Rewrite the parsing loop using one single regular expression to match…

… all active macros

The object has a stack of current parsers, using the parser at the top of the stack.
This allows different parsers to be used e.g. to match text with macros to be expanded,
and to extract macro parameters from the input text.

The main parser is built around one single regular expression that matches all macros,
scripts and variables and definition statements. This regular expression is extended each time
a new macro/variable/script is defined.

Module not yet fully functional, only %DEFINE_VARIABLE implemented.

New test files prefixed with new_, as all the old test cases will fail until the implementation
is complete.

- Fix #7: expansion depends on size of script name
  The regular expression matches first the longer macros/variables/scripts.

- Fix #2: expand() does not accept a multi-line text
  Allow the multi-line definitions to be split across different input lines, and more than
  one definition on the same line.

- Fix #28: #varname syntax should be accepted in both scripts and macros
  Fix #37: Variables should be expanded in all input text, not only in macro scripts
  Fix #38: Variables with # syntax not parsed by $Macro->define()
  Allow variables to be expanded anywhere in the input by the sequence #VARNAME, and
  not only within scripts.

- Fix #40: Variables should accept expressions and compute them
  Allow perl expressions in the definition of variables, that are computed before storing
  the result in the variable, e.g. "%DEFINE_VARIABLE NAME [uc('#name')]".

- Fix #41: Macro/script arguments do not nest
  Parser of macro arguments counts the number of unescaped '[' and ']' stopping when the
  initial '[' is matched by a corresponding ']', allowing calls like
  "ADD[ADD1[ADD2[ADD3[4]]] | 10])"

- Allow variables to be computed based on their previous value, allowing for example a
  variable to be incremented by "%DEFINE_VARIABLE X [#X+1]".

- Implement escaping of special characters ([ | ] # %) by preceding them with back-slash,
  so that "\#varname" is expanded to "#varname".

- Simplify test scripts
  No need to include Test::Differences in every test script, as it is
  included in mytests.pl

- Update documentation

Makefile.PL

@@ -23,6 +23,7 @@ WriteMakefile(
             AUTHOR   => 'Mark Summerfield <summer@perlpress.com>',
         ) : () ),
 	'PREREQ_PM'	   => {
+		'enum'				=> 1.10,
 		'Path::Tiny'		=> 0.068,
 		'Capture::Tiny'		=> 0.22,
 		'Test::Differences'	=> 0.61,

t/expand_file.t

@@ -9,7 +9,6 @@ use strict;
 use warnings;
 use Capture::Tiny 'capture';
 use Path::Tiny;
-use Test::Differences;
 use Test::More;
 
 use_ok 'Text::MacroScript';

t/macrodir.t

@@ -6,7 +6,6 @@
 use strict;
 use warnings;
 use Test::More;
-use Test::Differences;
 use Capture::Tiny 'capture';
 use Path::Tiny;
 use Time::HiRes 'usleep';

t/macropp.t

@@ -6,7 +6,6 @@
 use strict;
 use warnings;
 use Test::More;
-use Test::Differences;
 use Capture::Tiny 'capture';
 use Path::Tiny;
 

t/macros.t

@@ -6,7 +6,6 @@
 use strict;
 use warnings;
 use Capture::Tiny 'capture';
-use Test::Differences;
 use Test::More;
 
 my $ms;

t/mytests.pl

@@ -5,6 +5,7 @@
 
 use strict;
 use warnings;
+use Test::Differences;
 
 # normalize output and expected strings before eq test
 sub _normalize_expected {

t/new.t

@@ -8,7 +8,6 @@ use warnings;
 use Capture::Tiny 'capture';
 use Path::Tiny;
 use POSIX 'strftime';
-use Test::Differences;
 use Test::More;
 
 use_ok 'Text::MacroScript';

t/new_define_embedded.t

@@ -0,0 +1,46 @@
+#!/usr/bin/perl
+
+# Copyright (c) 2015 Paulo Custodio. All Rights Reserved.
+# May be used/distributed under the GPL.
+
+use strict;
+use warnings;
+use Test::More;
+use Data::Dump 'dump';
+
+my $ms;
+use_ok 'Text::MacroScript';
+require_ok 't/mytests.pl';
+
+sub void(&) { $_[0]->(); () }
+
+# escapes and concat
+$ms = new_ok('Text::MacroScript', [-embedded => 1]);
+is $ms->expand(), "";
+is $ms->expand("hello"), "hello";
+
+is $ms->expand("hello \\\n world"), "hello \\\n world";
+is $ms->expand("hello \\% world"), "hello \\% world";
+is $ms->expand("hello \\# world"), "hello \\# world";
+is $ms->expand("hello ## world"), "hello ## world";
+
+is $ms->expand("hello <:\\\n:> world"), "hello   world";
+is $ms->expand("hello <:\\% world"), "hello % world";
+is $ms->expand("hello \\# :>world"), "hello # world";
+is $ms->expand("<:hello ## :>world"), "helloworld";
+
+# variable expansion
+$ms = new_ok('Text::MacroScript', [-embedded => 1]);
+is $ms->expand("abc<:%DEFINE_VARIABLE*HELLO*[1+]:>def"), "abcdef";
+is $ms->expand("<:#*HELLO*:>"), "1+";
+is $ms->expand("<:#*HELL:><:O*:>"), "#*HELLO*";
+
+# multiple line value and counting of []
+$ms = new_ok('Text::MacroScript', [-embedded => 1]);
+is $ms->expand("a<:%DEFINE_VARIABLE X [:>b"), "ab";
+is $ms->expand("c<:[hello:>d"), "cd";
+is $ms->expand("e<:|:>f"), "ef";
+is $ms->expand("g<:world]:>h"), "gh";
+is $ms->expand("i<:]:>j<:#X:>k"), "ij[hello|world]k";
+
+done_testing;

