Codepoint-based string iterator. More...

#include <cpIter.hpp>

Public Member Functions
	cpIter (const nchar begin, const nchar from)
	Constructs iterator from pointer range.

	cpIter (const std::string &from, nbool isReversed=false)
	Constructs iterator from string reference.

	cpIter (std::string &&from, nbool isReversed=false)=delete

me	operator+ (ncnt step)

me &	operator++ ()

me	operator++ (int)

me &	operator+= (ncnt step)

std::string	operator* () const

	operator nbool () const

nbool	operator== (const me &rhs) const

nbool	isEnd () const

void	rel ()

ncnt	next (ncnt step)
	Advances iterator in its default direction.

ncnt	stepForward (ncnt step)
	Unconditionally advances iterator forward.

ncnt	stepBackward (ncnt step)
	Unconditionally advances iterator backward.

std::string	get () const

ncnt	remainLen () const

Detailed Description

Codepoint-based string iterator.

Handles codepoint-based iteration for strings. Primarily used in nStr for traversing multibyte strings like UTF-8 Unicode.

Like typical iterators, it supports prefix/postfix increment operators, dereference operator, and bool conversion operator. When creating a cpIter, you can specify the string to traverse along with the default iteration direction.

Remarks: Direction and initial position The direction specified during cpIter creation defines the iterator's default direction and initial position. If you pass reverse = true as argument, cpIter starts from the end of the string in reverse direction. However, if you explicitly call stepBackward() or stepForward(), it will move in that direction regardless of the default direction.; Past-the-end semantics Like STL, begin points to the first element, but end points to the position after the last element (past-the-end). Therefore, when traversing in reverse, you must call next() first.

Usage

Basic usage example:

std::string src = "abcd🏁efg"; // In UTF-8, 🏁 is represented by 3 characters
cpIter e4(src, true); // Define default iteration as reverse.
                      // At this point, it points to past-the-end position
while(*e4 != "") // Currently at end position, so "" is returned
    ++e4; // Same as calling e4.next(). Moves in default reverse direction
          // But this code never actually executes
ASSERT_EQ(*e4, "");
 
std::string expects[] = {"g", "f", "e", "🏁", "d", "c", "b", "a"};
for(int n = 0; n < 8; n++) {
    // Explicitly specify direction to traverse iterator.
    // Unconditionally moves backward regardless of e4's direction
    e4.stepBackward(1);
    // For reverse traversal, you must step first
    ASSERT_EQ(*e4, expects[n]);
}

Constructor & Destructor Documentation

◆ cpIter() [1/2]

by::cpIter::cpIter	(	const nchar *	begin,
		const nchar *	from )

Constructs iterator from pointer range.

Note: Direction automatically determined: reverse if begin > from, forward otherwise

◆ cpIter() [2/2]

by::cpIter::cpIter	(	const std::string &	from,
		nbool	isReversed = false )

explicit

Constructs iterator from string reference.

Parameters

from	String must outlive this iterator
isReversed	true for reverse iteration (starts at end), false for forward

Member Function Documentation

◆ next()

ncnt by::cpIter::next ( ncnt step )

Advances iterator in its default direction.

Returns: Actual codepoints moved (may be less if end reached)

Note: Moves forward for forward iterators, backward for reverse iterators

◆ stepBackward()

ncnt by::cpIter::stepBackward ( ncnt step )

Unconditionally advances iterator backward.

Returns: Actual codepoints moved (may be less if beginning reached)

Note: Direction is absolute, unaffected by iterator's reverse flag

◆ stepForward()

ncnt by::cpIter::stepForward ( ncnt step )

Unconditionally advances iterator forward.

Returns: Actual codepoints moved (may be less if end reached)

Note: Direction is absolute, unaffected by iterator's reverse flag

The documentation for this class was generated from the following file:

/home/runner/work/stela/stela/module/indep/helper/cpIter.hpp

Public Member Functions