Evaluate sexp before point; print value in minibuffer.
Interactively, with prefix argument, print output into current buffer.
Truncates long output according to the value of the variables
`eval-expression-print-length' and `eval-expression-print-level'.
If `eval-expression-debug-on-error' is non-nil, which is the default,
this command arranges for all errors to enter the debugger.