Default batch size to 1 + sanity check value

Improve common JSON error messge wording

src/generators.cpp

@@ -71,6 +71,10 @@ Generator::Generator(const Model& model, const GeneratorParams& params) : model_
     throw std::runtime_error("search max_length is 0");
   if (params.search.max_length > model.config_->model.context_length)
     throw std::runtime_error("max_length cannot be greater than model context_length");
+  if (params.batch_size < 1)
+    throw std::runtime_error("batch_size must be 1 or greater");
+  if (params.vocab_size < 1)
+    throw std::runtime_error("vocab_size must be 1 or greater");
 
   search_ = CreateSearch(params);
   state_ = model.CreateState(search_->GetSequenceLengths(), params);

src/generators.h

@@ -56,7 +56,7 @@ struct GeneratorParams {
   int vocab_size{};
   int context_length{};
 
-  int batch_size{};
+  int batch_size{1};
   int sequence_length{};
   int BatchBeamSize() const { return search.num_beams * batch_size; }
 

src/json.cpp

@@ -49,7 +49,7 @@ JSON::JSON(Element& element, std::string_view document) : begin_{document.data()
     int line = 1;
     const auto* last_cr = begin_;
     for (const auto* p = begin_; p < current_; p++) {
-      if (*p == '\r') {
+      if (*p == '\n') {
         line++;
         last_cr = p;
       }
@@ -108,7 +108,7 @@ void JSON::Parse_Object(Element& element) {
 
   while (true) {
     if (!Skip('\"')) {
-      throw std::runtime_error("Expecting \"");
+      throw std::runtime_error("Expecting \" to start next object name, possibly due to an extra trailing ',' before this");
     }
 
     auto name = Parse_String();

src/python/python.cpp

@@ -3,6 +3,7 @@
 #include <pybind11/numpy.h>
 #include <iostream>
 #include "../generators.h"
+#include "../json.h"
 #include "../search.h"
 #include "../models/model.h"
 
@@ -92,8 +93,8 @@ struct PyGeneratorParams : GeneratorParams {
         } else if (pybind11::isinstance<pybind11::int_>(entry.second)) {
           SetSearchNumber(search, name, entry.second.cast<int>());
         } else
-          throw std::runtime_error("Unknown search option type, can be float/bool/int");
-      } catch (const std::exception& e) {
+          throw std::runtime_error("Unknown search option type, can be float/bool/int:" + name);
+      } catch (JSON::unknown_value_error& e) {
         throw std::runtime_error("Unknown search option:" + name);
       }
     }