Files
lammps/src/utils.h

915 lines
37 KiB
C++

/* -*- c++ -*- ----------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
https://www.lammps.org/, Sandia National Laboratories
LAMMPS development team: developers@lammps.org
Copyright (2003) Sandia Corporation. Under the terms of Contract
DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
certain rights in this software. This software is distributed under
the GNU General Public License.
See the README file in the top-level LAMMPS directory.
------------------------------------------------------------------------- */
#ifndef LMP_UTILS_H
#define LMP_UTILS_H
/*! \file utils.h */
#include "fmt/format.h"
#include "lmptype.h"
#include <mpi.h>
#include <string>
#include <vector> // IWYU pragma: export
namespace LAMMPS_NS {
// forward declarations
class Error;
class Input;
class LAMMPS;
namespace utils {
/*! Match text against a simplified regex pattern
*
* \param text the text to be matched against the pattern
* \param pattern the search pattern, which may contain regexp markers
* \return true if the pattern matches, false if not */
bool strmatch(const std::string &text, const std::string &pattern);
/*! Compare two string while ignoring whitespace
*
\verbatim embed:rst
.. versionadded:: 4Feb2025
This function compares two strings while skipping over any kind of whitespace
(blank, tab, newline, carriage return, etc.).
\endverbatim
*
* \param text1 the first text to be compared
* \param text2 the second text to be compared
* \return true if the non-whitespace part of the two strings matches, false if not */
bool strsame(const std::string &text1, const std::string &text2);
/*! Compress whitespace in a string
*
\verbatim embed:rst
.. versionadded:: 4Feb2025
This function compresses whitespace in a string to just a single blank.
\endverbatim
*
* \param text the text to be compressed
* \return string with whitespace compressed to single blanks */
std::string strcompress(const std::string &text);
/*! Find sub-string that matches a simplified regex pattern
*
* \param text the text to be matched against the pattern
* \param pattern the search pattern, which may contain regexp markers
* \return the string that matches the pattern or an empty one */
std::string strfind(const std::string &text, const std::string &pattern);
/*! Print error message about missing arguments for command
*
* This function simplifies the repetitive reporting missing arguments to a command.
*
* \param file name of source file for error message
* \param line line number in source file for error message
* \param cmd name of the failing command
* \param error pointer to Error class instance (for abort) or nullptr */
void missing_cmd_args(const std::string &file, int line, const std::string &cmd, Error *error);
/*! Create string with last command and optionally pointing to arg with error
*
\verbatim embed:rst
.. versionadded:: 4Feb2025
This function is a helper function for error messages. It creates extra output
in error messages. It will produce either two or three lines: the original last
input line *before* variable substitutions, the corresponding pre-processed command
(only when different) and one or more '^' characters pointing to the faulty argument
as indicated by the *failed* argument. Any whitespace in the lines with the command
output are compressed to a single blank by calling :cpp:func:`strcompress()`
\endverbatim
*
* \param input pointer to the Input class instance (for access to last command args)
* \param failed index of the faulty argument (-1 to point to the command itself)
* \return string with two or three lines to follow error messages */
std::string point_to_error(Input *input, int failed);
/*! Internal function handling the argument list for logmesg(). */
void fmtargs_logmesg(LAMMPS *lmp, fmt::string_view format, fmt::format_args args);
/*! Send formatted message to screen and logfile, if available
*
* This function simplifies the repetitive task of outputting some
* message to both the screen and/or the log file. The template
* wrapper with {fmt} formatting and argument processing allows
* this function to work similar to :cpp:func:`utils::print() <LAMMPS_NS::utils::print>`.
*
* \param lmp pointer to LAMMPS class instance
* \param format format string of message to be printed
* \param args arguments to format string */
template <typename... Args> void logmesg(LAMMPS *lmp, const std::string &format, Args &&...args)
{
fmtargs_logmesg(lmp, format, fmt::make_format_args(args...));
}
/*! \overload
*
* \param lmp pointer to LAMMPS class instance
* \param mesg string with message to be printed */
void logmesg(LAMMPS *lmp, const std::string &mesg);
/*! Internal function handling the argument list for print(). */
void fmtargs_print(FILE *fp, fmt::string_view format, fmt::format_args args);
/*! Write formatted message to file
*
\verbatim embed:rst
.. versionadded:: 4Feb2025
\endverbatim
*
* This function implements a version of (f)printf() that uses {fmt} formatting
*
* \param fp stdio FILE pointer
* \param format format string of message to be printed
* \param args arguments to format string */
template <typename... Args> void print(FILE *fp, const std::string &format, Args &&...args)
{
fmtargs_print(fp, format, fmt::make_format_args(args...));
}
/*! \overload
*
* Print to stdout without specifying the FILE pointer.
