Index: sdk/lib/collection/iterable.dart |
diff --git a/sdk/lib/collection/iterable.dart b/sdk/lib/collection/iterable.dart |
index b6e52f4669e931320a443c262cd2208ca9668770..1ae7b9732d552f32f3988ed2f371b500d2be9194 100644 |
--- a/sdk/lib/collection/iterable.dart |
+++ b/sdk/lib/collection/iterable.dart |
@@ -195,7 +195,7 @@ abstract class IterableMixin<E> implements Iterable<E> { |
throw new RangeError.value(index); |
} |
- String toString() => _iterableToString(this); |
+ String toString() => IterableBase.iterableToShortString(this, '(', ')'); |
} |
/** |
@@ -402,138 +402,186 @@ abstract class IterableBase<E> implements Iterable<E> { |
* included from the start of the iterable. |
* |
* The conversion may omit calling `toString` on some elements if they |
- * are known to now occur in the output, and it may stop iterating after |
+ * are known to not occur in the output, and it may stop iterating after |
* a hundred elements. |
*/ |
- String toString() => _iterableToString(this); |
-} |
- |
-String _setToString(Set set) => _collectionToString(set, "{" , "}"); |
+ String toString() => iterableToShortString(this, '(', ')'); |
-String _iterableToString(Iterable iterable) => |
- _collectionToString(iterable, "(", ")"); |
+ /** |
+ * Convert an `Iterable` to a string like [IterableBase.toString]. |
+ * |
+ * Allows using other delimiters than '(' and ')'. |
+ * |
+ * Handles circular references where converting one of the elements |
+ * to a string ends up converting [iterable] to a string again. |
+ */ |
+ static String iterableToShortString(Iterable iterable, |
+ [String leftDelimiter = '(', |
+ String rightDelimiter = ')']) { |
+ if (_toStringVisiting.contains(iterable)) { |
+ if (leftDelimiter == "(" && rightDelimiter == ")") { |
+ // Avoid creating a new string in the "common" case. |
+ return "(...)"; |
+ } |
+ return "$leftDelimiter...$rightDelimiter"; |
+ } |
+ List parts = []; |
+ _toStringVisiting.add(iterable); |
+ try { |
+ _iterablePartsToStrings(iterable, parts); |
+ } finally { |
+ _toStringVisiting.remove(iterable); |
+ } |
+ return (new StringBuffer(leftDelimiter) |
+ ..writeAll(parts, ", ") |
+ ..write(rightDelimiter)).toString(); |
+ } |
-String _collectionToString(Iterable iterable, String before, String after) { |
- if (_toStringVisiting.contains(iterable)) return "$before...$after"; |
- _toStringVisiting.add(iterable); |
- List parts = []; |
- try { |
- _collectionPartsToStrings(iterable, parts); |
- } finally { |
- _toStringVisiting.remove(iterable); |
+ /** |
+ * Converts an `Iterable` to a string. |
+ * |
+ * Converts each elements to a string, and separates the results by ", ". |
+ * Then wraps the result in [leftDelimiter] and [rightDelimiter]. |
+ * |
+ * Unlike [iterableToShortString], this conversion doesn't omit any |
+ * elements or puts any limit on the size of the result. |
+ * |
+ * Handles circular references where converting one of the elements |
+ * to a string ends up converting [iterable] to a string again. |
+ */ |
+ static String iterableToFullString(Iterable iterable, |
+ [String leftDelimiter = '(', |
+ String rightDelimiter = ')']) { |
+ if (_toStringVisiting.contains(iterable)) { |
+ return "$leftDelimiter...$rightDelimiter"; |
+ } |
+ StringBuffer buffer = new StringBuffer(leftDelimiter); |
+ _toStringVisiting.add(iterable); |
+ try { |
+ buffer.writeAll(iterable, ", "); |
+ } finally { |
+ _toStringVisiting.remove(iterable); |
+ } |
+ buffer.write(rightDelimiter); |
+ return buffer.toString(); |
} |
- return (new StringBuffer(before) |
- ..writeAll(parts, ", ") |
- ..write(after)).toString(); |
-} |
-/** Convert elments of [iterable] to strings and store them in [parts]. */ |
