swank.R

   1 ### This program is free software; you can redistribute it and/or
   2 ### modify it under the terms of the GNU General Public Licence as
   3 ### published by the Free Software Foundation; either version 2 of the
   4 ### Licence, or (at your option) any later version.
   5 ###
   6 ### This program is distributed in the hope that it will be useful,
   7 ### but WITHOUT ANY WARRANTY; without even the implied warranty of
   8 ### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9 ### GNU General Public Licence for more details.
  10 ###
  11 ### A copy of version 2 of the GNU General Public Licence is available
  12 ### at <http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt>; the
  13 ### latest version of the GNU General Public Licence is available at
  14 ### <http://www.gnu.org/licenses/gpl.txt>.
  15
  16 ### KLUDGE: this assumes that we're being sourced with chdir=TRUE.
  17 ### (If not, `swank:swank-require` will work under the circumstances
  18 ### that it used to work anyway -- i.e. the working directory is the
  19 ### swankr directory)
  20 swankrPath <- getwd()
  21
  22 swank <- function(port=4005) {
  23   acceptConnections(port, FALSE)
  24 }
  25
  26 startSwank <- function(portFile) {
  27   acceptConnections(4005, portFile)
  28 }
  29
  30 acceptConnections <- function(port, portFile) {
  31   if(portFile != FALSE) {
  32     f <- file(portFile, open="w+")
  33     cat(port, file=f)
  34     close(f)
  35   }
  36   ## FIXME: maybe we should support dontClose here?
  37   s <- socketConnection(host="localhost", server=TRUE, port=port, open="r+b")
  38   on.exit(close(s))
  39   tryCatch(serve(s), endOfFile=function(c) NULL)
  40 }
  41
  42 serve <- function(io) {
  43   mainLoop(io)
  44 }
  45
  46 mainLoop <- function(io) {
  47   slimeConnection <- new.env()
  48   slimeConnection$io <- io
  49   while(TRUE) {
  50     withRestarts(tryCatch(dispatch(slimeConnection, readPacket(io)),
  51                           swankTopLevel=function(c) NULL),
  52                  abort="return to SLIME's toplevel")
  53   }
  54 }
  55
  56 dispatch <- function(slimeConnection, event, sldbState=NULL) {
  57   kind <- event[[1]]
  58   if(kind == quote(`:emacs-rex`)) {
  59     do.call("emacsRex", c(list(slimeConnection), list(sldbState), event[-1]))
  60   }
  61 }
  62
  63 sendToEmacs <- function(slimeConnection, obj) {
  64   io <- slimeConnection$io
  65   payload <- writeSexpToString(obj)
  66   writeChar(sprintf("%06x", nchar(payload, type="bytes")), io, eos=NULL)
  67   writeChar(payload, io, eos=NULL)
  68   flush(io)
  69 }
  70
  71 callify <- function(form) {
  72   ## we implement here the conversion from Lisp S-expression (or list)
  73   ## expressions of code into our own, swankr, calling convention,
  74   ## with slimeConnection and sldbState as first and second arguments.
  75   ## as.call() gets us part of the way, but we need to walk the list
  76   ## recursively to mimic CL:EVAL; we need to avoid converting R
  77   ## special operators which we are punning (only `quote`, for now)
  78   ## into this calling convention.
