Character string with advanced substitutions
Package: R.utils
Class GString
character~~|~~+--GString
Directly known subclasses:
public static class GString
extends character
GString(..., sep="")
Methods:
as.character |
Gets the processed character string. | |
evaluate |
Parses and evaluates a GString. | |
gcat |
- | |
getBuiltinDate |
Gets the current date. | |
getBuiltinDatetime |
Gets the current date and time. | |
getBuiltinHostname |
Gets the hostname of the system running R. | |
getBuiltinOs |
Gets the operating system of the running machine. | |
getBuiltinPid |
Gets the process id of the current R session. | |
getBuiltinRhome |
Gets the path where R is installed. | |
getBuiltinRversion |
Gets the current R version. | |
getBuiltinTime |
Gets the current time. | |
getBuiltinUsername |
Gets the username of the user running R. | |
getRaw |
Gets the unprocessed GString. | |
getVariableValue |
Gets a variable value given a name and attributes. | |
gstring |
- | |
parse |
Parses a GString. | |
print |
Prints the processed GString. | |
Methods inherited from character:
Ops,nonStructure,vector-method, Ops,structure,vector-method, Ops,vector,nonStructure-method, Ops,vector,structure-method, all.equal, as.Date, as.POSIXlt, as.data.frame, as.raster, coerce,ANY,character-method, coerce,character,SuperClassMethod-method, coerce,character,signature-method, coerce<-,ObjectsWithPackage,character-method, coerce<-,signature,character-method, downloadFile, formula, getDLLRegisteredRoutines, isOpen, toAsciiRegExprPattern, toFileListTree, uses
Henrik Bengtsson
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# First example
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who <- "world"
# Compare this...
cat(as.character(GString("Hello ${who}\n")))
# ...to this.
cat(GString("Hello ${who}\n"))
# Escaping
cat(as.character(GString("Hello \\${who}\n")))
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# Looping over vectors
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x <- 1:5
y <- c("hello", "world")
cat(as.character(GString("(x,y)=(${x},${y})")), sep=", ")
cat("\n")
cat(as.character(GString("(x,y)=(${x},$[capitalize]{y})")), sep=", ")
cat("\n")
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# Predefined ("builtin") variables
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cat(as.character(GString("Hello ${username} on host ${hostname} running ",
"R v${rversion} in process #${pid} on ${os}. R is installed in ${rhome}.")))
# Other built-in variables/functions...
cat(as.character(GString("Current date: ${date}\n")))
cat(as.character(GString("Current date: $[format='%d/%m/%y']{date}\n")))
cat(as.character(GString("Current time: ${time}\n")))
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# Evaluating inline R code
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cat(as.character(GString("Simple calculation: 1+1=${`1+1`}\n")))
cat(as.character(GString("Alternative current date: ${`date()`}\n")))
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# Function values
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# Call function rnorm with arguments n=1, i.e. rnorm(n=1)
cat(as.character(GString("Random normal number: $[n=1]{rnorm}\n")))
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# Global search-replace feature
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# Replace all '-' with '.'
cat(as.character(GString("Current date: ${date/-/.}\n")))
# Another example
cat(as.character(GString("Escaped string: 12*12=${`12*12`/1/}\n")))
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# Defining new "builtin" function values
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# Define your own builtin variables (functions)
setMethodS3("getBuiltinAletter", "GString", function(object, ...) {
base::letters[runif(1, min=1, max=length(base::letters))]
})
cat(as.character(GString("A letter: ${aletter}\n")))
cat(as.character(GString("Another letter: ${aletter}\n")))
# Another example
setMethodS3("getBuiltinGstring", "GString", function(object, ...) {
# Return another GString.
GString("${date} ${time}")
})
cat(as.character(GString("Advanced example: ${gstring}\n")))
# Advanced example
setMethodS3("getBuiltinRunif", "GString", function(object, n=1, min=0, max=1, ...) {
formatC(runif(n=n, min=min, max=max), ...)
})
cat(as.character(GString("A random number: ${runif}\n")))
n <- 5
cat(as.character(GString("${n} random numbers: ")))
cat(as.character(GString("$[n=n, format='f']{runif}")))
cat("\n")
# Advanced options.
# Options are parsed as if they are elements in a list, e.g.
# list(n=runif(n=1,min=1,max=5), format='f')
cat(as.character(GString("$Random number of numbers: ")))
cat(as.character(GString("$[n=runif(n=1,min=1,max=5), format='f']{runif}")))
cat("\n")Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.