Various kinds of printer functions (SES: Simple Emacs Spreadsheet)

When configuring what printer function applies (see Configuring what printer function applies), you can enter a printer function as one of the following:

A format string, like ‘"$%.2f"’. The result string is right-aligned within the print cell. To get left-alignment, use parentheses: ‘("$%.2f")’.
A printer can also be a one-argument function, the result of which is a string (right-aligned) or list of one string (left-aligned). Such a function can be in turn configured as:
- A lambda expression, for instance:
```
(lambda (x)
  (cond
     ((null x) "")
     ((numberp x) (format "%.2f" x))
     (t (ses-center-span x ?# 'ses-prin1))))
```
  While typing in a lambda, you can use M-TAB to complete the names of symbols.
- A symbol referring to a standard printer function (see Standard printer functions).
- A symbol referring to a local printer function (see Local printer functions).