  79   if(is.list(form)) {
  80     if(form[[1]] == quote(quote)) {
  81       as.call(form)
  82     } else {
  83       as.call(c(list(form[[1]], quote(slimeConnection), quote(sldbState)), lapply(form[-1], callify)))
  84     }
  85   } else {
  86     form
  87   }
  88 }
  89
  90 emacsRex <- function(slimeConnection, sldbState, form, pkg, thread, id, level=0) {
  91   ok <- FALSE
  92   value <- NULL
  93   conn <- textConnection(NULL, open="w")
  94   condition <- NULL
  95   tryCatch({
  96     withCallingHandlers({
  97       call <- callify(form)
  98       capture.output(value <- eval(call), file=conn)
  99       string <- paste(textConnectionValue(conn), sep="", collapse="\n")
 100       if(nchar(string) > 0) {
 101         sendToEmacs(slimeConnection, list(quote(`:write-string`), string))
 102         sendToEmacs(slimeConnection, list(quote(`:write-string`), "\n"))
 103       }
 104       close(conn)
 105       ok <- TRUE
 106     }, error=function(c) {
 107       condition <<- c
 108       string <- paste(textConnectionValue(conn), sep="", collapse="\n")
 109       if(nchar(string) > 0) {
 110         sendToEmacs(slimeConnection, list(quote(`:write-string`), string))
 111         sendToEmacs(slimeConnection, list(quote(`:write-string`), "\n"))
 112       }
 113       close(conn)
 114       newSldbState <- makeSldbState(c, if(is.null(sldbState)) 0 else sldbState$level+1, id)
 115       withRestarts(sldbLoop(slimeConnection, newSldbState, id), abort=paste("return to sldb level", newSldbState$level)) })},
 116     finally=sendToEmacs(slimeConnection, list(quote(`:return`), if(ok) list(quote(`:ok`), value) else list(quote(`:abort`), as.character(condition)), id)))
 117 }
 118
 119 makeSldbState <- function(condition, level, id) {
 120   calls <- rev(sys.calls())[-1]
 121   frames <- rev(sys.frames())[-1]
 122   restarts <- rev(computeRestarts(condition))[-1]
 123   ret <- list(condition=condition, level=level, id=id, restarts=restarts, calls=calls, frames=frames)
 124   class(ret) <- c("sldbState", class(ret))
 125   ret
 126 }
 127
 128 sldbLoop <- function(slimeConnection, sldbState, id) {
 129   tryCatch({
 130     io <- slimeConnection$io
 131     sendToEmacs(slimeConnection, c(list(quote(`:debug`), id, sldbState$level), `swank:debugger-info-for-emacs`(slimeConnection, sldbState)))
 132     sendToEmacs(slimeConnection, list(quote(`:debug-activate`), id, sldbState$level, FALSE))
 133     while(TRUE) {
 134       dispatch(slimeConnection, readPacket(io), sldbState)
 135     }
 136   }, finally=sendToEmacs(slimeConnection, c(list(quote(`:debug-return`), id, sldbState$level, FALSE))))
 137 }
 138
 139 readPacket <- function(io) {
 140   socketSelect(list(io))
 141   header <- readChunk(io, 6)
 142   len <- strtoi(header, base=16)
 143   payload <- readChunk(io, len)
 144   readSexpFromString(payload)
 145 }
 146
 147 readChunk <- function(io, len) {
 148   buffer <- readChar(io, len)
 149   if(length(buffer) == 0) {
 150     condition <- simpleCondition("End of file on io")
 151     class(condition) <- c("endOfFile", class(condition))
 152     signalCondition(condition)
 153   }
 154   if(nchar(buffer) != len) {
 155     stop("short read in readChunk")
 156   }
 157   buffer
 158 }
 159
 160 readSexpFromString <- function(string) {
 161   pos <- 1
 162   read <- function() {
 163     skipWhitespace()
 164     char <- substr(string, pos, pos)
 165     switch(char,
 166            "("=readList(),
 167            "\""=readString(),
 168            "'"=readQuote(),
 169            {
 170              if(pos > nchar(string))
 171                stop("EOF during read")
 172              obj <- readNumberOrSymbol()
 173              if(obj == quote(`.`)) {
 174                stop("Consing dot not implemented")
 175              }
 176              obj
 177            })
 178   }
 179   skipWhitespace <- function() {
 180     while(substr(string, pos, pos) %in% c(" ", "\t", "\n")) {
 181       pos <<- pos + 1
 182     }
 183   }
 184   readList <- function() {
 185     ret <- list()
 186     pos <<- pos + 1
 187     while(TRUE) {
 188       skipWhitespace()
