message: make alignment errors more descriptive
diff: @@ -74,7 +74,7 @@ function seedAlignment(query: string, ref: string): SeedAlignment {
  if (seedMatches.length < 2) {
  // TODO: throw concrete instances of errors, catch and diasplay in the UI
  - throw new Error(`alignPairwise: unable to align`)
  + throw new Error(`alignPairwise: unable to find seed matches`)
  }
  // given the seed matches, determine the maximal and minimal shifts
  @@ -271,7 +271,9 @@ export function alignPairwise(query: string, ref: string): Alignment {
  const { bandWidth, meanShift } = seedAlignment(query, ref)
  if (bandWidth > 400) {
  // TODO: throw concrete instances of errors, catch and diasplay in the UI
  - throw new Error(`alignPairwise: unable to align -- too many gaps`)
  + throw new Error(
  + `alignPairwise: unable to align -- too many insertions/deletions, duplications, or ambiguous seed matches`,
  + )
  }
  const { paths, scores } = scoreMatrix(query, ref, bandWidth, meanShift)
  