diff options
| -rw-r--r-- | src/compiler/scala/tools/nsc/matching/PatternMatchers.scala | 4 | ||||
| -rw-r--r-- | test/files/pos/sudoku.scala | 41 |
2 files changed, 43 insertions, 2 deletions
diff --git a/src/compiler/scala/tools/nsc/matching/PatternMatchers.scala b/src/compiler/scala/tools/nsc/matching/PatternMatchers.scala index 6a4f6b8a69..677c850a92 100644 --- a/src/compiler/scala/tools/nsc/matching/PatternMatchers.scala +++ b/src/compiler/scala/tools/nsc/matching/PatternMatchers.scala @@ -232,9 +232,9 @@ trait PatternMatchers { self: transform.ExplicitOuter with PatternNodes with Par object resetTrav extends Traverser { override def traverse(x:Tree): unit = x match { case vd @ ValDef(_,_,_,_)=> - if(vd.symbol.hasFlag(symtab.Flags.TRANS_FLAG)) { + if(vd.symbol.hasFlag(symtab.Flags.SYNTHETIC)) { vd.symbol.resetFlag(symtab.Flags.TRANS_FLAG) - //vd.symbol.resetFlag(symtab.Flags.MUTABLE) + vd.symbol.resetFlag(symtab.Flags.MUTABLE) } case _ => super.traverse(x) diff --git a/test/files/pos/sudoku.scala b/test/files/pos/sudoku.scala new file mode 100644 index 0000000000..b9348a8001 --- /dev/null +++ b/test/files/pos/sudoku.scala @@ -0,0 +1,41 @@ +object SudokuSolver extends Application { + // The board is represented by an array of strings (arrays of chars), + // held in a global variable m. The program begins by reading 9 lines + // of input to fill the board + var m: Array[Array[char]] = List.tabulate( 9, (x:int) => Console.readLine.toArray).toArray; + + // For printing m, a method print is defined + def print = {Console.println(""); m map (carr=>Console.println(new String(carr)))} + + // The test for validity is performed by looping over i=0..8 and + // testing the row, column and 3x3 square containing the given + // coordinate + def invalid(i:int, x:int, y:int, n:char): boolean = + i<9 && (m(y)(i) == n || m(i)(x) == n || + m(y/3*3 + i/3)(x/3*3 + i % 3) == n || invalid(i+1, x, y, n)) + + // Looping over a half-closed range of consecutive integers [l..u) + // is factored out into a higher-order function + def fold(f: (int,int)=>int, accu:int, l:int, u:int):int = + if(l==u) accu else fold(f, f(accu, l), l+1, u) + + // The search function examines each position on the board in turn, + // trying the numbers 1..9 in each unfilled position + // The function is itself a higher-order fold, accumulating the value + // accu by applying the given function f to it whenever a solution m + // is found + def search(x:int, y:int, f:(int)=>int, accu:int):int = Pair(x, y) match { + case Pair(9, y) => search(0, y+1, f, accu) // next row + case Pair(0, 9) => f(accu) // found a solution + case Pair(x, y) => if(m(y)(x) != '0') search(x+1, y, f, accu) else + fold((accu:int, n:int) => + if(invalid(0, x, y, (n + 48).toChar)) accu else { + m(y)(x) = (n + 48).toChar; + val newaccu = search(x+1, y, f, accu); + m(y)(x) = '0'; + newaccu}, accu, 1, 10)} + + // The main part of the program uses the search function to accumulate + // the total number of solutions + Console.println("\n"+search(0,0,i => {print; i+1},0)+" solution(s)") +} |