 189       char <- substr(string, pos, pos)
 190       if(char == ")") {
 191         pos <<- pos + 1
 192         break
 193       } else {
 194         obj <- read()
 195         if(length(obj) == 1 && obj == quote(`.`)) {
 196           stop("Consing dot not implemented")
 197         }
 198         ret <- c(ret, list(obj))
 199       }
 200     }
 201     ret
 202   }
 203   readString <- function() {
 204     ret <- ""
 205     addChar <- function(c) { ret <<- paste(ret, c, sep="") }
 206     while(TRUE) {
 207       pos <<- pos + 1
 208       char <- substr(string, pos, pos)
 209       switch(char,
 210              "\""={ pos <<- pos + 1; break },
 211              "\\"={ pos <<- pos + 1
 212                     char2 <- substr(string, pos, pos)
 213                     switch(char2,
 214                            "\""=addChar(char2),
 215                            "\\"=addChar(char2),
 216                            stop("Unrecognized escape character")) },
 217              addChar(char))
 218     }
 219     ret
 220   }
 221   readNumberOrSymbol <- function() {
 222     token <- readToken()
 223     if(nchar(token)==0) {
 224       stop("End of file reading token")
 225     } else if(grepl("^[0-9]+$", token)) {
 226       strtoi(token)
 227     } else if(grepl("^[0-9]+\\.[0-9]+$", token)) {
 228       as.double(token)
 229     } else {
 230       name <- as.name(token)
 231       if(name == quote(t)) {
 232         TRUE
 233       } else if(name == quote(nil)) {
 234         FALSE
 235       } else {
 236         name
 237       }
 238     }
 239   }
 240   readToken <- function() {
 241     token <- ""
 242     while(TRUE) {
 243       char <- substr(string, pos, pos)
 244       if(char == "") {
 245         break;
 246       } else if(char %in% c(" ", "\n", "\t", "(", ")", "\"", "'")) {
 247         break;
 248       } else {
 249         token <- paste(token, char, sep="")
 250         pos <<- pos + 1
 251       }
 252     }
 253     token
 254   }
 255   read()
 256 }
 257
 258 writeSexpToString <- function(obj) {
 259   writeSexpToStringLoop <- function(obj) {
 260     switch(typeof(obj),
 261            "character"={ string <- paste(string, "\"", gsub("([\"\\])", "\\\\\\1", obj), "\"", sep="") },
 262            "list"={ string <- paste(string, "(", sep="")
 263                     max <- length(obj)
 264                     if(max > 0) {
 265                       for(i in 1:max) {
 266                         string <- paste(string, writeSexpToString(obj[[i]]), sep="")
 267                         if(i != max) {
 268                           string <- paste(string, " ", sep="")
 269                         }
 270                       }
 271                     }
 272                     string <- paste(string, ")", sep="") },
 273            "symbol"={ string <- paste(string, as.character(obj), sep="") },
 274            "logical"={ string <- if(obj) { paste(string, "t", sep="") } else { paste(string, "nil", sep="") }},
 275            "double"={ string <- paste(string, as.character(obj), sep="") },
 276            "integer"={ string <- paste(string, as.character(obj), sep="") },
 277            stop(paste("can't write object ", obj, sep="")))
 278     string
 279   }
 280   string <- ""
 281   writeSexpToStringLoop(obj)
 282 }
 283
 284 prin1ToString <- function(val) {
 285   paste(deparse(val, backtick=TRUE, control=c("delayPromises", "keepNA")),
 286         sep="", collapse="\n")
 287 }
 288
 289 printToString <- function(val) {
 290   paste(capture.output(print(val)), sep="", collapse="\n")
 291 }
 292
 293 `swank:connection-info` <- function (slimeConnection, sldbState) {
 294   list(quote(`:pid`), Sys.getpid(),
 295        quote(`:package`), list(quote(`:name`), "R", quote(`:prompt`), "R> "),
 296        quote(`:encoding`), list(quote(`:coding-systems`), list("utf-8-unix")),
 297        quote(`:lisp-implementation`), list(quote(`:type`), "R",
 298                                            quote(`:name`), "R",
 299                                            quote(`:version`), paste(R.version$major, R.version$minor, sep=".")))
