IParser: Use long long int

* Use long long int as the underlying integer data type in IParser.

* Extend number format to include `3e9`, `2.34e6`, `1'000'000`, etc.

Docs/sphinx_documentation/source/Basics.rst

@@ -453,7 +453,11 @@ Besides :cpp:`amrex::Parser` for floating point numbers, AMReX also provides
 similarity, but floating point number specific functions (e.g., ``sqrt``,
 ``sin``, etc.) are not supported in ``IParser``.  In addition to ``/`` whose
 result truncates towards zero, the integer parser also supports ``//`` whose
-result truncates towards negative infinity.
+result truncates towards negative infinity. Single quotes ``'`` are allowed
+as a separator for :cpp:`IParser` numbers just like C++ integer
+literals. Additionally, a floating point like number with a positive
+exponent may be accepted as an integer if it is reasonable to do so. For
+example, it's okay to have ``1.234e3``, but ``1.23e2`` is an error.
 
 .. _sec:basics:initialize:
 

Src/Base/Parser/AMReX_IParser.H

@@ -18,24 +18,25 @@ struct IParserExecutor
 {
     template <int M=N, std::enable_if_t<M==0,int> = 0>
     [[nodiscard]] AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
-    int operator() () const noexcept
+    long long operator() () const noexcept
     {
         AMREX_IF_ON_DEVICE((return iparser_exe_eval(m_device_executor, nullptr);))
         AMREX_IF_ON_HOST((return iparser_exe_eval(m_host_executor, nullptr);))
     }
 
     template <typename... Ts>
     [[nodiscard]] AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
-    std::enable_if_t<sizeof...(Ts) == N, int>
+    std::enable_if_t<sizeof...(Ts) == N && std::conjunction_v<std::is_integral<Ts>...>,
+                     long long>
     operator() (Ts... var) const noexcept
     {
-        amrex::GpuArray<int,N> l_var{var...};
+        amrex::GpuArray<long long,N> l_var{var...};
         AMREX_IF_ON_DEVICE((return iparser_exe_eval(m_device_executor, l_var.data());))
         AMREX_IF_ON_HOST((return iparser_exe_eval(m_host_executor, l_var.data());))
     }
 
     [[nodiscard]] AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
-    int operator() (GpuArray<int,N> const& var) const noexcept
+    long long operator() (GpuArray<long long, N> const& var) const noexcept
     {
         AMREX_IF_ON_DEVICE((return iparser_exe_eval(m_device_executor, var.data());))
         AMREX_IF_ON_HOST((return iparser_exe_eval(m_host_executor, var.data());))
@@ -62,7 +63,7 @@ public:
 
     explicit operator bool () const;
 
-    void setConstant (std::string const& name, int c);
+    void setConstant (std::string const& name, long long c);
 
     void registerVariables (Vector<std::string> const& vars);
 

Src/Base/Parser/AMReX_IParser.cpp

@@ -54,7 +54,7 @@ IParser::operator bool () const
 }
 
 void
-IParser::setConstant (std::string const& name, int c)
+IParser::setConstant (std::string const& name, long long c)
 {
     if (m_data && m_data->m_iparser) {
         iparser_setconst(m_data->m_iparser, name.c_str(), c);