Add .S to core words

[MaxBarraclough]

The .S word is defined in calc.f as:

: .S
 ." STACK: "
  DEPTH 15 AND DUP
  IF DUP 0 DO DUP PICK U. 1- LOOP DROP
  ELSE DROP ." <EMPTY>" THEN CR
;

This works nicely, I suggest it be made available 'out of the box', as it's convenient for interactive use.

[ruv]

In SP-Forth/4, not all standard words are included in the kernel. Some of them are provided in source code files in lib/include/ subdirectory (see also "ANS support" section of the manual in docs/intro.en.md). The word .S is provided in lib/include/tools.f, all the standard words (except locals) can be included via lib/include/ansi.f.

Formally, such approach is allowed by the standard, as the section "3 Usage requirements" says:

A system need not provide all words in executable form. The implementation may provide definitions, including definitions of words in the Core word set, in source form only. If so, the mechanism for adding the definitions to the dictionary is implementation defined.

Nevertheless, the next release plans to provide two binaries — one minimal and one extended with all the standard words and case insensitivity mode by default.

[MaxBarraclough]

I see, thanks for the reply. I suggest mentioning the following in the README.md to make it easier for dabblers exploring SP-Forth.

S" lib/include/ansi.f" INCLUDED