private boolean castEqual()

in exec/java-exec/src/main/java/org/apache/drill/exec/expr/ExpressionTreeMaterializer.java [961:1016]
46 lines of code
36 McCabe index (conditional complexity)

    private boolean castEqual(ExpressionPosition pos, MajorType from, MajorType to) {
      if (!from.getMinorType().equals(to.getMinorType())) {
        return false;
      }
      switch(from.getMinorType()) {
      case FLOAT4:
      case FLOAT8:
      case INT:
      case BIGINT:
      case BIT:
      case TINYINT:
      case SMALLINT:
      case UINT1:
      case UINT2:
      case UINT4:
      case UINT8:
      case TIME:
      case TIMESTAMP:
      case TIMESTAMPTZ:
      case DATE:
      case INTERVAL:
      case INTERVALDAY:
      case INTERVALYEAR:
        // nothing else matters.
        return true;
      case DECIMAL9:
      case DECIMAL18:
      case DECIMAL28DENSE:
      case DECIMAL28SPARSE:
      case DECIMAL38DENSE:
      case DECIMAL38SPARSE:
      case VARDECIMAL:
        return to.getScale() == from.getScale() && to.getPrecision() == from.getPrecision();

      case FIXED16CHAR:
      case FIXEDBINARY:
      case FIXEDCHAR:
        // width always matters
        this.errorCollector.addGeneralError(pos, "Casting fixed width types are not yet supported..");
        return false;

      case VAR16CHAR:
      case VARBINARY:
      case VARCHAR:
        // We could avoid redundant cast:
        // 1) when "to" length is no smaller than "from" length and "from" length is known (>0),
        // 2) or "to" length is unknown (0 means unknown length?).
        // Case 1 and case 2 mean that cast will do nothing.
        // In other cases, cast is required to trim the "from" according to "to" length.
        return (to.getPrecision() >= from.getPrecision() && from.getPrecision() > 0) || to.getPrecision() == 0;

      default:
        errorCollector.addGeneralError(pos, String.format("Casting rules are unknown for type %s.", from));
        return false;
      }
    }