add an optional truncation operator when exporting (#425)

Summary:
Pull Request resolved: #425

This diff adds an optional truncation operator for bi-transformer models if configured by user.

Differential Revision: D14648704

fbshipit-source-id: 824193f02ec542c29e9668b907e313679874fb08

pytext/config/config_adapter.py

@@ -4,34 +4,41 @@
 
 
 def v0_to_v1(json_config):
-    # migrate optimizer params
+    # migrate optimizer and random_seed params
     [task] = json_config["task"].values()
     if (
         "optimizer" not in task
         or "Adam" in task["optimizer"]
         or "SGD" in task["optimizer"]
         or "NAG" in task["optimizer"]
-    ):
+    ) and ("trainer" not in task or "random_seed" not in task["trainer"]):
         return json_config
-    op_type = task["optimizer"].get("type", "adam")
-    if op_type == "adam":
-        op_config = {"Adam": {}}
-        for key in ["lr", "weight_decay"]:
-            if key in task["optimizer"]:
-                op_config["Adam"][key] = task["optimizer"][key]
-    elif op_type == "sgd":
-        op_config = {"SGD": {}}
-        for key in ["lr", "momentum"]:
-            if key in task["optimizer"]:
-                op_config["SGD"][key] = task["optimizer"][key]
-    elif op_type == "nag":
-        op_config = {"NAG": {}}
-        for key in ["lr", "weight_decay", "momentum"]:
-            if key in task["optimizer"]:
-                op_config["NAG"][key] = task["optimizer"][key]
-    else:
-        raise ValueError("Migration not supported for your optimizer")
-    task["optimizer"] = op_config
+
+    if "trainer" in task and "random_seed" in task["trainer"]:
+        json_config["random_seed"] = task["trainer"]["random_seed"]
+        del task["trainer"]["random_seed"]
+    if "optimizer" in task and not any(
+        opt in task["optimizer"] for opt in ["Adam", "SGD", "NAG"]
+    ):
+        op_type = task["optimizer"].get("type", "adam")
+        if op_type == "adam":
+            op_config = {"Adam": {}}
+            for key in ["lr", "weight_decay"]:
+                if key in task["optimizer"]:
+                    op_config["Adam"][key] = task["optimizer"][key]
+        elif op_type == "sgd":
+            op_config = {"SGD": {}}
+            for key in ["lr", "momentum"]:
+                if key in task["optimizer"]:
+                    op_config["SGD"][key] = task["optimizer"][key]
+        elif op_type == "nag":
+            op_config = {"NAG": {}}
+            for key in ["lr", "weight_decay", "momentum"]:
+                if key in task["optimizer"]:
+                    op_config["NAG"][key] = task["optimizer"][key]
+        else:
+            raise ValueError("Migration not supported for your optimizer")
+        task["optimizer"] = op_config
     json_config["version"] = 1
     return json_config