begin refactoring parse tree evaluator * libinterp/parse-tree/pt-tm-const.cc, libinterp/parse-tree/pt-tm-const.h: New files, extracted from pt-mat.h and pt-mat.cc. * libinterp/parse-tree/module.mk: Update. * interpreter.cc, ov-class.cc, ov-classdef.cc, ov-classdef.h, ov-fcn-handle.cc, ov-fcn-handle.h, ov-usr-fcn.cc, oct-parse.in.yy, pt-arg-list.cc, pt-arg-list.h, pt-array-list.h, pt-assign.cc, pt-assign.h, pt-binop.cc, pt-binop.h, pt-cbinop.cc, pt-cbinop.h, pt-cell.cc, pt-cell.h, pt-classdef.cc, pt-classdef.h, pt-cmd.cc, pt-cmd.h, pt-colon.cc, pt-colon.h, pt-const.cc, pt-const.h, pt-decl.cc, pt-decl.h, pt-eval.cc, pt-eval.h, pt-except.cc, pt-except.h, pt-exp.cc, pt-exp.h, pt-fcn-handle.cc, pt-fcn-handle.h, pt-funcall.cc, pt-funcall.h, pt-id.cc, pt-id.h, pt-idx.cc, pt-idx.h, pt-jit.cc, pt-jump.cc, pt-jump.h, pt-loop.cc, pt-loop.h, pt-mat.cc, pt-mat.h, pt-misc.cc, pt-misc.h, pt-select.cc, pt-select.h, pt-stmt.cc, pt-stmt.h, pt-unop.cc, pt-unop.h: Use tree_evaluator class to walk the parse tree instead of rvalue methods in the parse tree classes. Maintain a stack in the evaluator class to accumulate results. Pass pointer to evaluator to function objects and other classes as needed for evaluation. This is a work in progress that is not yet complete. The ultimate goal is to move all evaluation into the tree_evaluator class instead of spreading that work among many different classes. The global pointer to the current evaluator should also be eliminated.

6841b128619d026dc2d147c65a2d34918c2b272f gnulib