Add resetStates function for stateful rnns

src/Layer.js

@@ -71,4 +71,11 @@ export default class Layer {
     this.output = x
     return this.output
   }
+
+  /**
+   * Reset presistent state in the mode. Only applies with stateful rnns.
+   */
+  resetStates() {
+    return
+  }
 }

src/Model.js

@@ -615,6 +615,15 @@ export default class Model {
     return layer.call(x)
   }
 
+  /**
+   * Reset presistent state in the mode. Only applies with stateful rnns.
+   */
+  resetStates() {
+    this.modelLayersMap.forEach(layer => {
+      layer.resetStates()
+    })
+  }
+
   /**
    * Cleanup - important for memory management
    */

src/layers/recurrent/GRU.js

@@ -525,4 +525,8 @@ export default class GRU extends Layer {
       this.output.transferFromGLTexture()
     }
   }
+
+  resetStates() {
+    this.currentHiddenState = null
+  }
 }

src/layers/recurrent/LSTM.js

@@ -634,4 +634,9 @@ export default class LSTM extends Layer {
       this.output.transferFromGLTexture()
     }
   }
+
+  resetStates() {
+    this.previousCandidate = null
+    this.currentHiddenState = null
+  }
 }

src/layers/recurrent/SimpleRNN.js

@@ -295,4 +295,8 @@ export default class SimpleRNN extends Layer {
       this.output.transferFromGLTexture()
     }
   }
+
+  resetStates() {
+    this.currentHiddenState = null
+  }
 }