 300 }
 301
 302 `swank:swank-require` <- function (slimeConnection, sldbState, contribs) {
 303   for(contrib in contribs) {
 304     filename <- sprintf("%s/%s.R", swankrPath, as.character(contrib))
 305     if(file.exists(filename)) {
 306       source(filename)
 307     }
 308   }
 309   list()
 310 }
 311
 312 `swank:create-repl` <- function(slimeConnection, sldbState, env, ...) {
 313   list("R", "R")
 314 }
 315
 316 makeReplResult <- function(value) {
 317   string <- printToString(value)
 318   list(quote(`:write-string`), string,
 319        quote(`:repl-result`))
 320 }
 321
 322 makeReplResultFunction <- makeReplResult
 323
 324 sendReplResult <- function(slimeConnection, value) {
 325   result <- makeReplResultFunction(value)
 326   sendToEmacs(slimeConnection, result)
 327 }
 328
 329 sendReplResultFunction <- sendReplResult
 330
 331 `swank:listener-eval` <- function(slimeConnection, sldbState, string) {
 332   ## O how ugly
 333   string <- gsub("#\\.\\(swank:lookup-presented-object-or-lose([^)]*)\\)", ".(`swank:lookup-presented-object-or-lose`(slimeConnection, sldbState,\\1))", string)
 334   for(expr in parse(text=string)) {
 335     expr <- expr
 336     ## O maybe this is even uglier
 337     lookedup <- do.call("bquote", list(expr))
 338     tmp <- withVisible(eval(lookedup, envir = globalenv()))
 339     if(tmp$visible) {
 340       sendReplResultFunction(slimeConnection, tmp$value)
 341     }
 342   }
 343   list()
 344 }
 345
 346 `swank:autodoc` <- function(slimeConnection, sldbState, rawForm, ...) {
 347   "No Arglist Information"
 348 }
 349
 350 `swank:operator-arglist` <- function(slimeConnection, sldbState, op, package) {
 351   list()
 352 }
 353
 354 `swank:throw-to-toplevel` <- function(slimeConnection, sldbState) {
 355   condition <- simpleCondition("Throw to toplevel")
 356   class(condition) <- c("swankTopLevel", class(condition))
 357   signalCondition(condition)
 358 }
 359
 360 `swank:backtrace` <- function(slimeConnection, sldbState, from=0, to=NULL) {
 361   calls <- sldbState$calls
 362   if(is.null(to)) to <- length(calls)
 363   from <- from+1
 364   calls <- lapply(calls[from:to],
 365                   { frameNumber <- from-1;
 366                     function (x) {
 367                       ret <- list(frameNumber, paste(format(x), sep="", collapse=" "))
 368                       frameNumber <<- 1+frameNumber
 369                       ret
 370                     }
 371                   })
 372 }
 373
 374 computeRestartsForEmacs <- function (sldbState) {
 375   lapply(sldbState$restarts,
 376          function(x) {
 377            ## this is all a little bit internalsy
 378            restartName <- x[[1]][[1]]
 379            description <- restartDescription(x)
 380            list(restartName, if(is.null(description)) restartName else description)
 381          })
 382 }
 383
 384 `swank:debugger-info-for-emacs` <- function(slimeConnection, sldbState, from=0, to=NULL) {
 385   list(list(as.character(sldbState$condition), sprintf("  [%s]", class(sldbState$condition)[[1]]), FALSE),
 386        computeRestartsForEmacs(sldbState),
 387        `swank:backtrace`(slimeConnection, sldbState, from, to),
 388        list(sldbState$id))
 389 }
 390
 391 `swank:invoke-nth-restart-for-emacs` <- function(slimeConnection, sldbState, level, n) {
 392   if(sldbState$level == level) {
 393     invokeRestart(sldbState$restarts[[n+1]])
 394   }
 395 }
 396
 397 `swank:frame-source-location` <- function(slimeConnection, sldbState, n) {
 398   call <- sldbState$calls[[n+1]]
 399   srcref <- attr(call, "srcref")
 400   srcfile <- attr(srcref, "srcfile")
 401   if(is.null(srcfile)) {
 402     list(quote(`:error`), "no srcfile")
 403   } else {
 404     filename <- get("filename", srcfile)
 405     ## KLUDGE: what this means is "is the srcfile filename
 406     ## absolute?"
