Christophe Weblog Wiki Code Publications Music
fix null implementation of operator-arglist
[swankr.git] / swank.R
diff --git a/swank.R b/swank.R
index b7c4df3..99012ec 100644 (file)
--- a/swank.R
+++ b/swank.R
@@ -1,15 +1,42 @@
+### This program is free software; you can redistribute it and/or
+### modify it under the terms of the GNU General Public Licence as
+### published by the Free Software Foundation; either version 2 of the
+### Licence, or (at your option) any later version.
+###
+### This program is distributed in the hope that it will be useful,
+### but WITHOUT ANY WARRANTY; without even the implied warranty of
+### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+### GNU General Public Licence for more details.
+###
+### A copy of version 2 of the GNU General Public Licence is available
+### at <http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt>; the
+### latest version of the GNU General Public Licence is available at
+### <http://www.gnu.org/licenses/gpl.txt>.
+
+### KLUDGE: this assumes that we're being sourced with chdir=TRUE.
+### (If not, `swank:swank-require` will work under the circumstances
+### that it used to work anyway -- i.e. the working directory is the
+### swankr directory)
+swankrPath <- getwd() 
+
 swank <- function(port=4005) {
   acceptConnections(port, FALSE)
 }
 
 startSwank <- function(portFile) {
-  acceptConnections(FALSE, portFile)
+  acceptConnections(4005, portFile)
 }
 
 acceptConnections <- function(port, portFile) {
+  if(portFile != FALSE) {
+    f <- file(portFile, open="w+")
+    cat(port, file=f)
+    close(f)
+  }
+  ## FIXME: maybe we should support dontClose here?
   s <- socketConnection(host="localhost", server=TRUE, port=port, open="r+b")
   on.exit(close(s))
-  serve(s)
+  tryCatch(serve(s), endOfFile=function(c) NULL)
 }
 
 serve <- function(io) {
@@ -17,82 +44,100 @@ serve <- function(io) {
 }
 
 mainLoop <- function(io) {
+  slimeConnection <- new.env()
+  slimeConnection$io <- io
   while(TRUE) {
-    tryCatch(dispatch(io, readPacket(io)),
-             swankTopLevel=function(c) NULL)
+    withRestarts(tryCatch(dispatch(slimeConnection, readPacket(io)),
+                          swankTopLevel=function(c) NULL),
+                 abort="return to SLIME's toplevel")
   }
 }
 
-dispatch <- function(io, event, sldbState=NULL) {
-  str(event)
+dispatch <- function(slimeConnection, event, sldbState=NULL) {
   kind <- event[[1]]
   if(kind == quote(`:emacs-rex`)) {
-    do.call("emacsRex", c(list(io), list(sldbState), event[-1]))
+    do.call("emacsRex", c(list(slimeConnection), list(sldbState), event[-1]))
   }
 }
 
-sendToEmacs <- function(io, obj) {
-  str(obj)
+sendToEmacs <- function(slimeConnection, obj) {
+  io <- slimeConnection$io
   payload <- writeSexpToString(obj)
-  writeChar(sprintf("%06x", nchar(payload)), io, eos=NULL)
+  writeChar(sprintf("%06x", nchar(payload, type="bytes")), io, eos=NULL)
   writeChar(payload, io, eos=NULL)
   flush(io)
-  cat(sprintf("%06x", nchar(payload)), payload, sep="")
 }
 
