Overview of Segment Traversal Functions

Table of Contents

• Function Categories
  • Element-wise vs. Segment-wise Traversal
  • Scope and Conditional Variants
• Element-wise Traversal Functions
  • Basic Element Traversal
• Segment-wise Traversal Functions
  • Basic Segment Traversal
• Common Parameters
• Related Pages

This page provides an overview of all traversal functions available for segment operations, helping to understand the differences between variants and choose the right function for your needs.

Function Categories

Traversal functions are organized along two main dimensions:

Element-wise vs. Segment-wise Traversal

Category	Operates On	Lambda Parameter	Use Case
Element-wise (forElements, forAllElements)	Individual elements	Element indices	Operate on each element separately
Segment-wise (forSegments, forAllSegments)	Whole segments	SegmentView object	Operate on segments as units

When to use:

• Element-wise: When you need to process each element independently (e.g., apply transformation, update values)
• Segment-wise: When you need access to the entire segment structure or segment context (e.g., custom segment algorithms, segment-level operations)

Scope and Conditional Variants

Similar to other segment operations, traversal functions come in different scopes and conditional variants.

Scope	Segments Processed	Parameters
All	All segments	No range/array parameters
Range	Segments [begin, end)	begin and end indices
Array	Specific segments	Array of segment indices
If	Segment condition	Process segments based on segment-level properties

Element-wise Traversal Functions

These functions iterate over individual elements within segments:

Basic Element Traversal

Function	Segments Processed	Description
forAllElements	All segments	Process all elements in all segments
forElements (range)	Segments [begin, end)	Process elements in segment range
forElements (array)	Segments in array	Process elements in specified segments
forAllElementsIf	All segments	Segment-level condition
forElementsIf	Segments [begin, end)	Segment-level condition

Segment-wise Traversal Functions

These functions iterate over segments as whole units:

Basic Segment Traversal

Function	Segments Processed	Description
forAllSegments	All segments	Process all segments
forSegments (range)	Segments [begin, end)	Process segments in range
forSegments (array)	Segments in array	Process specified segments
forAllSegmentsIf	All segments	Segment-level condition
forSegmentsIf	Segments [begin, end)	Segment-level condition

Common Parameters

All traversal functions share these common parameters:

• segments: The segments container to traverse
• f: Lambda function to apply (see Full Form (With All Parameters), Brief Form (Without Local Index), or Segment View Lambda)
• launchConfig: Configuration for parallel execution (optional)

Additional parameters for specific variants:

• Scope variants: begin, end (range) or segmentIndexes (array)
• If variants: condition lambda for filtering (see Condition Check)

Related Pages

• Segment Traversal Lambda Function Reference - Detailed lambda function signatures
• TNL::Algorithms::Segments::SegmentView - Segment view documentation