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The PatternPack

The three mains in the package:

compileM for compiling the regular expression (s-parameter) to a syntax three of RE_ELEM objects

procedure compileM(ptc:in out Pattern_AC;s : CFix;urv:RangeVectorPack.Map_TY.Map:=RangeVectorPack.Map_TY.Empty_Map);
function compileM(s : CFix;urv:RangeVectorPack.Map_TY.Map:=RangeVectorPack.Map_TY.Empty_Map) return Pattern_AC;

compileU for compiling the regular expression (s-parameter) to a syntax three of RE_ELEM objects but after converting data to upper case, alltough the s-parameter is input only and the conversion is done only internally.

procedure compileU(ptc:in out Pattern_AC;s : CFix;urv:RangeVectorPack.Map_TY.Map:=RangeVectorPack.Map_TY.Empty_Map);
function compileU(s : CFix;urv:RangeVectorPack.Map_TY.Map:=RangeVectorPack.Map_TY.Empty_Map) return Pattern_AC;

function matches(pattern:Pattern_AC;startPos:Integer;nextPos:out Integer;c4match : CFix;match: out MatchPack.Match_TY;squ:Integer:=0) return Boolean;

Two versions for the compilation, one as a procedure call and the second as a function. The declaration of the package in the ads-file y2018.text.jets.patternpack.html.
Function matches is a wrapper for Matchpack for retreiving the results to the Patternpack object.

Example when using the procedure approach ExPsi.adb. The code in ExPsi.adb must be precompiled and compiled.
Comments about the code in ExPsi.adb:

Line 019 : call of compileM - we do not use the 'uppercase' version
Line 020 : match the text "ExPsi procedure" (sourcevalue).
line 022 : create the result array 'r' (I_A_ARRAY(0 .. MatchPack.size(m) - 1);)
line 024 : initiate 'r' array from the variable 'm'

Example when using the function approach ExYpsilon.adb. The code in ExYpsilon.adb must be precompiled and compiled.
Comments about the code in ExYpsilon.adb:

Line 010 : call of compileM - we do not use the 'uppercase' version
Line 017 : match the text "Huey, Dewey, Louie, Duck" (line).
line 019 : create the result array 'r' (I_A_ARRAY:=MatchPack.getMatch(m);)

A shorter version ?

What is this default "urv:RangeVectorPack.Map_TY.Map:=RangeVectorPack.Map_TY.Empty_Map" ? It says that extending of the '\p' is not used in this compilation, only 'mapPool' which is used is the default with General categories and \d \D, \s \S and \w \W .

What is "squ" ?

function matches(pattern:Pattern_AC;startPos:Integer;nextPos:out Integer;c4match : CFix;match: out MatchPack.Match_TY;squ:Integer:=0) return Boolean;
In some cases the pattern of a regular expression can still be fit if we decrease found codepoints where a variable amount. Value squ (short for squeeze) says the amount of times we can try. The fitting process is experimental form of backtracking but can be useful.
As an example see ExLamda. In this case we squeeze the value of r(1) with one for a value in r(2), the digit '9'.