-emacsRex <- function(io, sldbState, form, pkg, thread, id, level=0) {
+callify <- function(form) {
+  ## we implement here the conversion from Lisp S-expression (or list)
+  ## expressions of code into our own, swankr, calling convention,
+  ## with slimeConnection and sldbState as first and second arguments.
+  ## as.call() gets us part of the way, but we need to walk the list
+  ## recursively to mimic CL:EVAL; we need to avoid converting R
+  ## special operators which we are punning (only `quote`, for now)
+  ## into this calling convention.
+  if(is.list(form)) {
+    if(form[[1]] == quote(quote)) {
+      as.call(form)
+    } else {
+      as.call(c(list(form[[1]], quote(slimeConnection), quote(sldbState)), lapply(form[-1], callify)))
+    }
+  } else {
+    form
+  }
+}
+
+emacsRex <- function(slimeConnection, sldbState, form, pkg, thread, id, level=0) {
   ok <- FALSE
   value <- NULL
+  conn <- textConnection(NULL, open="w")
+  condition <- NULL
   tryCatch({
     withCallingHandlers({
-      value <- do.call(eval(form[[1]]), c(list(io), list(sldbState), form[-1]))
+      call <- callify(form)
+      capture.output(value <- eval(call), file=conn)
+      string <- paste(textConnectionValue(conn), sep="", collapse="\n")
+      if(nchar(string) > 0) {
+        sendToEmacs(slimeConnection, list(quote(`:write-string`), string))
+        sendToEmacs(slimeConnection, list(quote(`:write-string`), "\n"))
+      }
+      close(conn)
       ok <- TRUE
     }, error=function(c) {
+      condition <<- c
+      string <- paste(textConnectionValue(conn), sep="", collapse="\n")
+      if(nchar(string) > 0) {
+        sendToEmacs(slimeConnection, list(quote(`:write-string`), string))
+        sendToEmacs(slimeConnection, list(quote(`:write-string`), "\n"))
+      }
+      close(conn)
       newSldbState <- makeSldbState(c, if(is.null(sldbState)) 0 else sldbState$level+1, id)
-      sldbLoop(io, newSldbState, id) })},
-    finally=sendToEmacs(io, list(quote(`:return`), if(ok) list(quote(`:ok`), value) else list(quote(`:abort`)), id)))
+      withRestarts(sldbLoop(slimeConnection, newSldbState, id), abort=paste("return to sldb level", newSldbState$level)) })},
+    finally=sendToEmacs(slimeConnection, list(quote(`:return`), if(ok) list(quote(`:ok`), value) else list(quote(`:abort`), as.character(condition)), id)))
 }
 
 makeSldbState <- function(condition, level, id) {
   calls <- rev(sys.calls())[-1]
   frames <- rev(sys.frames())[-1]
-  ret <- list(condition=condition, level=level, id=id, calls=calls, frames=frames)
+  restarts <- rev(computeRestarts(condition))[-1]
+  ret <- list(condition=condition, level=level, id=id, restarts=restarts, calls=calls, frames=frames)
   class(ret) <- c("sldbState", class(ret))
   ret
 }
 
-sldbLoop <- function(io, sldbState, id) {
-  sendToEmacs(io, c(list(quote(`:debug`), id, sldbState$level), debuggerInfoForEmacs(sldbState)))
-  sendToEmacs(io, list(quote(`:debug-activate`), id, sldbState$level, FALSE))
-  while(TRUE) {
-    dispatch(io, readPacket(io), sldbState)
-  }
-}
-
-debuggerInfoForEmacs <- function(sldbState, from=0, to=NULL) {
-  backtraceForEmacs <- function() {
-    calls <- sldbState$calls
-    if(is.null(to)) to <- length(calls)
-    from <- from+1
-    calls <- lapply(calls[from:to], { frameNumber <- from-1;
-                             function (x) { ret <- list(frameNumber, paste(format(x), sep="", collapse=" ")); frameNumber <<- 1+frameNumber; ret }})
-  }
-  computeRestartsForEmacs <- function () {
-    lapply(computeRestarts(sldbState$condition),
-           function(x) {
-             ## this is all a little bit internalsy
-             restartName <- x[[1]][[1]]
-             description <- restartDescription(x)
-             list(restartName, if(is.null(description)) restartName else description)
-           })
-  }
-  list(list(as.character(sldbState$condition), sprintf("  [%s]", class(sldbState$condition)[[1]]), FALSE),
-       computeRestartsForEmacs(),
-       backtraceForEmacs(),
-       list(sldbState$id))
+sldbLoop <- function(slimeConnection, sldbState, id) {
+  tryCatch({
+    io <- slimeConnection$io
+    sendToEmacs(slimeConnection, c(list(quote(`:debug`), id, sldbState$level), `swank:debugger-info-for-emacs`(slimeConnection, sldbState)))
+    sendToEmacs(slimeConnection, list(quote(`:debug-activate`), id, sldbState$level, FALSE))
+    while(TRUE) {
+      dispatch(slimeConnection, readPacket(io), sldbState)
+    }
+  }, finally=sendToEmacs(slimeConnection, c(list(quote(`:debug-return`), id, sldbState$level, FALSE))))
 }
 