t/new_define_variable.t

@@ -0,0 +1,92 @@
+#!/usr/bin/perl
+
+# Copyright (c) 2015 Paulo Custodio. All Rights Reserved.
+# May be used/distributed under the GPL.
+
+use strict;
+use warnings;
+use Test::More;
+
+my $ms;
+use_ok 'Text::MacroScript';
+require_ok 't/mytests.pl';
+
+# API call
+$ms = new_ok('Text::MacroScript');
+$ms->define_variable('X', 123);
+is $ms->expand("#X"), "123";
+
+$ms->define(-variable, 'X', 321);
+is $ms->expand("#X"), "321";
+
+# escapes and concat
+$ms = new_ok('Text::MacroScript');
+is $ms->expand(), "";
+is $ms->expand("hello"), "hello";
+is $ms->expand("hello \\\n world"), "hello   world";
+is $ms->expand("hello \\% world"), "hello % world";
+is $ms->expand("hello \\# world"), "hello # world";
+is $ms->expand("hello ## world"), "helloworld";
+
+# syntax errors
+$ms = new_ok('Text::MacroScript');
+eval {$ms->expand("%DEFINE_VARIABLE")};
+is $@, "Error at file - line 1: Expected NAME [EXPR]\n";
+
+$ms = new_ok('Text::MacroScript');
+eval {$ms->expand("%DEFINE_VARIABLE", "file.asm", 10)};
+is $@, "Error at file file.asm line 10: Expected NAME [EXPR]\n";
+
+$ms = new_ok('Text::MacroScript');
+eval {$ms->expand("%DEFINE_VARIABLE*HELLO*")};
+is $@, "Error at file - line 1: Expected NAME [EXPR]\n";
+
+$ms = new_ok('Text::MacroScript');
+$ms->expand("%DEFINE_VARIABLE*HELLO*[");
+eval { $ms->DESTROY };
+is $@, "Error at file - line 1: Unbalanced open structure at end of file\n";
+
+$ms = new_ok('Text::MacroScript');
+eval { $ms->expand("%DEFINE_VARIABLE*HELLO*[1|2]") };
+is $@, "Error at file - line 1: Only one argument expected\n";
+
+$ms = new_ok('Text::MacroScript');
+eval { $ms->define(-xxx, "xxx", "ZZZ") };
+check_error(__LINE__-1, $@, "-xxx method not supported __LOC__.\n");
+
+# variable expansion
+$ms = new_ok('Text::MacroScript');
+is $ms->expand(" %DEFINE_VARIABLE*HELLO*[1+]"), "";
+is $ms->expand("*HELLO*"), "*HELLO*";
+is $ms->expand("#*HELLO"), "#*HELLO";
+is $ms->expand("#*HELLO*"), "1+";
+is $ms->expand("\\#*HELLO*"), "#*HELLO*";
+is $ms->expand("#*HELLO*#*HELLO*"), "1+1+";
+is $ms->expand("#*HELLO* ## #*HELLO*"), "1+1+";
+
+# arithmetic expressions
+is $ms->expand("%DEFINE_VARIABLE*HELLO*[1+2]#*HELLO*"), "3";
+
+# perl expressions
+is $ms->expand("%DEFINE_VARIABLE hello [ola]#hello"), "ola";
+is $ms->expand("%DEFINE_VARIABLE HELLO [uc('#hello')]#HELLO"), "OLA";
+
+# self referencing variable
+is $ms->expand("%DEFINE_VARIABLEX[#X+1]#X"), "1";
+is $ms->expand("%DEFINE_VARIABLEX[#X+1]#X"), "2";
+is $ms->expand("%DEFINE_VARIABLEX[#X+1]#X"), "3";
+
+# multiple line value and counting of []
+$ms = new_ok('Text::MacroScript');
+is $ms->expand("%DEFINE_VARIABLE X ["), "";
+is $ms->expand("[hello"), "";
+is $ms->expand("|"), "";
+is $ms->expand("world]"), "";
+is $ms->expand("]#X"), "[hello|world]";
+
+# escape [ | ]
+is $ms->expand("%DEFINE_VARIABLE X [a\\[b]#X"), "a[b";
+is $ms->expand("%DEFINE_VARIABLE X [a\\|b]#X"), "a|b";
+is $ms->expand("%DEFINE_VARIABLE X [a\\]b]#X"), "a]b";
+
+done_testing;

t/scripts.t

@@ -6,7 +6,6 @@
 use strict;
 use warnings;
 use Capture::Tiny 'capture';
-use Test::Differences;
 use Test::More;
 
 my $ms;

t/variables.t

@@ -6,7 +6,6 @@
 use strict;
 use warnings;
 use Capture::Tiny 'capture';
-use Test::Differences;
 use Test::More;
 
 use_ok 'Text::MacroScript';