Splice in children for
'<sh-cmd-sub>'.
(get-backquoted-command): Ditto.
* geesh/parser.scm (read-sh/bracketed): Make sure that result is
always a list.
(read-sh/backquoted): Ditto.
* tests/lexer.scm: Update tests accordingly.
* tests/parser.scm: Ditto.
Timothy Sample