From 3ef54ec349ac7a847df8c0b2de02c2bd2cf3155f Mon Sep 17 00:00:00 2001
From: Jonathan Shimwell <mail@jshimwell.com>
Date: Wed, 14 Aug 2024 05:43:44 +0100
Subject: [PATCH] Replacing endf c functions with package (#3101)

---
 openmc/data/_endf.pyx |  8 ------
 openmc/data/endf.c    | 57 -------------------------------------------
 openmc/data/endf.py   | 10 +-------
 pyproject.toml        |  1 +
 setup.py              |  2 +-
 5 files changed, 3 insertions(+), 75 deletions(-)
 delete mode 100644 openmc/data/_endf.pyx
 delete mode 100644 openmc/data/endf.c

diff --git a/openmc/data/_endf.pyx b/openmc/data/_endf.pyx
deleted file mode 100644
index 991ee015b..000000000
--- a/openmc/data/_endf.pyx
+++ /dev/null
@@ -1,8 +0,0 @@
-# cython: c_string_type=str, c_string_encoding=ascii
-
-cdef extern from "endf.c":
-    double cfloat_endf(const char* buffer, int n)
-
-def float_endf(s):
-    cdef const char* c_string = s
-    return cfloat_endf(c_string, len(s))
diff --git a/openmc/data/endf.c b/openmc/data/endf.c
deleted file mode 100644
index dd5eee541..000000000
--- a/openmc/data/endf.c
+++ /dev/null
@@ -1,57 +0,0 @@
-#include <stdlib.h>
-
-//! Convert string representation of a floating point number into a double
-//
-//! This function handles converting floating point numbers from an ENDF 11
-//! character field into a double, covering all the corner cases. Floating point
-//! numbers are allowed to contain whitespace (which is ignored). Also, in
-//! exponential notation, it allows the 'e' to be omitted. A field containing
-//! only whitespace is to be interpreted as a zero.
-//
-//! \param buffer character input from an ENDF file
-//! \param n Length of character input
-//! \return Floating point number
-
-double cfloat_endf(const char* buffer, int n)
-{
-  char arr[13]; // 11 characters plus e and a null terminator
-  int j = 0; // current position in arr
-  int found_significand = 0;
-  int found_exponent = 0;
-
-  // limit n to 11 characters
-  n = n > 11 ? 11 : n;
-
-  int i;
-  for (i = 0; i < n; ++i) {
-    char c = buffer[i];
-
-    // Skip whitespace characters
-    if (c == ' ') continue;
-
-    if (found_significand) {
-      if (!found_exponent) {
-        if (c == '+' || c == '-') {
-          // In the case that we encounter +/- and we haven't yet encountered
-          // e/E, we manually add it
-          arr[j++] = 'e';
-          found_exponent = 1;
-
-        } else if (c == 'e' || c == 'E' || c == 'd' || c == 'D') {
-          arr[j++] = 'e';
-          found_exponent = 1;
-          continue;
-        }
-      }
-    } else if (c == '.' || (c >= '0' && c <= '9')) {
-      found_significand = 1;
-    }
-
-    // Copy character
-    arr[j++] = c;
-  }
-
-  // Done copying. Add null terminator and convert to double
-  arr[j] = '\0';
-  return atof(arr);
-}
diff --git a/openmc/data/endf.py b/openmc/data/endf.py
index 73299723a..63cd092eb 100644
--- a/openmc/data/endf.py
+++ b/openmc/data/endf.py
@@ -14,11 +14,7 @@ import numpy as np
 
 from .data import gnds_name
 from .function import Tabulated1D
-try:
-    from ._endf import float_endf
-    _CYTHON = True
-except ImportError:
-    _CYTHON = False
+from endf.records import float_endf
 
 
 _LIBRARY = {0: 'ENDF/B', 1: 'ENDF/A', 2: 'JEFF', 3: 'EFF',
@@ -91,10 +87,6 @@ def py_float_endf(s):
     return float(ENDF_FLOAT_RE.sub(r'\1e\2\3', s))
 
 
-if not _CYTHON:
-    float_endf = py_float_endf
-
-
 def int_endf(s):
     """Convert string of integer number in ENDF to int.
 
diff --git a/pyproject.toml b/pyproject.toml
index 2b2764cea..98b1d152f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -34,6 +34,7 @@ dependencies = [
     "lxml",
     "uncertainties",
     "setuptools",
+    "endf",
 ]
 
 [project.optional-dependencies]
diff --git a/setup.py b/setup.py
index 4e24f48a1..88a45a360 100755
--- a/setup.py
+++ b/setup.py
@@ -6,7 +6,7 @@ from Cython.Build import cythonize
 
 
 kwargs = {
-    # Cython is used to add resonance reconstruction and fast float_endf
+    # Cython is used to add resonance reconstruction
     'ext_modules': cythonize('openmc/data/*.pyx'),
     'include_dirs': [np.get_include()]
 }