 readPacket <- function(io) {
+  socketSelect(list(io))
   header <- readChunk(io, 6)
   len <- strtoi(header, base=16)
   payload <- readChunk(io, len)
@@ -101,6 +146,11 @@ readPacket <- function(io) {
 
 readChunk <- function(io, len) {
   buffer <- readChar(io, len)
+  if(length(buffer) == 0) {
+    condition <- simpleCondition("End of file on io")
+    class(condition) <- c("endOfFile", class(condition))
+    signalCondition(condition)
+  }
   if(nchar(buffer) != len) {
     stop("short read in readChunk")
   }
@@ -177,7 +227,14 @@ readSexpFromString <- function(string) {
     } else if(grepl("^[0-9]+\\.[0-9]+$", token)) {
       as.double(token)
     } else {
-      as.name(token)
+      name <- as.name(token)
+      if(name == quote(t)) {
+        TRUE
+      } else if(name == quote(nil)) {
+        FALSE
+      } else {
+        name
+      }
     }
   }
   readToken <- function() {
@@ -224,66 +281,522 @@ writeSexpToString <- function(obj) {
   writeSexpToStringLoop(obj)
 }
 
+prin1ToString <- function(val) {
+  paste(deparse(val, backtick=TRUE, control=c("delayPromises", "keepNA")),
+        sep="", collapse="\n")
+}
+
 printToString <- function(val) {
-  f <- fifo("")
-  sink(f)
-  print(val)
-  sink()
-  readLines(f)
+  paste(capture.output(print(val)), sep="", collapse="\n")
 }
 
-`swank:connection-info` <- function (io, sldbState) {
+`swank:connection-info` <- function (slimeConnection, sldbState) {
   list(quote(`:pid`), Sys.getpid(),
        quote(`:package`), list(quote(`:name`), "R", quote(`:prompt`), "R> "),
+       quote(`:version`), "2012-04-23",
+       quote(`:encoding`), list(quote(`:coding-systems`), list("utf-8-unix")),
        quote(`:lisp-implementation`), list(quote(`:type`), "R",
                                            quote(`:name`), "R",
                                            quote(`:version`), paste(R.version$major, R.version$minor, sep=".")))
 }
 
-`swank:swank-require` <- function (io, sldbState, contribs) {
+`swank:swank-require` <- function (slimeConnection, sldbState, contribs) {
+  for(contrib in contribs) {
+    filename <- sprintf("%s/%s.R", swankrPath, as.character(contrib))
+    if(file.exists(filename)) {
+      source(filename)
+    }
+  }
   list()
 }
 
-`swank:create-repl` <- function(io, sldbState, env, ...) {
+`swank:create-repl` <- function(slimeConnection, sldbState, env, ...) {
   list("R", "R")
 }
 
