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Chapter9 L.O.V.E. FORTH
9.0 Working In L.O.V.E. Forth
-------------------------
Here are some notes on how to do day-to-day work in L.O.V.E.
Forth. A good starting point for viewing the features is given in the
shareware demo LOVES.EXE .
9.1 Help
----
For help while using the system, load the Hyper Helper with the DOS
command: HM LOVE before running Forth. Or execute GO.BAT or
MIN.BAT . The help system is subsequently invoked with the key sequence:
HELP or HELP forth word, eg help loop .
9.2 Directories
-----------
Usually, the programmer copies Forth to the working directory,
including source code etc. When copying the EXE to another directory, be
sure to also copy the *.VTR files. These are the virtual vocabularies.
Alternatively, the DOS APPEND command can be used to direct DOS to
the appropriate directory.
9.3 Versions of L.O.V.E. Forth
--------------------------
The minimum system, with the smallest number of features compiled
is called MINnnn.EXE, where nnn is the version number (eg. MIN129.EXE ).
This is the program executed by MIN.BAT . On top of this can be the
block disk words (LOADBLK.TXT) and / or the RPN assembler. Be sure to
save the system again with SAVE" after loading the desired features
(eg. SAVE" LOVERPN.EXE" ).
Various source code modules can be loaded on top of the minimum
system. These include local variables, multiple CFA words,
miscellaneous words. Dependancies:
LOADBLK.TXT also loads MISC.TXT
ARRAY.TXT requires MCFA.TXT
All others can be loaded independently.
9.4 Upper and Lower Case
--------------------
Normally, the case of a word is ignored. By setting variable
CASEMATCH to true, however, will cause L.O.V.E. Forth to match the case
of the word as it originally was compiled. All the L.O.V.E. Forth standard
words were compiled in upper case. Compilation is slightly faster in case
match mode, but it is usually desireable to type interactive commands with
case ignored.
9.5 Text strings
------------
Frequently the programmer requires control characters in strings.
This is difficult to do in any text file, as control characters may be
editor commands, or printer control codes. L.O.V.E. Forth supports AWK
style escape commands. These are summarized as follows:
\b : backspace
\f : formfeed
\n : newline, linefeed
\r : carriage return
\t : tab
\ddd : decimal value, 1 to 3 digits
\c : where 'c' is any other character literally
\\ : for backslash
\" : for "
These can be used in text strings compiled with the words:
." " ," .(
9.6 Vocabularies
------------
See also the section describing vocabularies. The usual vocabulary
for working in Forth is FORTH. The words controlling the dictionary search
order are in vocabulary ROOT . The word DEVELOP sets the search order
to be ROOT FORTH and TOOLBOX which contains programming aids.
The vocabulary implementation is that of a stack, ALSO pushes the stack
and VDROP drops the top of the stack. ONLY resets it to ROOT only.
9.7 Access to DOS
-------------
Typing the word DOS followed by a DOS command line, executes that
in a DOS shell. Typing DOS followed by nothing, enters the DOS shell
(typing EXIT returns to Forth). This is one way to invoke a text editor.
Note that there must be enough memory to invoke DOS. If too much memory is
allocated in MAXHEAP (see instructions on saving the system), DOS
cannot be entered.
9.8 Windows 3.0/3.1
---------------
The multitasking features of this environment are useful. One can
run L.O.V.E. Forth from a DOS prompt, and have an editor running in another
window. The L.O.V.E. Forth icon is provided.