Add generic .AtNames() to support @ completion and export findMatches()

git-svn-id: https://svn.r-project.org/R/trunk@84159 00db46b3-68df-0310-9c12-caf00c1e9a41

src/library/utils/NAMESPACE

@@ -1,7 +1,7 @@
 # Refer to all C routines by their name prefixed by C_
 useDynLib(utils, .registration = TRUE, .fixes = "C_")
 
-export("?", .DollarNames, .S3methods, .romans, Rprof, Rprofmem,
+export("?", .AtNames, .DollarNames, .S3methods, .romans, Rprof, Rprofmem,
        RShowDoc, RSiteSearch, URLdecode, URLencode, View, adist,
        alarm, apropos, aregexec, argsAnywhere, asDateBuilt, askYesNo,
        assignInMyNamespace, assignInNamespace, as.roman, as.person,
@@ -17,7 +17,7 @@ export("?", .DollarNames, .S3methods, .romans, Rprof, Rprofmem,
        data.entry, dataentry, de, de.ncols, de.restore, de.setup,
        debugger, debugcall, demo, download.file, download.packages,
        dump.frames, edit, emacs, example, file_test, file.edit,
-       fileSnapshot, find, findCRANmirror, fix, fixInNamespace, findLineNum,
+       fileSnapshot, find, findCRANmirror, findMatches, fix, fixInNamespace, findLineNum,
        flush.console, formatOL, formatUL, getAnywhere, getCRANmirrors,
        getFromNamespace, getParseData, getParseText, getS3method,
        getSrcDirectory, getSrcFilename, getSrcLocation, getSrcref,
@@ -165,6 +165,7 @@ S3method("unique", "bibentry")
 S3method(.DollarNames, default)
 S3method(.DollarNames, list)
 S3method(.DollarNames, environment)
+S3method(.AtNames, default)
 
 export(Rtangle, RtangleSetup, RweaveLatex, RweaveLatexSetup, Stangle,
        Sweave, SweaveSyntConv, SweaveSyntaxLatex, SweaveSyntaxNoweb,

src/library/utils/R/completion.R

@@ -120,9 +120,10 @@ findFuzzyMatches <- function(pattern, values) {
 }
 
 
-findMatches <- function(pattern, values)
+findMatches <- function(pattern, values, fuzzy)
 {
-    if (.CompletionEnv$settings[["fuzzy"]])
+    if (missing(fuzzy)) fuzzy <- .CompletionEnv$settings[["fuzzy"]]
+    if (fuzzy)
         findFuzzyMatches(pattern, values)
     else
         findExactMatches(pattern, values)
@@ -160,6 +161,18 @@ fuzzyApropos <- function(what)
         findMatches(pattern, ls(x, all.names = TRUE))
 }
 
+## generic and default method to generate completion after @
+
+.AtNames <- function(x, pattern)
+    UseMethod(".AtNames")
+
+.AtNames.default <- function(x, pattern = "") {
+    if (isS4(x))
+        findMatches(pattern, methods::slotNames(x))
+    else
+        character()
+}
+
 ## if (is.environment(object))
 ## {
 ##     ls(object,
@@ -360,7 +373,6 @@ specialOpCompletionsHelper <- function(op, suffix, prefix)
                        suffix
                    else
                    {
-                       ## ## suffix must match names(object) (or ls(object) for environments)
                        .DollarNames(object, pattern = sprintf("^%s", makeRegexpSafe(suffix)))
                    }
                } else suffix
@@ -373,8 +385,7 @@ specialOpCompletionsHelper <- function(op, suffix, prefix)
                        suffix
                    else
                    {
-                       findMatches(sprintf("^%s", makeRegexpSafe(suffix)),
-                                   methods::slotNames(object))
+                       .AtNames(object, pattern = sprintf("^%s", makeRegexpSafe(suffix)))
                    }
                } else suffix
            },

src/library/utils/man/rcompgen.Rd

@@ -9,10 +9,13 @@
 \alias{rc.status}
 \alias{rc.getOption}
 \alias{rc.options}
+\alias{findMatches}
 \alias{.DollarNames}
 \alias{.DollarNames.default}
 \alias{.DollarNames.list}
 \alias{.DollarNames.environment}
+\alias{.AtNames}
+\alias{.AtNames.default}
 \alias{completion}
 
 \title{A Completion Generator for R}
@@ -36,10 +39,14 @@ rc.getOption(name)
 rc.options(\dots)
 
 .DollarNames(x, pattern)
+.AtNames(x, pattern)
 
 \S3method{.DollarNames}{default}(x, pattern = "")
 \S3method{.DollarNames}{list}(x, pattern = "")
 \S3method{.DollarNames}{environment}(x, pattern = "")
+\S3method{.AtNames}{default}(x, pattern = "")
+
+findMatches(pattern, values, fuzzy)
 
 }
 
@@ -95,7 +102,8 @@ rc.options(\dots)
   \item{fuzzy}{ Logical flag. Enables fuzzy matching, where close but
     non-exact matches (e.g., with different case) are considered if no
     exact matches are found.  This feature is experimental and the
-    details can change.  }
+    details can change. In \code{findMatches}, this argument defaults to
+    the current setting. }
 
   \item{quotes}{ Logical flag. Enables completion in \R code when inside
     quotes.  This normally leads to filename completion, but can be
@@ -123,6 +131,10 @@ rc.options(\dots)
   \item{pattern}{ A regular expression.  Only matching names are
     returned.
   }
+
+  \item{values}{ character string giving set of candidate values
+    in which matches are to be found.
+  }
 }
 
 \details{
@@ -151,9 +163,11 @@ rc.options(\dots)
       function call (implicit function calls involving the use of
       \code{[}, \code{$}, etc \emph{do not} inhibit evaluation).
 
-      Valid completions after the \code{$} extractor are determined by
-      the generic function \code{.DollarNames}.  Some basic methods are
-      provided, and more can be written for custom classes.
+      Valid completions after the \code{$} and \code{@} extractors are
+      determined by the generic functions \code{.DollarNames} and
+      \code{.AtNames} respectively. A few basic methods are provided,
+      and more can be written for custom classes. The \code{findMatches}
+      function can be useful for this purpose.
     }
 
     \item{\bold{Completion inside namespaces}:}{
@@ -244,6 +258,12 @@ rc.options(\dots)
     }
 
   }
+
+  \code{findMatches} is an utility function that is used internally to
+  determine matches. It can be used for writing methods for
+  \code{.DollarNames} or \code{.AtNames}, the main benefit being that it
+  will take the current \code{fuzzy} setting into account.
+
 }
 
 \value{
@@ -282,6 +302,9 @@ rc.options(\dots)
 
   \code{rc.getOption} and \code{rc.options} behave much like
   \code{\link{getOption}} and \code{\link{options}} respectively.
+
+  \code{findMatches} returns values that match the input pattern, taking
+  the \code{fuzzy} flag into account.
 }