xbScript is an xBase language (dBase/FoxPro/Clipper/[x]Harbour Interpreter, implemenmted in the Clipper/Harbour/xHarbour dialects - including a complete Clipper Pre-Processor (supporting the [x]Harbour extensions.
The implementation is mostly contained in a single PRG source file (pp.prg - as it started as a Pre-Processor implementation and later grew to a full interpreter and a complete DOT Prompt/Run-Time Environment).
You can build it using Clipper/Harbour/xHarbour and probably using Xbase++ and other Clipper clones/supersets.
Command line switches and syntax.
PP filename[.ext] [-CCH] [-D] [-D:E] [-D:M] [-D:P] [-H] [--help][-I] [-P] [-R] [-STRICT] [-U[]]
-CCH = Generate a .cch file (compiled command header).
-D<id> = #define <id>.
-D:E = Show tracing information into the Expression Scanner.
-D:M = Show tracing information into the Match Engine.
-D:P = Show tracing information into the Output Generator.
-H = Syntax and command line switches description.
--help = Syntax and command line switches description.
-I<path> = #include file search path(s) (';' seperated).
-P = Generate .pp$ pre-processed output file.
-R = Run filename as a script.
-STRICT = Strict Clipper compatability (clone Clipper PreProcessor bugs).
-U = Use command definitions set in <ch-file> (or none).
PP has 3 personalities which are tied tightly together.
-
What is supposed to be 100% Clipper compatible Pre-Processor (with some extensions).
Executing PP followed by a source file name and the -P switch, will create <filename.pp$> which is the equivalent of the Clipper <filename.ppo> file.
This syntax is:
PP filename[.ext] -P
In this mode these are the optional command line switches.
-CCH = Generate a .cch file (compiled command header). -D = #define . -D:E = Show tracing information into the Expression Scanner. -D:M = Show tracing information into the Match Engine. -D:P = Show tracing information into the Output Generator. -I = #include file search path(s) (';' separated). -STRICT = Strict Clipper compatability (clone Clipper PreProcessor bugs). -U = Use command definitions set in (or none).
-
DOT prompt, which allows most of the Clipper syntax. Please report any syntax you expect to work, but is not supported.
It does support IF [ELSE] [ELSEIF] ENDIF in DOT environment.
Executing PP with no source filename will start the DOT prompt mode.
In this mode you can execute a single line at a time by typing the line and pressing the [Enter] key.
Additionally you may type:
DO filename.prg [Enter]
So that DOT will "run" the specified source file. This interpreter mode is subject to few limitations:
a. It does support LOCAL/STATIC/PRIVATE/PUBLIC, but:
- STATICs are actually implemented as publics. - LOCALS have scoping of locals but are implemented as privates so you can't have a LOCAL and a PRIVATE with the same name.b. Non-declared variables are auto-created on assignment in Harbour but NOT in Clipper (yet).
c. It does support definition and execution of prg-defined FUNCTIONs/PROCEDUREs.
d. It does support ALL control flow structures except BEGIN SEQUENCE [BREAK] [RECOVER] END SEQUENCE.
e. The executed module is compiled with -n option (for now).
This will create rp_dot.pp$ compilation trace file.
-
Finally, PP is a limited Clipper/Harbour/xBase Interpreter. Subject to those same few limitations it can execute most of Harbour syntax. Executing PP followed by a source file name and the -R switch will "RUN" that source (it will also create the rp_run.pp$ compilation trace file).
This syntax is:
PP filename[.ext] -R
In this mode these are the optional command line switches.
-CCH = Generate a .cch file (compiled command header). -D = #define . -D:E = Show tracing information into the Expression Scanner. -D:M = Show tracing information into the Match Engine. -D:P = Show tracing information into the Output Generator. -I = #include file search path(s) (';' separated). -P = Generate .pp$ pre-processed output file. -STRICT = Strict Clipper compatability (clone Clipper PreProcessor bugs). -U = Use command definitions set in (or none).
a. It does support LOCAL/STATIC/PRIVATE/PUBLIC, but:
- STATICs are actually implemented as publics. - LOCALS have scoping of locals but are implemented as privates so you can't have a LOCAL and a PRIVATE with the same name.b. Non-declared variables are auto-created on assignment in Harbour but NOT in Clipper (yet).
c. It does support definition and execution of prg-defined FUNCTIONs/PROCEDUREs as well as parameter passing and return values.
d. It does support ALL control flow structures except BEGIN SEQUENCE [BREAK] [RECOVER] END SEQUENCE.
e. The compiled module is automatically using -n (No implicit startup procedure) if the script starts with a Procedure/Function definition.
f. Built-in OLE COM Client gateway is included when PP is compiled with Harbour and using -dWIN (harbour pp -dWIN -w ... )