-`swank:listener-eval` <- function(io, sldbState, string) {
-  val <- eval(parse(text=string), envir = globalenv())
-  string <- printToString(val)
-  list(quote(`:values`), paste(string, collapse="\n"))
+makeReplResult <- function(value) {
+  string <- printToString(value)
+  list(quote(`:write-string`), string,
+       quote(`:repl-result`))
+}
+
+makeReplResultFunction <- makeReplResult
+
+sendReplResult <- function(slimeConnection, value) {
+  result <- makeReplResultFunction(value)
+  sendToEmacs(slimeConnection, result)
+}
+
+sendReplResultFunction <- sendReplResult
+
+`swank:listener-eval` <- function(slimeConnection, sldbState, string) {
+  ## O how ugly
+  string <- gsub("#\\.\\(swank:lookup-presented-object-or-lose([^)]*)\\)", ".(`swank:lookup-presented-object-or-lose`(slimeConnection, sldbState,\\1))", string)
+  for(expr in parse(text=string)) {
+    expr <- expr
+    ## O maybe this is even uglier
+    lookedup <- do.call("bquote", list(expr))
+    tmp <- withVisible(eval(lookedup, envir = globalenv()))
+    if(tmp$visible) {
+      sendReplResultFunction(slimeConnection, tmp$value)
+    }
+  }
+  list()
 }
 
-`swank:autodoc` <- function(io, sldbState, rawForm, ...) {
-  "No Arglist Information"
+`swank:autodoc` <- function(slimeConnection, sldbState, rawForm, ...) {
+  list("No Arglist Information", TRUE)
+}
+
+`swank:operator-arglist` <- function(slimeConnection, sldbState, op, package) {
+  if(!exists(op, envir = globalenv())) {
+    return(list())
+  }
+  funoid <- get(op, envir = globalenv())
+  if(is.function(funoid)) {
+    args <- formals(funoid)
+    paste(sprintf("%s=%s", names(args), args), collapse=", ")
+  } else {
+    list()
+  }
 }
 
-`swank:throw-to-toplevel` <- function(io, sldbState) {
+`swank:throw-to-toplevel` <- function(slimeConnection, sldbState) {
   condition <- simpleCondition("Throw to toplevel")
   class(condition) <- c("swankTopLevel", class(condition))
   signalCondition(condition)
 }
 
-`swank:debugger-info-for-emacs` <- function(io, sldbState, from, to) {
-  debuggerInfoForEmacs(sldbState, from=from, to=to)
+`swank:backtrace` <- function(slimeConnection, sldbState, from=0, to=NULL) {
+  calls <- sldbState$calls
+  if(is.null(to)) to <- length(calls)
+  from <- from+1
+  calls <- lapply(calls[from:to],
+                  { frameNumber <- from-1;
+                    function (x) {
+                      ret <- list(frameNumber, paste(format(x), sep="", collapse=" "))
+                      frameNumber <<- 1+frameNumber
+                      ret
+                    }
+                  })
+}
+
+computeRestartsForEmacs <- function (sldbState) {
+  lapply(sldbState$restarts,
+         function(x) {
+           ## this is all a little bit internalsy
+           restartName <- x[[1]][[1]]
+           description <- restartDescription(x)
+           list(restartName, if(is.null(description)) restartName else description)
+         })
 }
 
-`swank:invoke-nth-restart-for-emacs` <- function(io, sldbState, level, n) {
+`swank:debugger-info-for-emacs` <- function(slimeConnection, sldbState, from=0, to=NULL) {
+  list(list(as.character(sldbState$condition), sprintf("  [%s]", class(sldbState$condition)[[1]]), FALSE),
+       computeRestartsForEmacs(sldbState),
+       `swank:backtrace`(slimeConnection, sldbState, from, to),
+       list(sldbState$id))
+}
+
+`swank:invoke-nth-restart-for-emacs` <- function(slimeConnection, sldbState, level, n) {
   if(sldbState$level == level) {
-    invokeRestart(computeRestarts()[[n+1]])
+    invokeRestart(sldbState$restarts[[n+1]])
   }
 }
 
