array_to_nix refactoring step 2

Author: asobolev

src/utils/arguments.h

@@ -62,20 +62,21 @@ class extractor : public argument_helper<const mxArray> {
     extractor(const mxArray **arr, int n) : argument_helper(arr, n) { }
 
     std::string str(size_t pos) const {
-		check_arg_type(pos, nix::DataType::String);
-
-        char *tmp = mxArrayToString(array[pos]);
-        std::string the_string(tmp);
-        mxFree(tmp);
-        return the_string;
+        return mx_array_to_str(array[pos]);
     }
 
     template<typename T>
     T num(size_t pos) const {
-        nix::DataType dtype = nix::to_data_type<T>::value;
-        check_arg_type(pos, dtype);
+        check_arg_type(pos, nix::to_data_type<T>::value);
+
+        if (mxGetNumberOfElements(array[pos]) < 1) {
+            throw std::runtime_error("array empty");
+        }
 
-        return mx_array_to_num<T>(array[pos]);
+        const void *data = mxGetData(array[pos]);
+        T res;
+        memcpy(&res, data, sizeof(T));
+        return res;
     }
 
     template<typename T>

src/utils/nix2mx.cc

@@ -12,6 +12,12 @@
 #include "datatypes.h"
 
 
+void check_arg_type(const mxArray *arr, nix::DataType dtype) {
+    if (dtype_mex2nix(arr) != dtype) {
+        throw std::invalid_argument("wrong type");
+    }
+}
+
 mxArray *nmCreateScalar(uint32_t val) {
     mxArray *arr = mxCreateNumericMatrix(1, 1, mxUINT32_CLASS, mxREAL);
     void *data = mxGetData(arr);
@@ -73,13 +79,18 @@ nix::NDSize mx_array_to_ndsize(const mxArray *arr) {
     return size;
 }
 
+std::string mx_array_to_str(const mxArray *arr) {
+    check_arg_type(arr, nix::DataType::String);
+
+    char *tmp = mxArrayToString(arr);
+    std::string the_string(tmp);
+    mxFree(tmp);
+    return the_string;
+}
+
 template<typename T>
 T mx_array_to_num(const mxArray *arr) {
-    nix::DataType dtype = nix::to_data_type<T>::value;
-    
-    if (dtype_mex2nix(arr) != dtype) {
-        throw std::invalid_argument("wrong type");
-    }
+    check_arg_type(arr, nix::to_data_type<T>::value);
 
     if (mxGetNumberOfElements(arr) < 1) {
         throw std::runtime_error("array empty");
@@ -91,26 +102,31 @@ T mx_array_to_num(const mxArray *arr) {
     return res;
 }
 
+bool mx_array_to_bool(const mxArray *arr) {
+    check_arg_type(arr, nix::DataType::Bool);
+
+    const mxLogical *l = mxGetLogicals(arr);
+    return l[0];
+}
+
 nix::Value mx_array_to_value(const mxArray *arr) {
     nix::Value val;
 
     switch (mxGetClassID(arr)) {
-    case mxLOGICAL_CLASS: val.set(mx_array_to_num<bool>(arr)); break;
-
-    case mxCHAR_CLASS: val.set(mx_array_to_num<std::string>(arr)); break;
-
+    case mxLOGICAL_CLASS: val.set(mx_array_to_bool(arr)); break;
+    case mxCHAR_CLASS: val.set(mx_array_to_str(arr)); break;
     case mxDOUBLE_CLASS: val.set(mx_array_to_num<double>(arr)); break;
-    case mxSINGLE_CLASS: val.set(mx_array_to_num<float>(arr)); break;
-
-    case mxUINT8_CLASS:  val.set(mx_array_to_num<uint8_t>(arr)); break;
-    case mxINT8_CLASS:   val.set(mx_array_to_num<int8_t>(arr)); break;
-    case mxUINT16_CLASS: val.set(mx_array_to_num<uint16_t>(arr)); break;
-    case mxINT16_CLASS:  val.set(mx_array_to_num<int16_t>(arr)); break;
     case mxUINT32_CLASS: val.set(mx_array_to_num<uint32_t>(arr)); break;
     case mxINT32_CLASS:  val.set(mx_array_to_num<int32_t>(arr)); break;
     case mxUINT64_CLASS: val.set(mx_array_to_num<uint64_t>(arr)); break;
     case mxINT64_CLASS:  val.set(mx_array_to_num<int64_t>(arr)); break;
 
+    case mxSINGLE_CLASS: throw std::invalid_argument("Element type is not supported");
+    case mxUINT8_CLASS:  throw std::invalid_argument("Element type is not supported");
+    case mxINT8_CLASS:   throw std::invalid_argument("Element type is not supported");
+    case mxUINT16_CLASS: throw std::invalid_argument("Element type is not supported");
+    case mxINT16_CLASS:  throw std::invalid_argument("Element type is not supported");
+
     default: throw std::invalid_argument("Element type is not recognized");
     }
 

src/utils/nix2mx.h

@@ -5,11 +5,17 @@
 #include <nix.hpp>
 #include "datatypes.h"
 
+void check_arg_type(const mxArray *arr, nix::DataType dtype);
+
 nix::NDSize mx_array_to_ndsize(const mxArray *arr);
 
+std::string mx_array_to_str(const mxArray *arr);
+
 template<typename T>
 T mx_array_to_num(const mxArray *arr);
 
+bool mx_array_to_bool(const mxArray *arr);
+
 nix::Value mx_array_to_value(const mxArray *arr);
 
 mxArray *nmCreateScalar(uint32_t val);