REBOL Document

Change - Function Summary


Changes a value in a series and returns the series after the change.


change series value


series - Series at point to change (must be: series port)

value - The new value (must be: any-type)


/part - Limits the amount to change to a given length or position.

range - The range argument. (must be: number series port pair)

/only - Changes a series as a series.

/dup - Duplicates the change a specified number of times.

count - The count argument. (must be: number pair)


If the second argument is a simple value, it will replace the value at the current position in the first series. If the second argument is a series compatible with the first (block or string-based datatype), all of its values will replace those of the first argument or series.

The /PART refinement changes a specified number of elements within the target series.

For the convenience of cascading multiple changes the CHANGE function returns the series position just past the change.

    probe head change "bog" "d"

    probe head change [123 "test"] "the"
    ["the" "test"]

    probe head change/dup "abc" "->" 5

    probe head change/part "abcde" "1234" 2

    probe head change [1 4 5] [1 2 3]
    [1 2 3]

    title: copy "how it REBOL"
    change title "N"
    probe title
    "Now it REBOL"

    change find title "t" "s"
    probe title
    "Now is REBOL"

    blk: copy ["now" 12:34 "REBOL"]
    change next blk "is"
    probe blk
    ["now" "is" "REBOL"]

    probe head change/only [1 4 5] [1 2 3]
    [[1 2 3] 4 5]

    probe head change/only [1 4 5] [[1 2 3]]
    [[[1 2 3]] 4 5]

    string: copy "crush those grapes"
    change/part string "eat" find/tail string "crush"
    probe string
    "eat those grapes"


append - Appends a value to the tail of a series and returns the series head.
clear - Removes all values from the current index to the tail. Returns at tail.
insert - Inserts a value into a series and returns the series after the insert.
remove - Removes value(s) from a series and returns after the remove.
sort - Sorts a series.

User Comments:

-From: 30-Dec-2000/13:02:33-8:00:

Change is also handy inside 'parse rule actions. For example:

    Mark: "---" MarkEnd: (
        MarkEnd: change/part Mark "&emdash;" MarkEnd
    ) :MarkEnd

changes the input string and jumps over the replaced text.

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