A1Partial fromVector

CHANGELOG.md

@@ -1,3 +1,8 @@
+## 1.0.6
+
+- Enhanced A1Partial to accept a vector
+- Moved the int to A1 Letters into an extension on int
+
 ## 1.0.5
 
 - Added testing is an A1 is in an A1Range with contains method

lib/src/a1.dart

@@ -91,22 +91,10 @@ class A1 implements Comparable<A1> {
   /// a1 = A1.fromVector(1,-1); // FormatException
   /// ```
   A1.fromVector(int column, int row) {
-    if (column < 0 || row < 0) {
-      throw FormatException('column & row must be positive ($column,$row)');
+    if (row.isNegative) {
+      throw FormatException('row $row must be positive');
     }
-
-    final codeUnits = <int>[];
-    if (column < 26) {
-      codeUnits.add(65 + column);
-    } else {
-      var evaluationIndex = column;
-      while (evaluationIndex >= 26) {
-        codeUnits.add(65 + evaluationIndex % 26);
-        evaluationIndex = (evaluationIndex / 26 - 1).floor();
-      }
-      codeUnits.add(65 + evaluationIndex);
-    }
-    letters = String.fromCharCodes(codeUnits.reversed);
+    letters = column.a1Letters;
     digits = row + 1;
   }
 
@@ -227,6 +215,27 @@ class A1 implements Comparable<A1> {
 extension A1Tools on int {
   bool get isA1Letter => this >= 'A'.codeUnitAt(0) && this <= 'Z'.codeUnitAt(0);
   bool get isA1Digit => this >= '0'.codeUnitAt(0) && this <= '9'.codeUnitAt(0);
+
+  /// Return the letters for an [A1] from this int or throw
+  /// a [FormatException].
+  String get a1Letters {
+    if (isNegative) {
+      throw FormatException('column $this must be positive');
+    }
+
+    final codeUnits = <int>[];
+    if (this < 26) {
+      codeUnits.add(65 + this);
+    } else {
+      var evaluationIndex = this;
+      while (evaluationIndex >= 26) {
+        codeUnits.add(65 + evaluationIndex % 26);
+        evaluationIndex = (evaluationIndex / 26 - 1).floor();
+      }
+      codeUnits.add(65 + evaluationIndex);
+    }
+    return String.fromCharCodes(codeUnits.reversed);
+  }
 }
 
 /// This extension allows an [A1] to be create from a [String]

lib/src/a1_partial.dart

@@ -16,12 +16,24 @@ class A1Partial implements Comparable {
   /// Examples:
   /// ```dart
   /// A1Partial a1p = A1Partial('A', 1); //A1
-  /// a1p = A1Partial('b'); // B <all rows>
-  /// a1p = A1Partial('1'); // 1 <all columns>
-  /// a1p = A1Partial('');  // <all columns & rows>
+  /// a1p = A1Partial('b', null); // B <all rows>
+  /// a1p = A1Partial(null, '1'); // 1 <all columns>
+  /// a1p = A1Partial(null, null);  // <all columns & rows>
   /// ```
   A1Partial(String? letters, this.digits) : letters = letters?.toUpperCase();
 
+  /// Create a A1Partial from the partial vector
+  ///
+  /// Examples:
+  /// ```dart
+  /// A1Partial a1p = A1Partial.fromVector(0, 0); //A1
+  /// a1p = A1Partial.fromVector(1, null); // B <all rows>
+  /// a1p = A1Partial.fromVector(null, 1); // 1 <all columns>
+  /// a1p = A1Partial.fromVector(null, null);  // <all columns & rows>
+  /// ```
+  factory A1Partial.fromVector(int? column, int? row) =>
+      A1Partial(column?.a1Letters, row != null ? row + 1 : null);
+
   /// If this partial has letters and digitis it get be returned as A1
   /// otherwise a null is returned
   ///

pubspec.yaml

@@ -1,5 +1,5 @@
 name: a1
-version: 1.0.5
+version: 1.0.6
 
 homepage: https://pub.dev/packages/a1
 repository: https://github.com/sjhorn/a1

test/a1_partial_test.dart

@@ -7,6 +7,10 @@ void main() {
     final a1p2 = A1Partial('B', null);
     final a1p3 = A1Partial(null, 1);
     final a1p4 = A1Partial(null, null);
+    final a1p5 = A1Partial.fromVector(1, 0);
+    test('vector matches parse', () {
+      expect(a1p1 == a1p5, isTrue);
+    });
     test('compare A1 with A1,A,1,null', () {
       expect(a1p1.compareTo(a1p1), equals(0));
       expect(a1p1.compareTo(a1p2), equals(0));

test/a1_test.dart

@@ -33,6 +33,7 @@ void main() {
       expect(a1.column, equals(25));
       expect(a1.row, equals(2));
       expect(a1.toString(), equals('Z3'));
+      expect(() => A1.fromVector(1, -1), throwsA(isA<FormatException>()));
     });
 
     test('throws from an invalid vector', () {