 407     if(substr(filename, 1, 1) == "/") {
 408       file <- filename
 409     } else {
 410       file <- sprintf("%s/%s", srcfile$wd, filename)
 411     }
 412     list(quote(`:location`),
 413          list(quote(`:file`), file),
 414          list(quote(`:line`), srcref[[1]], srcref[[2]]-1),
 415          FALSE)
 416   }
 417 }
 418
 419 `swank:buffer-first-change` <- function(slimeConnection, sldbState, filename) {
 420   FALSE
 421 }
 422
 423 `swank:eval-string-in-frame` <- function(slimeConnection, sldbState, string, index) {
 424   frame <- sldbState$frames[[1+index]]
 425   withRetryRestart("retry SLIME interactive evaluation request",
 426                    value <- eval(parse(text=string), envir=frame))
 427   printToString(value)
 428 }
 429
 430 `swank:frame-locals-and-catch-tags` <- function(slimeConnection, sldbState, index) {
 431   frame <- sldbState$frames[[1+index]]
 432   objs <- ls(envir=frame)
 433   if(identical(frame, globalenv())) {
 434     objs <- c()
 435   }
 436   list(lapply(objs, function(name) { list(quote(`:name`), name,
 437                                           quote(`:id`), 0,
 438                                           quote(`:value`),
 439                                           tryCatch({
 440                                             printToString(eval(parse(text=name), envir=frame))
 441                                           }, error=function(c) {
 442                                             sprintf("error printing object")
 443                                           }))}),
 444        list())
 445 }
 446
 447 `swank:simple-completions` <- function(slimeConnection, sldbState, prefix, package) {
 448   literal2rx <- function(string) {
 449     ## list of ERE metacharacters from ?regexp
 450     gsub("([.\\|()[{^$*+?])", "\\\\\\1", string)
 451   }
 452   matches <- apropos(sprintf("^%s", literal2rx(prefix)), ignore.case=FALSE)
 453   nmatches <- length(matches)
 454   if(nmatches == 0) {
 455     list(list(), "")
 456   } else {
 457     longest <- matches[order(nchar(matches))][1]
 458     while(length(grep(sprintf("^%s", literal2rx(longest)), matches)) < nmatches) {
 459       longest <- substr(longest, 1, nchar(longest)-1)
 460     }
 461     list(as.list(matches), longest)
 462   }
 463 }
 464
 465 `swank:compile-string-for-emacs` <- function(slimeConnection, sldbState, string, buffer, position, filename, policy) {
 466   lineOffset <- charOffset <- colOffset <- NULL
 467   for(pos in position) {
 468     switch(as.character(pos[[1]]),
 469            `:position` = {charOffset <- pos[[2]]},
 470            `:line` = {lineOffset <- pos[[2]]; colOffset <- pos[[3]]},
 471            warning("unknown content in pos", pos))
 472   }
 473   frob <- function(refs) {
 474     lapply(refs,
 475            function(x)
 476            srcref(attr(x,"srcfile"),
 477                   c(x[1]+lineOffset-1, ifelse(x[1]==1, x[2]+colOffset-1, x[2]),
 478                     x[3]+lineOffset-1, ifelse(x[3]==1, x[4]+colOffset-1, x[4]),
 479                     ifelse(x[1]==1, x[5]+colOffset-1, x[5]),
