fix

fast_llm/data/dataset/gpt/config.py

@@ -22,7 +22,7 @@
     from fast_llm.data.data.gpt.data import GPTData
     from fast_llm.data.dataset.gpt.abstract import GPTIndexedDataset
     from fast_llm.data.dataset.gpt.concatenated import GPTConcatenatedDataset
-    from fast_llm.data.dataset.gpt.dummy import GPTDummyDataset
+    from fast_llm.data.dataset.gpt.dummy import GPTDummySampledDataset
     from fast_llm.data.dataset.gpt.memmap import GPTMemmapDataset
 
 
@@ -102,15 +102,32 @@ def build(self, data: "GPTData") -> "GPTIndexedDataset":
 
 
 @config_class()
-class GPTDummyDatasetConfig(GPTSamplableDatasetConfig, type_="dummy"):
+class GPTDummyDatasetConfig(GPTSampledSplitDatasetConfig, type_="dummy"):
+    # NA -> (unsampled, unsplit)
+    _abstract = False
     name: str = Field(
         default="dummy",
         desc="The name of the dataset.",
         hint=FieldHint.core,
     )
 
-    def build(self, data: "GPTData") -> "GPTDummyDataset":
-        return GPTDummyDataset(self.name, data.max_sequence_length, data.vocab_size)
+    def build_split_sample(
+        self,
+        data: "GPTData",
+        config: PhaseSplits[GPTSamplingConfig],
+        default_phase: PhaseType = PhaseType.training,
+    ) -> "SampledSplitDataset[GPTDummySampledDataset]":
+        from fast_llm.data.dataset.gpt.dummy import GPTDummyDataset, GPTDummySampledDataset
+
+        return SampledSplitDataset[GPTDummySampledDataset](
+            self.name,
+            {
+                phase: GPTDummyDataset(f"{self.name}_{phase.value}", data.max_sequence_length, data.vocab_size).sample(
+                    phase_config, data
+                )
+                for phase, phase_config in config.items()
+            },
+        )
 
 
 @config_class()
@@ -191,7 +208,7 @@ def build_split(
 @config_class()
 class GPTBlendedDatasetConfig(BlendedDatasetConfig, GPTSampledDatasetConfig, type_="blended"):
     _abstract = False
-    datasets: list[GPTSampledDatasetConfig] = FieldUpdate(desc="UINGBRI")
+    datasets: list[GPTSampledDatasetConfig] = FieldUpdate()
 
 
 class LegacyDatasetSource(str, enum.Enum):