MAP primitive variant for linked lists

2 files changed, 59 insertions, 9 deletions

diff --git a/history.txt b/history.txt
index 9525554..4d26412 100755
--- a/history.txt
+++ b/history.txt
@@ -1946,3 +1946,7 @@ ______
 * Lists: fixed type-issue for linked list indices (thanks, Nate, for reporting it!)
 * Threads, Objects: experimental MAP primitive reporter in lists category, visible in dev mode
 * Blocks: fixed #199 (can't delete reporter with attached comment via context menu)
+
+131009
+------
+* Theads: added a variant for linked lists to the experimental MAP primitive reporter
diff --git a/threads.js b/threads.js
index ee28e59..8b0e25b 100644
--- a/threads.js
+++ b/threads.js
@@ -83,7 +83,7 @@ ArgLabelMorph, localize, XML_Element, hex_sha512*/
 
 // Global stuff ////////////////////////////////////////////////////////
 
-modules.threads = '2013-October-08';
+modules.threads = '2013-October-09';
 
 var ThreadManager;
 var Process;
@@ -1516,15 +1516,61 @@ Process.prototype.doWaitUntil = function (goalCondition) {
 };
 
 Process.prototype.reportMap = function (reporter, list) {
-    if (this.context.inputs.length - 2 === list.length()) {
-        this.returnValueToParentContext(
-            new List(this.context.inputs.slice(2))
-        );
-        return;
+    // answer a new list containing the results of the reporter applied
+    // to each value of the given list. Distinguish between linked and
+    // arrayed lists.
+    // Note: This method utilizes the current context's inputs array to
+    // manage temporary variables, whose allocation to which slot are
+    // documented in each of the variants' code (linked or arrayed) below
+
+    var next;
+    if (list.isLinked) {
+        // this.context.inputs:
+        // [0] - reporter
+        // [1] - list (original source)
+        // -----------------------------
+        // [2] - result list (target)
+        // [3] - currently last element of result list
+        // [4] - current source list (what's left to map)
+        // [5] - current value of last function call
+
+        if (this.context.inputs.length < 3) {
+            this.context.addInput(new List());
+            this.context.inputs[2].isLinked = true;
+            this.context.addInput(this.context.inputs[2]);
+            this.context.addInput(list);
+        }
+        if (this.context.inputs[4].length() === 0) {
+            this.context.inputs[3].rest = list.cons(this.context.inputs[5]);
+            this.returnValueToParentContext(this.context.inputs[2].cdr());
+            return;
+        }
+        if (this.context.inputs.length > 5) {
+            this.context.inputs[3].rest = list.cons(this.context.inputs[5]);
+            this.context.inputs[3] = this.context.inputs[3].rest;
+            this.context.inputs.splice(5);
+        }
+        next = this.context.inputs[4].at(1);
+        this.context.inputs[4] = this.context.inputs[4].cdr();
+        this.pushContext();
+        this.evaluate(reporter, new List([next]));
+    } else { // arrayed
+        // this.context.inputs:
+        // [0] - reporter
+        // [1] - list (original source)
+        // -----------------------------
+        // [2..n] - result values (target)
+
+        if (this.context.inputs.length - 2 === list.length()) {
+            this.returnValueToParentContext(
+                new List(this.context.inputs.slice(2))
+            );
+            return;
+        }
+        next = list.at(this.context.inputs.length - 1);
+        this.pushContext();
+        this.evaluate(reporter, new List([next]));
     }
-    var next = list.at(this.context.inputs.length - 1);
-    this.pushContext();
-    this.evaluate(reporter, new List([next]));
 };
 
 // Process interpolated primitives