-`swank:buffer-first-change` <- function(io, sldbState, filename) {
+`swank:frame-source-location` <- function(slimeConnection, sldbState, n) {
+  call <- sldbState$calls[[n+1]]
+  srcref <- attr(call, "srcref")
+  srcfile <- attr(srcref, "srcfile")
+  if(is.null(srcfile)) {
+    list(quote(`:error`), "no srcfile")
+  } else {
+    filename <- get("filename", srcfile)
+    ## KLUDGE: what this means is "is the srcfile filename
+    ## absolute?"
+    if(substr(filename, 1, 1) == "/") {
+      file <- filename
+    } else {
+      file <- sprintf("%s/%s", srcfile$wd, filename)
+    }
+    list(quote(`:location`),
+         list(quote(`:file`), file),
+         list(quote(`:line`), srcref[[1]], srcref[[2]]-1),
+         FALSE)
+  }
+}
+
+`swank:buffer-first-change` <- function(slimeConnection, sldbState, filename) {
   FALSE
 }
 
-`swank:frame-locals-and-catch-tags` <- function(io, sldbState, index) {
-  str(sldbState$frames)
+`swank:eval-string-in-frame` <- function(slimeConnection, sldbState, string, index) {
+  frame <- sldbState$frames[[1+index]]
+  withRetryRestart("retry SLIME interactive evaluation request",
+                   value <- eval(parse(text=string), envir=frame))
+  printToString(value)
+}
+
+`swank:frame-locals-and-catch-tags` <- function(slimeConnection, sldbState, index) {
   frame <- sldbState$frames[[1+index]]
   objs <- ls(envir=frame)
+  if(identical(frame, globalenv())) {
+    objs <- c()
+  }
   list(lapply(objs, function(name) { list(quote(`:name`), name,
                                           quote(`:id`), 0,
-                                          quote(`:value`), paste(printToString(eval(parse(text=name), envir=frame)), sep="", collapse="\n")) }),
+                                          quote(`:value`),
+                                          tryCatch({
+                                            printToString(eval(parse(text=name), envir=frame))
+                                          }, error=function(c) {
+                                            sprintf("error printing object")
+                                          }))}),
        list())
 }
+
+`swank:simple-completions` <- function(slimeConnection, sldbState, prefix, package) {
+  symbolFieldsCompletion <- function(object, rest) {
+    ## FIXME: this is hacky, ignoring several syntax issues (use of
+    ## and/or necessity for backquoting identifiers: e.g. fields
+    ## containing hyphens)
+    if((dollar <- regexpr("$", rest, fixed=TRUE)) == -1) {
+      matches <- grep(sprintf("^%s", literal2rx(rest)), names(object), value=TRUE)
+      matches <- sprintf("%s$%s", gsub("\\$[^$]*$", "", prefix), matches)
+      returnMatches(matches)
+    } else {
+      if(exists(substr(rest, 1, dollar-1), object)) {
+        symbolFieldsCompletion(get(substr(rest, 1, dollar-1), object), substr(rest, dollar+1, nchar(rest)))
+      } else {
+        returnMatches(character(0))
+      }
+    }
+  }
+  returnMatches <- function(matches) {
+    nmatches <- length(matches)
+    if(nmatches == 0) {
+      list(list(), "")
+    } else {
+      longest <- matches[order(nchar(matches))][1]
+      while(length(grep(sprintf("^%s", literal2rx(longest)), matches)) < nmatches) {
+        longest <- substr(longest, 1, nchar(longest)-1)
+      }
+      list(as.list(matches), longest)
+    }
+  }
+  literal2rx <- function(string) {
+    ## list of ERE metacharacters from ?regexp
+    gsub("([.\\|()[{^$*+?])", "\\\\\\1", string)
+  }