 480                     ifelse(x[3]==1, x[6]+colOffset-1, x[6]))))
 481   }
 482   transformSrcrefs <- function(s) {
 483     srcrefs <- attr(s, "srcref")
 484     attribs <- attributes(s)
 485     new <-
 486       switch(mode(s),
 487              "call"=as.call(lapply(s, transformSrcrefs)),
 488              "expression"=as.expression(lapply(s, transformSrcrefs)),
 489              s)
 490     attributes(new) <- attribs
 491     if(!is.null(attr(s, "srcref"))) {
 492       attr(new, "srcref") <- frob(srcrefs)
 493     }
 494     new
 495   }
 496   withRestarts({
 497     times <- system.time({
 498       exprs <- parse(text=string, srcfile=srcfile(filename))
 499       eval(transformSrcrefs(exprs), envir = globalenv()) })},
 500                abort="abort compilation")
 501   list(quote(`:compilation-result`), list(), TRUE, times[3], FALSE, FALSE)
 502 }
 503
 504 withRetryRestart <- function(description, expr) {
 505   call <- substitute(expr)
 506   retry <- TRUE
 507   while(retry) {
 508     retry <- FALSE
 509     withRestarts(eval.parent(call),
 510                  retry=list(description=description,
 511                    handler=function() retry <<- TRUE))
 512   }
 513 }
 514
 515 `swank:interactive-eval` <-  function(slimeConnection, sldbState, string) {
 516   withRetryRestart("retry SLIME interactive evaluation request",
 517                    tmp <- withVisible(eval(parse(text=string), envir=globalenv())))
 518   if(tmp$visible) {
 519     prin1ToString(tmp$value)
 520   } else {
 521     "# invisible value"
 522   }
 523 }
 524
 525 `swank:eval-and-grab-output` <- function(slimeConnection, sldbState, string) {
 526   withRetryRestart("retry SLIME interactive evaluation request",
 527                    { output <-
 528                        capture.output(tmp <- withVisible(eval(parse(text=string),
 529                                                               envir=globalenv()))) })
 530   output <- paste(output, sep="", collapse="\n")
 531   if(tmp$visible) {
 532     list(output, prin1ToString(tmp$value))
 533   } else {
 534     list(output, "# invisible value")
 535   }
 536 }
 537
 538 `swank:interactive-eval-region` <- function(slimeConnection, sldbState, string) {
 539   withRetryRestart("retry SLIME interactive evaluation request",
 540                    tmp <- withVisible(eval(parse(text=string), envir=globalenv())))
 541   if(tmp$visible) {
 542     prin1ToString(tmp$value)
 543   } else {
 544     "# invisible value"
 545   }
 546 }
 547
 548 `swank:find-definitions-for-emacs` <- function(slimeConnection, sldbState, string) {
 549   if(exists(string, envir = globalenv())) {
 550     thing <- get(string, envir = globalenv())
 551     if(inherits(thing, "function")) {
 552       body <- body(thing)
 553       srcref <- attr(body, "srcref")
 554       srcfile <- attr(body, "srcfile")
 555       if(is.null(srcfile)) {
 556         list()
 557       } else {
 558         filename <- get("filename", srcfile)
 559         ## KLUDGE: what this means is "is the srcfile filename
 560         ## absolute?"
