es: Expression substitution

In ore: An R Interface to the Onigmo Regular Expression Library

Expression substitution

Description

Evaluate R expressions and substitute their values into one or more strings.

Usage

es(text, round = NULL, signif = NULL, envir = parent.frame())

Arguments

text	A vector of strings to substitute into.
round	NULL or a single integer, giving the number of decimal digits for rounding numeric expressions. This argument takes priority over signif.
signif	NULL or a single integer, giving the number of significant decimal digits to use for numeric expressions. The round argument takes priority over this one, and will be used if not NULL.
envir	The environment to evaluate expressions in.

Details

Each part of the string surrounded by "#{}" is extracted, evaluated as R code in the specified environment, and then its value is substituted back into the string. The literal string "#{}" can be obtained by escaping the hash character, viz. "\\#{}". The block may contain multiple R expressions, separated by semicolons, but may not contain additional braces. Its value will be coerced to character mode, and if the result has multiple elements then the source string will be duplicated.

Value

The final strings, with expression values substituted into them.

See Also

ore_subst

Examples

es("pi is #{pi}")
es("pi is \\#{pi}")
es("The square-root of pi is approximately #{sqrt(pi)}", signif=4)
es("1/(1+x) for x=3 is #{x <- 3; 1/(1+x)}")

ore documentation built on Jan. 17, 2023, 1:10 a.m.