+  matches <- apropos(sprintf("^%s", literal2rx(prefix)), ignore.case=FALSE)
+  nmatches <- length(matches)
+  if((nmatches == 0) && ((dollar <- regexpr("$", prefix, fixed=TRUE)) > -1)) {
+    symbolFieldsCompletion(globalenv(), prefix)
+  } else {
+    returnMatches(matches)
+  }
+}
+
+`swank:compile-string-for-emacs` <- function(slimeConnection, sldbState, string, buffer, position, filename, policy) {
+  lineOffset <- charOffset <- colOffset <- NULL
+  for(pos in position) {
+    switch(as.character(pos[[1]]),
+           `:position` = {charOffset <- pos[[2]]},
+           `:line` = {lineOffset <- pos[[2]]; colOffset <- pos[[3]]},
+           warning("unknown content in pos", pos))
+  }
+  frob <- function(refs) {
+    lapply(refs,
+           function(x)
+           srcref(attr(x,"srcfile"),
+                  c(x[1]+lineOffset-1, ifelse(x[1]==1, x[2]+colOffset-1, x[2]),
+                    x[3]+lineOffset-1, ifelse(x[3]==1, x[4]+colOffset-1, x[4]),
+                    ifelse(x[1]==1, x[5]+colOffset-1, x[5]),
+                    ifelse(x[3]==1, x[6]+colOffset-1, x[6]))))
+  }
+  transformSrcrefs <- function(s) {
+    srcrefs <- attr(s, "srcref")
+    attribs <- attributes(s)
+    new <- 
+      switch(mode(s),
+             "call"=as.call(lapply(s, transformSrcrefs)),
+             "expression"=as.expression(lapply(s, transformSrcrefs)),
+             s)
+    attributes(new) <- attribs
+    if(!is.null(attr(s, "srcref"))) {
+      attr(new, "srcref") <- frob(srcrefs)
+    }
+    new
+  }
+  withRestarts({
+    times <- system.time({
+      exprs <- parse(text=string, srcfile=srcfile(filename))
+      eval(transformSrcrefs(exprs), envir = globalenv()) })},
+               abort="abort compilation")
+  list(quote(`:compilation-result`), list(), TRUE, times[3], FALSE, FALSE)
+}
+
+withRetryRestart <- function(description, expr) {
+  call <- substitute(expr)
+  retry <- TRUE
+  while(retry) {
+    retry <- FALSE
+    withRestarts(eval.parent(call),
+                 retry=list(description=description,
+                   handler=function() retry <<- TRUE))
+  }
+}
+
+`swank:interactive-eval` <-  function(slimeConnection, sldbState, string) {
+  withRetryRestart("retry SLIME interactive evaluation request",
+                   tmp <- withVisible(eval(parse(text=string), envir=globalenv())))
+  if(tmp$visible) {
+    prin1ToString(tmp$value)
+  } else {
+    "# invisible value"
+  }
+}
+
+`swank:eval-and-grab-output` <- function(slimeConnection, sldbState, string) {
+  withRetryRestart("retry SLIME interactive evaluation request",
+                   { output <-
+                       capture.output(tmp <- withVisible(eval(parse(text=string),
+                                                              envir=globalenv()))) })
+  output <- paste(output, sep="", collapse="\n")
+  if(tmp$visible) {
+    list(output, prin1ToString(tmp$value))
+  } else {
+    list(output, "# invisible value")
+  }
+}
+
+`swank:interactive-eval-region` <- function(slimeConnection, sldbState, string) {
+  withRetryRestart("retry SLIME interactive evaluation request",
+                   tmp <- withVisible(eval(parse(text=string), envir=globalenv())))
+  if(tmp$visible) {
+    prin1ToString(tmp$value)
+  } else {
+    "# invisible value"
+  }
+}
+
+`swank:find-definitions-for-emacs` <- function(slimeConnection, sldbState, string) {
+  if(exists(string, envir = globalenv())) {
+    thing <- get(string, envir = globalenv())
