R: Add content to the element of an Rd object or fragment at a...

append_to_Rd_list {Rdpack} | R Documentation

## Add content to the element of an Rd object or fragment at a given position

### Description

Add content to the element of an Rd object or fragment at a given position.

### Usage

    append_to_Rd_list(rdo, x, pos)

### Arguments

`rdo` | an Rd object
`x` | the content to append, an Rd object or a list of Rd objects.
`pos` | position at which to append `x`, typically an integer but may be anything accepted by the operator "[[".

### Details

The element of `rdo` at position `pos` is replaced by its concatenation with `x`. The result keeps the "Rd_tag" of `rdo[[pos]]`.

Argument `pos` may specify a position at any depth of the Rd object.

This function is relatively low level and is mainly for use by other functions.

### Value

the modified `rdo` object

### Author(s)

Georgi N. Boshnakov

### Examples

    rdoseq <- utils:::.getHelpFile(help("seq"))
    iusage <- which(tools:::RdTags(rdoseq) == "\\usage")

    ## append a new line after the last usage line
    rdoseq2 <- append_to_Rd_list(rdoseq, list(Rdo_newline()), iusage)

    ## Suppose that we wish to describe the function 'sequence' in the same Rd file.
    ## We append an usage statement for 'sequence()', without worrying about its
    ## actual signature.
    rdoseq2 <- append_to_Rd_list(rdoseq2, list(Rdo_Rcode("sequence()")), iusage)
    Rdo_show(rdoseq2)

    ## the two operations can be done in one step
    rdoseq3 <- append_to_Rd_list(rdoseq, list(Rdo_newline(), Rdo_Rcode("sequence()")), iusage)
    Rdo_show(rdoseq3)

    ## now run reprompt() to update rdoseq3, namely:
    ##    (1) it corrects the signature of 'sequence' in section \usage.
    ##    (2) reports new argument "nvec"
    ##    (3) inserts \item for the new argument(s) in section \arguments.
    reprompt(rdoseq3, filename=NA)

[Package Rdpack version 0.10-1 Index]