wstring.R at c4b1d02 ⋅ HenrikBengtsson/R.rsp

setMethodS3("wstring", "default", function(..., sep="", envir=parent.frame()) {
  s <- paste(..., sep=sep)

  # Nothing to do?
  if (length(s) == 0L) return(s)
  if (length(s) > 1L) {
    Recall <- sys.function();  # base::Recall() does not work with *apply()
    return(sapply(s, FUN=Recall, envir=envir))
  }

  # Nothing to do?
  if (regexpr("{{", s, fixed=TRUE) == -1L) {
    return(s)
  }

  bfr <- NULL
  pattern <- "{{(.*?)}}"
  while ((pos <- regexpr(pattern, s, perl=TRUE)) != -1L) {
    # Parse
    len <- attr(pos, "match.length")
    head <- substring(s, first=1L, last=pos-1L)
    code <- substring(s, first=pos+2L, last=pos+len-3L)
    s <- substring(s, first=pos+len)

    # Evaluate
    expr <- base::parse(text=code)
    value <- eval(expr, envir=envir)
    value <- as.character(value)

    bfr <- c(bfr, head, value)
  }
  bfr <- c(bfr, s)
  bfr <- paste(bfr, collapse="")

  bfr
}, protected=TRUE) # wstring()

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1		setMethodS3("wstring", "default", function(..., sep="", envir=parent.frame()) {
2	1	s <- paste(..., sep=sep)
3
4		# Nothing to do?
5	0	if (length(s) == 0L) return(s)
6	1	if (length(s) > 1L) {
7	1	Recall <- sys.function(); # base::Recall() does not work with *apply()
8	1	return(sapply(s, FUN=Recall, envir=envir))
9		}
10
11		# Nothing to do?
12	1	if (regexpr("{{", s, fixed=TRUE) == -1L) {
13	1	return(s)
14		}
15
16	1	bfr <- NULL
17	1	pattern <- "{{(.*?)}}"
18	1	while ((pos <- regexpr(pattern, s, perl=TRUE)) != -1L) {
19		# Parse
20	1	len <- attr(pos, "match.length")
21	1	head <- substring(s, first=1L, last=pos-1L)
22	1	code <- substring(s, first=pos+2L, last=pos+len-3L)
23	1	s <- substring(s, first=pos+len)
24
25		# Evaluate
26	1	expr <- base::parse(text=code)
27	1	value <- eval(expr, envir=envir)
28	1	value <- as.character(value)
29
30	1	bfr <- c(bfr, head, value)
31		}
32	1	bfr <- c(bfr, s)
33	1	bfr <- paste(bfr, collapse="")
34
35	1	bfr
36		}, protected=TRUE) # wstring()