+    if(inherits(thing, "function")) {
+      body <- body(thing)
+      srcref <- attr(body, "srcref")
+      srcfile <- attr(body, "srcfile")
+      if(is.null(srcfile)) {
+        list()
+      } else {
+        filename <- get("filename", srcfile)
+        ## KLUDGE: what this means is "is the srcfile filename
+        ## absolute?"
+        if(substr(filename, 1, 1) == "/") {
+          file <- filename
+        } else {
+          file <- sprintf("%s/%s", srcfile$wd, filename)
+        }
+        list(list(sprintf("function %s", string),
+                  list(quote(`:location`),
+                       list(quote(`:file`), file),
+                       list(quote(`:line`), srcref[[2]][[1]], srcref[[2]][[2]]-1),
+                       list())))
+      }
+    } else {
+      list()
+    }
+  } else {
+    list()
+  }
+}
+
+`swank:value-for-editing` <- function(slimeConnection, sldbState, string) {
+  paste(deparse(eval(parse(text=string), envir = globalenv()), control="all"),
+        collapse="\n", sep="")
+}
+
+`swank:commit-edited-value` <- function(slimeConnection, sldbState, string, value) {
+  eval(parse(text=sprintf("%s <- %s", string, value)), envir = globalenv())
+  TRUE
+}
+
+resetInspector <- function(slimeConnection) {
+  assign("istate", list(), envir=slimeConnection)
+  assign("inspectorHistory", NULL, envir=slimeConnection)
+}
+
+`swank:init-inspector` <- function(slimeConnection, sldbState, string) {
+  withRetryRestart("retry SLIME inspection request",
+                   { resetInspector(slimeConnection)
+                     value <- inspectObject(slimeConnection, eval(parse(text=string), envir=globalenv()))
+                   })
+  value
+}
+
+inspectObject <- function(slimeConnection, object) {
+  vectorify <- function(x) {
+    if(is.vector(x)) {
+      x
+    } else {
+      list(x)
+    }
+  }
+  previous <- slimeConnection$istate
+  slimeConnection$istate <- new.env()
+  slimeConnection$istate$object <- object
+  slimeConnection$istate$previous <- previous
+  slimeConnection$istate$content <- emacsInspect(object)
+  if(!(vectorify(object) %in% slimeConnection$inspectorHistory)) {
+    slimeConnection$inspectorHistory <- c(slimeConnection$inspectorHistory, object)
+  }
+  if(!is.null(slimeConnection$istate$previous)) {
+    slimeConnection$istate$previous$`next` <- slimeConnection$istate
+  }
+  istateToElisp(slimeConnection$istate)
+}
+
+valuePart <- function(istate, object, string) {
+  list(quote(`:value`),
+       if(is.null(string)) prin1ToString(object) else string,
+       assignIndexInParts(object, istate))
+}
+
+preparePart <- function(istate, part) {
+  if(is.character(part)) {
+    list(part)
+  } else {
+    switch(as.character(part[[1]]),
+           `:newline` = list("\n"),
+           `:value` = valuePart(istate, part[[2]], part[[3]]),
+           `:line` = list(prin1ToString(part[[2]]), ": ",
+             valuePart(istate, part[[3]], NULL), "\n"))
+  }
+}
+
+prepareRange <- function(istate, start, end) {
+  range <- istate$content[start+1:min(end+1, length(istate$content))]
+  ps <- NULL
+  for(part in range) {
+    ps <- c(ps, preparePart(istate, part))
+  }
+  list(ps, if(length(ps)<end-start) { start+length(ps) } else { end+1000 },
+       start, end)
+}
+
+assignIndexInParts <- function(object, istate) {
+  ret <- 1+length(istate$parts)
+  istate$parts <- c(istate$parts, list(object))
+  ret
+}
+
+istateToElisp <- function(istate) {
+  list(quote(`:title`), deparse(istate$object, control="all", nlines=1),