*
* \param mesg string with message to be printed */
template <typename... Args> void print(const std::string &format, Args &&...args)
{
fmtargs_print(stdout, format, fmt::make_format_args(args...));
}
/*! \overload
*
* Print string message without format
*
* \param fp stdio FILE pointer
* \param mesg string with message to be printed */
void print(FILE *fp, const std::string &mesg);
/*! \overload
*
* Print string message without format to stdout
*
* \param mesg string with message to be printed */
void print(const std::string &mesg);
/*! Return text redirecting the user to a specific paragraph in the manual
*
* The LAMMPS manual contains detailed explanations for errors and
* warnings where a simple error message may not be sufficient. These can
* be reached through URLs with a numeric code > 0. This function creates the
* corresponding text to be included into the error message that redirects
* the user to that URL. Using an error code of 0 returns a message
* pointing to a URL discussing error messages in general.
*
* \param errorcode non-negative number pointing to a paragraph in the manual */
std::string errorurl(int errorcode);
/*! Flush output buffers
*
* This function calls fflush() on screen and logfile FILE pointers
* if available and thus tells the operating system to output all
* currently buffered data. This is local operation and independent
* from buffering by a file system or an MPI library.
*/
void flush_buffers(LAMMPS *lmp);
/*! Return a string representing the current system error status
*
* This is a wrapper around calling strerror(errno).
*
* \return error string */
std::string getsyserror();
/*! Wrapper around fgets() which reads whole lines but truncates the
* data to the buffer size and ensures a newline char at the end.
*
* This function is useful for reading line based text files with
* possible comments that should be parsed later. This applies to
* data files, potential files, atomfile variable files and so on.
* It is used instead of fgets() by utils::read_lines_from_file().
*
* \param s buffer for storing the result of fgets()
* \param size size of buffer s (max number of bytes returned)
* \param fp file pointer used by fgets() */
char *fgets_trunc(char *s, int size, FILE *fp);
/*! Safe wrapper around fgets() which aborts on errors
* or EOF and prints a suitable error message to help debugging.
*
* Use nullptr as the error parameter to avoid the abort on EOF or error.
*
* \param srcname name of the calling source file (from FLERR macro)
* \param srcline line in the calling source file (from FLERR macro)
* \param s buffer for storing the result of fgets()
* \param size size of buffer s (max number of bytes read by fgets())
* \param fp file pointer used by fgets()
* \param filename file name associated with fp (may be a null pointer; then LAMMPS will try to detect)
* \param error pointer to Error class instance (for abort) or nullptr */
void sfgets(const char *srcname, int srcline, char *s, int size, FILE *fp, const char *filename,
Error *error);
/*! Safe wrapper around fread() which aborts on errors
* or EOF and prints a suitable error message to help debugging.
*
* Use nullptr as the error parameter to avoid the abort on EOF or error.
*
* \param srcname name of the calling source file (from FLERR macro)
* \param srcline line in the calling source file (from FLERR macro)
* \param s buffer for storing the result of fread()
* \param size size of data elements read by fread()
* \param num number of data elements read by fread()
* \param fp file pointer used by fread()
* \param filename file name associated with fp (may be a null pointer; then LAMMPS will try to detect)
* \param error pointer to Error class instance (for abort) or nullptr */
void sfread(const char *srcname, int srcline, void *s, size_t size, size_t num, FILE *fp,
const char *filename, Error *error);
/*! Read N lines of text from file into buffer and broadcast them
*
* This function uses repeated calls to fread() to fill a buffer with
* newline terminated text. If a line does not end in a newline (e.g.
* at the end of a file), it is added. The caller has to allocate an
* nlines by nmax sized buffer for storing the text data.
* Reading is done by MPI rank 0 of the given communicator only, and
* thus only MPI rank 0 needs to provide a valid file pointer.
*
* \param fp file pointer used by fread
* \param nlines number of lines to be read
* \param nmax maximum length of a single line
* \param buffer buffer for storing the data.
* \param me MPI rank of calling process in MPI communicator
* \param comm MPI communicator for broadcast
* \return 1 if the read was short, 0 if read was successful */
int read_lines_from_file(FILE *fp, int nlines, int nmax, char *buffer, int me, MPI_Comm comm);
/*! Report if a requested style is in a package or may have a typo
*
* \param style type of style that is to be checked for
* \param name name of style that was not found
* \param lmp pointer to top-level LAMMPS class instance
* \return string usable for error messages */
std::string check_packages_for_style(const std::string &style, const std::string &name,
LAMMPS *lmp);
/*! Convert a string to a boolean while checking whether it is a valid boolean term.
* Valid terms are 'yes', 'no', 'true', 'false', 'on', 'off', and '1', '0'. Only
* lower case is accepted.