-void _collectionPartsToStrings(Iterable iterable, List parts) { |
- /// Try to stay below this many characters. |
- const int LENGTH_LIMIT = 80; |
- /// Always at least this many elements at the start. |
- const int HEAD_COUNT = 3; |
- /// Always at least this many elements at the end. |
- const int TAIL_COUNT = 2; |
- /// Stop iterating after this many elements. Iterables can be infinite. |
- const int MAX_COUNT = 100; |
- // Per entry length overhead. It's for ", " for all after the first entry, |
- // and for "(" and ")" for the initial entry. By pure luck, that's the same |
- // number. |
- const int OVERHEAD = 2; |
- const int ELLIPSIS_SIZE = 3; // "...".length. |
- int length = 0; |
- int count = 0; |
- Iterator it = iterable.iterator; |
- // Initial run of elements, at least HEAD_COUNT, and then continue until |
- // passing at most LENGTH_LIMIT characters. |
- while (length < LENGTH_LIMIT || count < HEAD_COUNT) { |
- if (!it.moveNext()) { |
- return; |
- } |
- String next = "${it.current}"; |
- parts.add(next); |
- length += next.length + OVERHEAD; |
- count++; |
- } |
- |
- String penultimateString; |
- String ultimateString; |
- |
- // Find last two elements. One or more of them may already be in the |
- // parts array. Include their length in `length`. |
- var penultimate = null; |
- var ultimate = null; |
- if (!it.moveNext()) { |
- if (count <= HEAD_COUNT + TAIL_COUNT) return; |
- ultimateString = parts.removeLast(); |
- penultimateString = parts.removeLast(); |
- } else { |
- penultimate = it.current; |
- count++; |
+ /** A set used to identify cyclic lists during toString() calls. */ |
+ static Set _toStringVisiting = new HashSet.identity(); |
+ |
+ /** |
+ * Convert elments of [iterable] to strings and store them in [parts]. |
+ */ |
+ static void _iterablePartsToStrings(Iterable iterable, List parts) { |
+ /* |
+ * This is the complicated part of [iterableToShortString]. |
+ * It is extracted as a separate function to avoid having too much code |
+ * inside the try/finally. |
+ */ |
+ /// Try to stay below this many characters. |
+ const int LENGTH_LIMIT = 80; |
+ /// Always at least this many elements at the start. |
+ const int HEAD_COUNT = 3; |
+ /// Always at least this many elements at the end. |
+ const int TAIL_COUNT = 2; |
+ /// Stop iterating after this many elements. Iterables can be infinite. |
+ const int MAX_COUNT = 100; |
+ // Per entry length overhead. It's for ", " for all after the first entry, |
+ // and for "(" and ")" for the initial entry. By pure luck, that's the same |
+ // number. |
+ const int OVERHEAD = 2; |
+ const int ELLIPSIS_SIZE = 3; // "...".length. |
+ |
+ int length = 0; |
+ int count = 0; |
+ Iterator it = iterable.iterator; |
+ // Initial run of elements, at least HEAD_COUNT, and then continue until |
+ // passing at most LENGTH_LIMIT characters. |
+ while (length < LENGTH_LIMIT || count < HEAD_COUNT) { |
+ if (!it.moveNext()) return; |
+ String next = "${it.current}"; |
+ parts.add(next); |
+ length += next.length + OVERHEAD; |
+ count++; |
+ } |
+ |
+ String penultimateString; |
+ String ultimateString; |
+ |
+ // Find last two elements. One or more of them may already be in the |
+ // parts array. Include their length in `length`. |
+ var penultimate = null; |
+ var ultimate = null; |
if (!it.moveNext()) { |
- if (count <= HEAD_COUNT + 1) { |
- parts.add("$penultimate"); |
- return; |
- } |
- ultimateString = "$penultimate"; |
+ if (count <= HEAD_COUNT + TAIL_COUNT) return; |
+ ultimateString = parts.removeLast(); |
penultimateString = parts.removeLast(); |
- length += ultimateString.length + OVERHEAD; |