+       quote(`:id`), assignIndexInParts(istate$object, istate),
+       quote(`:content`), prepareRange(istate, 0, 500))
+}
+
+emacsInspect <- function(object) {
+  UseMethod("emacsInspect")
+}
+
+emacsInspect.default <- function(thing) {
+  c(list(paste("a ", class(thing)[[1]], sep=""), list(quote(`:newline`))))
+}
+
+emacsInspect.list <- function(list) {
+  c(list("a list", list(quote(`:newline`))),
+    mapply(function(name, value) { list(list(quote(`:line`), name, value)) },
+           names(list), list))
+}
+
+emacsInspect.numeric <- function(numeric) {
+  c(list("a numeric", list(quote(`:newline`))),
+    mapply(function(name, value) { list(list(quote(`:line`), name, value)) },
+           (1:length(numeric)), numeric))
+}
+
+`swank:quit-inspector` <- function(slimeConnection, sldbState) {
+  resetInspector(slimeConnection)
+  FALSE
+}
+
+`swank:inspector-nth-part` <- function(slimeConnection, sldbState, index) {
+  slimeConnection$istate$parts[[index]]
+}
+
+`swank:inspect-nth-part` <- function(slimeConnection, sldbState, index) {
+  object <- `swank:inspector-nth-part`(slimeConnection, sldbState, index)
+  inspectObject(slimeConnection, object)
+}
+
+`swank:inspector-pop` <- function(slimeConnection, sldbState) {
+  if(!is.null(slimeConnection$istate$previous)) {
+    slimeConnection$istate <- slimeConnection$istate$previous
+    istateToElisp(slimeConnection$istate)
+  } else {
+    FALSE
+  }
+}
+
+`swank:inspector-next` <- function(slimeConnection, sldbState) {
+  if(!is.null(slimeConnection$istate$`next`)) {
+    slimeConnection$istate <- slimeConnection$istate$`next`
+    istateToElisp(slimeConnection$istate)
+  } else {
+    FALSE
+  }
+}
+
+`swank:inspector-eval` <- function(slimeConnection, sldbState, string) {
+  expr <- parse(text=string)[[1]]
+  object <- slimeConnection$istate$object
+  if(inherits(object, "list")|inherits(object, "environment")) {
+    substituted <- substituteDirect(expr, object)
+    eval(substituted, envir=globalenv())
+  } else {
+    eval(expr, envir=globalenv())
+  }
+}
+
+`swank:inspect-current-condition` <- function(slimeConnection, sldbState) {
+  resetInspector(slimeConnection)
+  inspectObject(slimeConnection, sldbState$condition)
+}
+
+`swank:inspect-frame-var` <- function(slimeConnection, sldbState, frame, var) {
+  resetInspector(slimeConnection)
+  frame <- sldbState$frames[[1+frame]]
+  name <- ls(envir=frame)[[1+var]]
+  object <- get(name, envir=frame)
+  inspectObject(slimeConnection, object)
+}
+
+`swank:default-directory` <- function(slimeConnection, sldbState) {
+  getwd()
+}
+
+`swank:set-default-directory` <- function(slimeConnection, sldbState, directory) {
+  setwd(directory)
+  `swank:default-directory`(slimeConnection, sldbState)
+}
+
+`swank:load-file` <- function(slimeConnection, sldbState, filename) {
+  source(filename, local=FALSE, keep.source=TRUE)
+  TRUE
+}
+
+`swank:compile-file-for-emacs` <- function(slimeConnection, sldbState, filename, loadp, ...) {
+  times <- system.time(parse(filename, srcfile=srcfile(filename)))
+  if(loadp) {
+    ## KLUDGE: inelegant, but works.  It might be more in the spirit
+    ## of things to keep the result of the parse above around to
+    ## evaluate.
+    `swank:load-file`(slimeConnection, sldbState, filename)
+  }
+  list(quote(`:compilation-result`), list(), TRUE, times[3], substitute(loadp), filename)
+}
+
+`swank:quit-lisp` <- function(slimeConnection, sldbState) {
+  quit()
+}