worddiff

Documentation

Overview

Package worddiff provides intra-line word-diff algorithms and a shared text-range highlight insertion engine. It owns tokenization, LCS computation, byte-offset range building, similarity gating, and line pairing for add/remove diff blocks.

The public API is exposed as methods on the stateless Differ type, enabling consumer-side interface wrapping in the ui package (same pattern as style.SGR).

Index

• type Differ
  • func New() *Differ
  • func (d *Differ) ComputeIntraRanges(minusLine, plusLine string) ([]Range, []Range)
  • func (d *Differ) InsertHighlightMarkers(s string, matches []Range, hlOn, hlOff string) string
  • func (d *Differ) PairLines(lines []LinePair) []Pair
• type LinePair
• type Pair
• type Range

Types

type Differ

type Differ struct{}

Differ provides intra-line word-diff algorithms and highlight marker insertion. stateless — the receiver carries no mutable state. exists to group related methods under a type for consumer-side interface wrapping (same pattern as style.SGR).

func New

func New() *Differ

New returns a Differ. the constructor exists for consistency with the DI pattern (main.go calls worddiff.New() and injects into ModelConfig).

func (*Differ) ComputeIntraRanges

func (d *Differ) ComputeIntraRanges(minusLine, plusLine string) ([]Range, []Range)

ComputeIntraRanges computes changed byte-offset ranges for a pair of minus/plus lines. returns ranges for the minus line and plus line respectively. returns nil ranges if either line is empty, exceeds maxLineLenForDiff, or fails the similarity gate (< 30% common non-whitespace tokens).

func (*Differ) InsertHighlightMarkers

func (d *Differ) InsertHighlightMarkers(s string, matches []Range, hlOn, hlOff string) string

InsertHighlightMarkers walks the string inserting hlOn/hlOff ANSI sequences at match positions, skipping over existing ANSI escape sequences to preserve them. tracks background ANSI state so that match-end restores to the correct bg (e.g. word-diff bg) rather than always using the static hlOff (line bg). when the input has no bg sequences (word-diff caller), restoreBg stays at hlOff and behavior is unchanged.

func (*Differ) PairLines

func (d *Differ) PairLines(lines []LinePair) []Pair

PairLines pairs remove and add lines within a contiguous change block. equal-length runs pair 1:1 in order. unequal runs use greedy best-match scoring. the indices in the returned Pair values are indices into the input lines slice.

type LinePair

type LinePair struct {
	Content  string
	IsRemove bool
}

LinePair represents a line of content with its change direction for pairing.

type Pair

type Pair struct {
	RemoveIdx int
	AddIdx    int
}

Pair represents a matched pair of remove/add line indices for intra-line diffing.

type Range

type Range struct {
	Start int // byte offset of range start
	End   int // byte offset past last byte
}

Range represents a byte-offset range in a text line. used for both intra-line word-diff highlighting and search match highlighting.