the beginnings of an inspector

Implement enough that C-c I begins to work, at least for values like
list(1,2,3).  The resulting inspector on the emacs side apparently has
no features, and an error message results on quitting the inspector
because I've only implemented `swank:init-inspector`, and not
`swank:quit-inspector`.  Still, good enough to checkpoint.

diff --git a/swank.R b/swank.R
index 22dd53286c467fc02abb8a162e942fb04f10c5d8..2d2bf779cdb126f8a62af59429d0156257bedc5f 100644 (file)
--- a/swank.R
+++ b/swank.R
@@ -460,3 +460,79 @@ withRetryRestart <- function(description, expr) {
   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) {
+  slimeConnection$istate <- list(object=object, previous=slimeConnection$istate)
+  slimeConnection$istate$content <- emacsInspect(object)
+  if(!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)) printToString(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(printToString(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$parts, object)
+  ret
+}
+
+istateToElisp <- function(istate) {
+  list(quote(`:title`), deparse(istate$object, control="all", nlines=1),
+       quote(`:id`), assignIndexInParts(istate$object, istate),
+       quote(`:content`), prepareRange(istate, 0, 500))
+}
+
+emacsInspect <- function(object) {
+  UseMethod("emacsInspect")
+}
+
+emacsInspect.list <- function(list) {
+  c(list("a list", list(quote(`:newline`))),
+    mapply(function(name, value) { list(list(quote(`:line`), name, value)) },
+           names(list), list))
+}
+