} else { |
- ultimate = it.current; |
+ penultimate = it.current; |
count++; |
- // Then keep looping, keeping the last two elements in variables. |
- assert(count < MAX_COUNT); |
- while (it.moveNext()) { |
- penultimate = ultimate; |
+ if (!it.moveNext()) { |
+ if (count <= HEAD_COUNT + 1) { |
+ parts.add("$penultimate"); |
+ return; |
+ } |
+ ultimateString = "$penultimate"; |
+ penultimateString = parts.removeLast(); |
+ length += ultimateString.length + OVERHEAD; |
+ } else { |
ultimate = it.current; |
count++; |
- if (count > MAX_COUNT) { |
- // If we haven't found the end before MAX_COUNT, give up. |
- // This cannot happen in the code above because each entry |
- // increases length by at least two, so there is no way to |
- // visit more than ~40 elements before this loop. |
- |
- // Remove any surplus elements until length, including ", ...)", |
- // is at most LENGTH_LIMIT. |
- while (length > LENGTH_LIMIT - ELLIPSIS_SIZE - OVERHEAD && |
- count > HEAD_COUNT) { |
- length -= parts.removeLast().length + OVERHEAD; |
- count--; |
+ // Then keep looping, keeping the last two elements in variables. |
+ assert(count < MAX_COUNT); |
+ while (it.moveNext()) { |
+ penultimate = ultimate; |
+ ultimate = it.current; |
+ count++; |
+ if (count > MAX_COUNT) { |
+ // If we haven't found the end before MAX_COUNT, give up. |
+ // This cannot happen in the code above because each entry |
+ // increases length by at least two, so there is no way to |
+ // visit more than ~40 elements before this loop. |
+ |
+ // Remove any surplus elements until length, including ", ...)", |
+ // is at most LENGTH_LIMIT. |
+ while (length > LENGTH_LIMIT - ELLIPSIS_SIZE - OVERHEAD && |
+ count > HEAD_COUNT) { |
+ length -= parts.removeLast().length + OVERHEAD; |
+ count--; |
+ } |
+ parts.add("..."); |
+ return; |
} |
- parts.add("..."); |
- return; |
} |
+ penultimateString = "$penultimate"; |
+ ultimateString = "$ultimate"; |
+ length += |
+ ultimateString.length + penultimateString.length + 2 * OVERHEAD; |
} |
- penultimateString = "$penultimate"; |
- ultimateString = "$ultimate"; |
- length += |
- ultimateString.length + penultimateString.length + 2 * OVERHEAD; |
} |
- } |
- |
- // If there is a gap between the initial run and the last two, |
- // prepare to add an ellipsis. |
- String elision = null; |
- if (count > parts.length + TAIL_COUNT) { |
- elision = "..."; |
- length += ELLIPSIS_SIZE + OVERHEAD; |
- } |
- // If the last two elements were very long, and we have more than |
- // HEAD_COUNT elements in the initial run, drop some to make room for |
- // the last two. |
- while (length > LENGTH_LIMIT && parts.length > HEAD_COUNT) { |
- String lastPart = parts.removeLast(); |
- length -= lastPart.length + OVERHEAD; |
- if (elision == null) { |
+ // If there is a gap between the initial run and the last two, |
+ // prepare to add an ellipsis. |
+ String elision = null; |
+ if (count > parts.length + TAIL_COUNT) { |
elision = "..."; |
length += ELLIPSIS_SIZE + OVERHEAD; |
} |
+ |
+ // If the last two elements were very long, and we have more than |
+ // HEAD_COUNT elements in the initial run, drop some to make room for |
+ // the last two. |
+ while (length > LENGTH_LIMIT && parts.length > HEAD_COUNT) { |
+ length -= parts.removeLast().length + OVERHEAD; |
+ if (elision == null) { |
+ elision = "..."; |
+ length += ELLIPSIS_SIZE + OVERHEAD; |
+ } |
+ } |
+ if (elision != null) { |
+ parts.add(elision); |
+ } |
+ parts.add(penultimateString); |
+ parts.add(ultimateString); |
} |
- if (elision != null) { |
- parts.add(elision); |
- } |
- parts.add(penultimateString); |
- parts.add(ultimateString); |
} |