Package groovy.lang

Class IntRange

  • All Implemented Interfaces:
    Range<Integer>, Iterable<Integer>, Collection<Integer>, List<Integer>
    public class IntRange
extends AbstractList<Integer>
implements Range<Integer>
    Represents a list of Integer objects starting at a specified from value up (or down) to and potentially including a given to value.

    Instances of this class may be either inclusive aware or non-inclusive aware. See the relevant constructors for creating each type. Inclusive aware IntRange instances are suitable for use with Groovy's range indexing - in particular if the from or to values might be negative. This normally happens underneath the covers but is worth keeping in mind if creating these ranges yourself explicitly.

    Note: the design of this class might seem a little strange at first. It contains a Boolean field, inclusive, which can be true, false or null. This design is for backwards compatibility reasons. Groovy uses this class under the covers to represent range indexing, e.g. someList[x..y] and someString[x..<y]. In early versions of Groovy the ranges in these expressions were represented under the covers by the new IntRange(x, y) and new IntRange(x, y-1). This turns out to be a lossy abstraction when x and/or y are negative values. Now the latter case is represented by new IntRange(false, x, y).

    Note: This class is a copy of ObjectRange optimized for int. If you make any changes to this class, you might consider making parallel changes to ObjectRange.

    • Constructor Detail

      • IntRange

        public IntRange​(int from,
                int to)
        Creates a new non-inclusive aware IntRange. If from is greater than to, a reverse range is created with from and to swapped.
        Parameters:
        from - the first number in the range.
        to - the last number in the range.
        Throws:
        IllegalArgumentException - if the range would contain more than Integer.MAX_VALUE values.

      • IntRange

        protected IntRange​(int from,
                   int to,
                   boolean reverse)
        Creates a new non-inclusive aware IntRange.
        Parameters:
        from - the first value in the range.
        to - the last value in the range.
        reverse - true if the range should count from to to from.
        Throws:
        IllegalArgumentException - if from is greater than to.

      • IntRange

        public IntRange​(boolean inclusive,
                int from,
                int to)
        Creates a new inclusive aware IntRange.
        Parameters:
        from - the first value in the range.
        to - the last value in the range.
        inclusive - true if the to value is included in the range.

    • Method Detail

      • by

        public <T extends Number & Comparable> NumberRange by​(T stepSize)
        Creates a new NumberRange with the same from and to as this IntRange but with a step size of stepSize.
        Parameters:
        stepSize - the desired step size
        Returns:
        a new NumberRange
        Since:
        2.5.0

      • subListBorders

        public RangeInfo subListBorders​(int size)
        A method for determining from and to information when using this IntRange to index an aggregate object of the specified size. Normally only used internally within Groovy but useful if adding range indexing support for your own aggregates.
        Parameters:
        size - the size of the aggregate being indexed
        Returns:
        the calculated range information (with 1 added to the to value, ready for providing to subList

      • equals

        public boolean equals​(IntRange that)
        Compares an IntRange to another IntRange.
        Parameters:
        that - the object to compare for equality
        Returns:
        true if the ranges are equal

      • getFrom

        public Integer getFrom()
        Description copied from interface: Range
        The lower value in the range.
        Specified by:
        getFrom in interface Range<Integer>
        Returns:
        the lower value in the range.

      • getTo

        public Integer getTo()
        Description copied from interface: Range
        The upper value in the range.
        Specified by:
        getTo in interface Range<Integer>
        Returns:
        the upper value in the range

      • getInclusive

        public Boolean getInclusive()
        Returns the inclusive flag. Null for non-inclusive aware ranges or non-null for inclusive aware ranges.

      • getFromInt

        public int getFromInt()
        Gets the 'from' value as a primitive integer.
        Returns:
        the 'from' value as a primitive integer.

      • getToInt

        public int getToInt()
        Gets the 'to' value as a primitive integer.
        Returns:
        the 'to' value as a primitive integer.

      • isReverse

        public boolean isReverse()
        Description copied from interface: Range
        Indicates whether this is a reverse range which iterates backwards starting from the to value and ending on the from value
        Specified by:
        isReverse in interface Range<Integer>
        Returns:
        true if this is a reverse range

      • containsWithinBounds

        public boolean containsWithinBounds​(Object o)
        Description copied from interface: Range
        Indicates whether an object is greater than or equal to the from value for the range and less than or equal to the to value.

        This may be true even for values not contained in the range. Example: from = 1.5, to = 3, next() increments by 1 containsWithinBounds(2) == true contains(2) == false

        Specified by:
        containsWithinBounds in interface Range<Integer>
        Parameters:
        o - the object to check against the boundaries of the range
        Returns:
        true if the object is between the from and to values

      • inspect

        public String inspect()
        Specified by:
        inspect in interface Range<Integer>
        Returns:
        the verbose String representation of this Range as would be typed into a console to create the Range instance

      • step

        public void step​(int step,
                 Closure closure)
        Description copied from interface: Range
        Steps through the range, calling a closure for each item.
        Specified by:
        step in interface Range<Integer>
        Parameters:
        step - the amount by which to step. If negative, steps through the range backwards.
        closure - the Closure to call

      • step

        public List<Integer> step​(int step)
        Description copied from interface: Range
        Forms a list by stepping through the range by the indicated interval.
        Specified by:
        step in interface Range<Integer>
        Parameters:
        step - the amount by which to step. If negative, steps through the range backwards.
        Returns:
        the list formed by stepping through the range by the indicated interval.