*
* \param file name of source file for error message
* \param line line number in source file for error message
* \param str string to be converted to logical
* \param do_abort determines whether to call Error::one() or Error::all()
* \param lmp pointer to top-level LAMMPS class instance
* \return 1 if string resolves to "true", otherwise 0 */
int logical(const char *file, int line, const std::string &str, bool do_abort, LAMMPS *lmp);
/*! \overload
*
* \param file name of source file for error message
* \param line line number in source file for error message
* \param str string to be converted to logical
* \param do_abort determines whether to call Error::one() or Error::all()
* \param lmp pointer to top-level LAMMPS class instance
* \return 1 if string resolves to "true", otherwise 0 */
int logical(const char *file, int line, const char *str, bool do_abort, LAMMPS *lmp);
/*! Convert a string to a floating point number while checking
* if it is a valid floating point or integer number
*
* \param file name of source file for error message
* \param line line number in source file for error message
* \param str string to be converted to number
* \param do_abort determines whether to call Error::one() or Error::all()
* \param lmp pointer to top-level LAMMPS class instance
* \return double precision floating point number */
double numeric(const char *file, int line, const std::string &str, bool do_abort, LAMMPS *lmp);
/*! \overload
*
* \param file name of source file for error message
* \param line line number in source file for error message
* \param str string to be converted to number
* \param do_abort determines whether to call Error::one() or Error::all()
* \param lmp pointer to top-level LAMMPS class instance
* \return double precision floating point number */
double numeric(const char *file, int line, const char *str, bool do_abort, LAMMPS *lmp);
/*! Convert a string to an integer number while checking
* if it is a valid integer number (regular int)
*
* \param file name of source file for error message
* \param line line number in source file for error message
* \param str string to be converted to number
* \param do_abort determines whether to call Error::one() or Error::all()
* \param lmp pointer to top-level LAMMPS class instance
* \return integer number (regular int) */
int inumeric(const char *file, int line, const std::string &str, bool do_abort, LAMMPS *lmp);
/*! \overload
*
* \param file name of source file for error message
* \param line line number in source file for error message
* \param str string to be converted to number
* \param do_abort determines whether to call Error::one() or Error::all()
* \param lmp pointer to top-level LAMMPS class instance
* \return double precision floating point number */
int inumeric(const char *file, int line, const char *str, bool do_abort, LAMMPS *lmp);
/*! Convert a string to an integer number while checking
* if it is a valid integer number (bigint)
*
* \param file name of source file for error message
* \param line line number in source file for error message
* \param str string to be converted to number
* \param do_abort determines whether to call Error::one() or Error::all()
* \param lmp pointer to top-level LAMMPS class instance
* \return integer number (bigint) */
bigint bnumeric(const char *file, int line, const std::string &str, bool do_abort, LAMMPS *lmp);
/*! \overload
*
* \param file name of source file for error message
* \param line line number in source file for error message
* \param str string to be converted to number
* \param do_abort determines whether to call Error::one() or Error::all()
* \param lmp pointer to top-level LAMMPS class instance
* \return double precision floating point number */
bigint bnumeric(const char *file, int line, const char *str, bool do_abort, LAMMPS *lmp);
/*! Convert a string to an integer number while checking
* if it is a valid integer number (tagint)
*
* \param file name of source file for error message
* \param line line number in source file for error message
* \param str string to be converted to number
* \param do_abort determines whether to call Error::one() or Error::all()
* \param lmp pointer to top-level LAMMPS class instance
* \return integer number (tagint) */
tagint tnumeric(const char *file, int line, const std::string &str, bool do_abort, LAMMPS *lmp);
/*! \overload
*
* \param file name of source file for error message
* \param line line number in source file for error message
* \param str string to be converted to number
* \param do_abort determines whether to call Error::one() or Error::all()
* \param lmp pointer to top-level LAMMPS class instance
* \return double precision floating point number */
tagint tnumeric(const char *file, int line, const char *str, bool do_abort, LAMMPS *lmp);
/*! Compute index bounds derived from a string with a possible wildcard
*
* This functions processes the string in *str* and set the values of *nlo*
* and *nhi* according to the following five cases:
*
* - a single number, i: nlo = i; nhi = i;
* - a single asterisk, \*: nlo = nmin; nhi = nmax;
* - a single number followed by an asterisk, i\*: nlo = i; nhi = nmax;
* - a single asterisk followed by a number, \*i: nlo = nmin; nhi = i;
* - two numbers with an asterisk in between. i\*j: nlo = i; nhi = j;
*
* \param file name of source file for error message
* \param line line number in source file for error message
* \param str string to be processed
* \param nmin smallest possible lower bound
* \param nmax largest allowed upper bound
* \param nlo lower bound
* \param nhi upper bound
* \param error pointer to Error class for out-of-bounds messages
* \param failed argument index with failed expansion (optional) */
template <typename TYPE>
void bounds(const char *file, int line, const std::string &str, bigint nmin, bigint nmax,
TYPE &nlo, TYPE &nhi, Error *error, int failed = -2); // -2 = Error::NOPOINTER
/*! Same as utils::bounds(), but string may be a typelabel
*
\verbatim embed:rst
.. versionadded:: 27June2024
This functions adds the following case to :cpp:func:`utils::bounds() <LAMMPS_NS::utils::bounds>`:
- a single type label, typestr: nlo = nhi = label2type(typestr)
\endverbatim
* \param file name of source file for error message
* \param line line number in source file for error message
* \param str string to be processed
* \param nmin smallest possible lower bound
* \param nmax largest allowed upper bound
* \param nlo lower bound
* \param nhi upper bound
* \param lmp pointer to top-level LAMMPS class instance
* \param mode select labelmap using constants from Atom class */
template <typename TYPE>
void bounds_typelabel(const char *file, int line, const std::string &str, bigint nmin,
bigint nmax, TYPE &nlo, TYPE &nhi, LAMMPS *lmp, int mode);
/*! Expand list of arguments when containing fix/compute wildcards
*
* This function searches the list of arguments in *arg* for strings
* of the kind c_ID[*], f_ID[*], v_ID[*], i2_ID[*], d2_ID[*], or
* c_ID:gname:dname[*] referring to computes, fixes, vector style
* variables, custom per-atom arrays, or grids, respectively.