 561         if(substr(filename, 1, 1) == "/") {
 562           file <- filename
 563         } else {
 564           file <- sprintf("%s/%s", srcfile$wd, filename)
 565         }
 566         list(list(sprintf("function %s", string),
 567                   list(quote(`:location`),
 568                        list(quote(`:file`), file),
 569                        list(quote(`:line`), srcref[[2]][[1]], srcref[[2]][[2]]-1),
 570                        list())))
 571       }
 572     } else {
 573       list()
 574     }
 575   } else {
 576     list()
 577   }
 578 }
 579
 580 `swank:value-for-editing` <- function(slimeConnection, sldbState, string) {
 581   paste(deparse(eval(parse(text=string), envir = globalenv()), control="all"),
 582         collapse="\n", sep="")
 583 }
 584
 585 `swank:commit-edited-value` <- function(slimeConnection, sldbState, string, value) {
 586   eval(parse(text=sprintf("%s <- %s", string, value)), envir = globalenv())
 587   TRUE
 588 }
 589
 590 resetInspector <- function(slimeConnection) {
 591   assign("istate", list(), envir=slimeConnection)
 592   assign("inspectorHistory", NULL, envir=slimeConnection)
 593 }
 594
 595 `swank:init-inspector` <- function(slimeConnection, sldbState, string) {
 596   withRetryRestart("retry SLIME inspection request",
 597                    { resetInspector(slimeConnection)
 598                      value <- inspectObject(slimeConnection, eval(parse(text=string), envir=globalenv()))
 599                    })
 600   value
 601 }
 602
 603 inspectObject <- function(slimeConnection, object) {
 604   previous <- slimeConnection$istate
 605   slimeConnection$istate <- new.env()
 606   slimeConnection$istate$object <- object
 607   slimeConnection$istate$previous <- previous
 608   slimeConnection$istate$content <- emacsInspect(object)
 609   if(!(object %in% slimeConnection$inspectorHistory)) {
 610     slimeConnection$inspectorHistory <- c(slimeConnection$inspectorHistory, object)
 611   }
 612   if(!is.null(slimeConnection$istate$previous)) {
 613     slimeConnection$istate$previous$`next` <- slimeConnection$istate
 614   }
 615   istateToElisp(slimeConnection$istate)
 616 }
 617
 618 valuePart <- function(istate, object, string) {
 619   list(quote(`:value`),
 620        if(is.null(string)) printToString(object) else string,
 621        assignIndexInParts(object, istate))
 622 }
 623
 624 preparePart <- function(istate, part) {
 625   if(is.character(part)) {
 626     list(part)
 627   } else {
 628     switch(as.character(part[[1]]),
 629            `:newline` = list("\n"),
 630            `:value` = valuePart(istate, part[[2]], part[[3]]),
 631            `:line` = list(printToString(part[[2]]), ": ",
 632              valuePart(istate, part[[3]], NULL), "\n"))
 633   }
 634 }
 635
 636 prepareRange <- function(istate, start, end) {
 637   range <- istate$content[start+1:min(end+1, length(istate$content))]
 638   ps <- NULL
 639   for(part in range) {
 640     ps <- c(ps, preparePart(istate, part))
 641   }
 642   list(ps, if(length(ps)<end-start) { start+length(ps) } else { end+1000 },
 643        start, end)
 644 }
 645
 646 assignIndexInParts <- function(object, istate) {
 647   ret <- 1+length(istate$parts)
 648   istate$parts <- c(istate$parts, list(object))
 649   ret
 650 }
 651
 652 istateToElisp <- function(istate) {
 653   list(quote(`:title`), deparse(istate$object, control="all", nlines=1),
 654        quote(`:id`), assignIndexInParts(istate$object, istate),
 655        quote(`:content`), prepareRange(istate, 0, 500))
 656 }
 657
 658 emacsInspect <- function(object) {
 659   UseMethod("emacsInspect")
 660 }
