Method segmentTo

src/utils/textHighlighting.ts:97–162

(targetVisiblePos: number)

  }

  private segmentTo(targetVisiblePos: number): TextSegment | null {
    if (
      this.tokenIdx >= this.tokens.length ||
      targetVisiblePos <= this.visiblePos
    ) {
      return null
    }

    const visibleStart = this.visiblePos

    // Consume leading ANSI codes before first visible char
    while (this.tokenIdx < this.tokens.length) {
      const token = this.tokens[this.tokenIdx]!
      if (token.type !== 'ansi') break
      this.codes.push(token)
      this.stringPos += token.code.length
      this.tokenIdx++
    }

    const stringStart = this.stringPos
    const codesStart = [...this.codes]

    // Advance through tokens until we reach target
    while (
      this.visiblePos < targetVisiblePos &&
      this.tokenIdx < this.tokens.length
    ) {
      const token = this.tokens[this.tokenIdx]!

      if (token.type === 'ansi') {
        this.codes.push(token)
        this.stringPos += token.code.length
        this.tokenIdx++
      } else {
        const charsNeeded = targetVisiblePos - this.visiblePos
        const charsAvailable = (token as Char).value.length - this.charIdx
        const charsToTake = Math.min(charsNeeded, charsAvailable)

        this.stringPos += charsToTake
        this.visiblePos += charsToTake
        this.charIdx += charsToTake

        if (this.charIdx >= (token as Char).value.length) {
          this.tokenIdx++
          this.charIdx = 0
        }
      }
    }

    // Empty segment (can occur when only trailing ANSI codes remain)
    if (this.stringPos === stringStart) {
      return null
    }

    const prefixCodes = reduceCodes(codesStart)
    const suffixCodes = reduceCodes(this.codes)
    this.codes = suffixCodes