xbScript

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.

1. 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).

2. 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.

3. 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 ... )