 661
 662 emacsInspect.default <- function(thing) {
 663   c(list(paste("a ", class(thing)[[1]], sep=""), list(quote(`:newline`))))
 664 }
 665
 666 emacsInspect.list <- function(list) {
 667   c(list("a list", list(quote(`:newline`))),
 668     mapply(function(name, value) { list(list(quote(`:line`), name, value)) },
 669            names(list), list))
 670 }
 671
 672 emacsInspect.numeric <- function(numeric) {
 673   c(list("a numeric", list(quote(`:newline`))),
 674     mapply(function(name, value) { list(list(quote(`:line`), name, value)) },
 675            (1:length(numeric)), numeric))
 676 }
 677
 678 `swank:quit-inspector` <- function(slimeConnection, sldbState) {
 679   resetInspector(slimeConnection)
 680   FALSE
 681 }
 682
 683 `swank:inspector-nth-part` <- function(slimeConnection, sldbState, index) {
 684   slimeConnection$istate$parts[[index]]
 685 }
 686
 687 `swank:inspect-nth-part` <- function(slimeConnection, sldbState, index) {
 688   object <- `swank:inspector-nth-part`(slimeConnection, sldbState, index)
 689   inspectObject(slimeConnection, object)
 690 }
 691
 692 `swank:inspector-pop` <- function(slimeConnection, sldbState) {
 693   if(!is.null(slimeConnection$istate$previous)) {
 694     slimeConnection$istate <- slimeConnection$istate$previous
 695     istateToElisp(slimeConnection$istate)
 696   } else {
 697     FALSE
 698   }
 699 }
 700
 701 `swank:inspector-next` <- function(slimeConnection, sldbState) {
 702   if(!is.null(slimeConnection$istate$`next`)) {
 703     slimeConnection$istate <- slimeConnection$istate$`next`
 704     istateToElisp(slimeConnection$istate)
 705   } else {
 706     FALSE
 707   }
 708 }
 709
 710 `swank:inspector-eval` <- function(slimeConnection, sldbState, string) {
 711   expr <- parse(text=string)[[1]]
 712   object <- slimeConnection$istate$object
 713   if(inherits(object, "list")|inherits(object, "environment")) {
 714     substituted <- substituteDirect(expr, object)
 715     eval(substituted, envir=globalenv())
 716   } else {
 717     eval(expr, envir=globalenv())
 718   }
 719 }
 720
 721 `swank:inspect-current-condition` <- function(slimeConnection, sldbState) {
 722   resetInspector(slimeConnection)
 723   inspectObject(slimeConnection, sldbState$condition)
 724 }
 725
 726 `swank:inspect-frame-var` <- function(slimeConnection, sldbState, frame, var) {
 727   resetInspector(slimeConnection)
 728   frame <- sldbState$frames[[1+frame]]
 729   name <- ls(envir=frame)[[1+var]]
 730   object <- get(name, envir=frame)
 731   inspectObject(slimeConnection, object)
 732 }
 733
 734 `swank:default-directory` <- function(slimeConnection, sldbState) {
 735   getwd()
 736 }
 737
 738 `swank:set-default-directory` <- function(slimeConnection, sldbState, directory) {
 739   setwd(directory)
 740   `swank:default-directory`(slimeConnection, sldbState)
 741 }
 742
 743 `swank:load-file` <- function(slimeConnection, sldbState, filename) {
 744   source(filename, local=FALSE, keep.source=TRUE)
 745   TRUE
 746 }
 747
 748 `swank:compile-file-for-emacs` <- function(slimeConnection, sldbState, filename, loadp, ...) {
 749   times <- system.time(parse(filename, srcfile=srcfile(filename)))
 750   if(loadp) {
 751     ## KLUDGE: inelegant, but works.  It might be more in the spirit
 752     ## of things to keep the result of the parse above around to
 753     ## evaluate.
 754     `swank:load-file`(slimeConnection, sldbState, filename)
 755   }
 756   list(quote(`:compilation-result`), list(), TRUE, times[3], substitute(loadp), filename)
 757 }
 758
 759 `swank:quit-lisp` <- function(slimeConnection, sldbState) {
 760   quit()
 761 }