Re-arrange source code and tests

Sources/SwiftUIMath/Internal/Syntax/Atoms/Table.swift

@@ -0,0 +1,101 @@
+import Foundation
+
+extension Math {
+  final class Table: Atom {
+    enum ColumnAlignment {
+      case left
+      case center
+      case right
+    }
+
+    var alignments: [ColumnAlignment]
+    var cells: [[AtomList]]
+    var environment: String
+    var interColumnSpacing: CGFloat
+    var interRowAdditionalSpacing: CGFloat
+
+    override var finalized: Math.Atom {
+      let finalized = super.finalized
+
+      if let table = finalized as? Table {
+        table.cells = table.cells.map { row in
+          row.map { $0.finalized }
+        }
+      }
+
+      return finalized
+    }
+
+    init(_ table: Table) {
+      self.alignments = table.alignments
+      self.cells = table.cells.map { row in
+        row.map { AtomList($0) }
+      }
+      self.environment = table.environment
+      self.interColumnSpacing = table.interColumnSpacing
+      self.interRowAdditionalSpacing = table.interRowAdditionalSpacing
+
+      super.init(table)
+    }
+
+    init(
+      alignments: [ColumnAlignment] = [],
+      cells: [[AtomList]] = [],
+      environment: String = "",
+      interColumnSpacing: CGFloat = 0,
+      interRowAdditionalSpacing: CGFloat = 0
+    ) {
+      self.alignments = alignments
+      self.cells = cells
+      self.environment = environment
+      self.interColumnSpacing = interColumnSpacing
+      self.interRowAdditionalSpacing = interRowAdditionalSpacing
+      super.init(type: .table)
+    }
+
+    func setCell(_ cell: AtomList, forRow row: Int, column: Int) {
+      if cells.count <= row {
+        for _ in cells.count...row {
+          cells.append([])
+        }
+      }
+
+      if cells[row].count <= column {
+        for _ in cells[row].count...column {
+          cells[row].append(AtomList())
+        }
+      }
+
+      cells[row][column] = cell
+    }
+
+    func setAlignment(_ alignment: ColumnAlignment, forColumn column: Int) {
+      if alignments.count <= column {
+        for _ in alignments.count...column {
+          alignments.append(.center)
+        }
+      }
+
+      alignments[column] = alignment
+    }
+
+    func alignment(forColumn column: Int) -> ColumnAlignment {
+      if alignments.count <= column {
+        return .center
+      }
+      return alignments[column]
+    }
+
+    var numberOfColumns: Int {
+      var count = 0
+      for row in cells {
+        count = max(count, row.count)
+      }
+      return count
+    }
+
+    var numberOfRows: Int {
+      cells.count
+    }
+  }
+}