* Any such strings are replaced by one or more strings with the
* '*' character replaced by the corresponding possible numbers as
* determined from the fix, compute, variable, property, or grid instance.
* Unrecognized strings are just copied. If the *mode* parameter
* is set to 0, expand global vectors, but not global arrays; if it is
* set to 1, expand global arrays (by column) but not global vectors.
*
* If any expansion happens, the earg list and all its
* strings are new allocations and must be freed explicitly by the
* caller. Otherwise arg and earg will point to the same address
* and no explicit de-allocation is needed by the caller.
*
* The *argmap* pointer to an int pointer may be used to accept an array
* of integers mapping the arguments after the expansion to their original
* index. If this pointer is NULL (the default) than this map is not created.
* Otherwise, it must be deallocated by the calling code.
*
* \param file name of source file for error message
* \param line line number in source file for error message
* \param narg number of arguments in current list
* \param arg argument list, possibly containing wildcards
* \param mode select between global vectors(=0) and arrays (=1)
* \param earg new argument list with wildcards expanded
* \param lmp pointer to top-level LAMMPS class instance
* \param argmap pointer to integer pointer for mapping expanded indices to input (optional)
* \return number of arguments in expanded list */
int expand_args(const char *file, int line, int narg, char **arg, int mode, char **&earg,
LAMMPS *lmp, int **argmap = nullptr);
/*! Expand type label string into its equivalent numeric type
*
* This function checks if a given string may be a type label and
* then searches the labelmap type indicated by the *mode* argument
* for the corresponding numeric type. If this is found, a copy of
* the numeric type string is made and returned. Otherwise a null
* pointer is returned.
* If a string is returned, the calling code must free it with delete[].
*
* \param file name of source file for error message
* \param line line number in source file for error message
* \param str type string to be expanded
* \param mode select labelmap using constants from Atom class
* \param lmp pointer to top-level LAMMPS class instance
* \return pointer to expanded string or null pointer */
char *expand_type(const char *file, int line, const std::string &str, int mode, LAMMPS *lmp);
/*! Expand type label string into its equivalent integer-valued numeric type
*
* This function has the same arguments as expand_type() but returns an integer value */
int expand_type_int(const char *file, int line, const std::string &str, int mode, LAMMPS *lmp,
bool verify = false);
/*! Check grid reference for valid Compute or Fix which produces per-grid data
*
* This function checks if a command argument in the input script
* is a valid reference to per-grid data produced by a Compute or Fix.
* If it is, the ID of the compute/fix is returned which the caller must
* free with delete []. It also returns igrid/idata/index integers
* which allow the caller to access the per-grid data.
* A flag is also returned to indicate compute vs fix vs error.
*
* \param errstr name of calling command, e.g. "Fix ave/grid"
* \param ref per-grid reference from input script, e.g. "c_10:grid:data[2]"
* \param nevery frequency at which caller will access fix for per-grid info,
* ignored when reference is to a compute
* \param id ID of Compute or Fix
* \param igrid which grid is referenced (0 to N-1)
* \param idata which data on grid is referenced (0 to N-1)
* \param index which column of data is referenced (0 for vec, 1-N for array)
* \param lmp pointer to top-level LAMMPS class instance
* \return ArgINFO::COMPUTE or FIX or UNKNOWN or NONE */
int check_grid_reference(char *errstr, char *ref, int nevery, char *&id, int &igrid, int &idata,
int &index, LAMMPS *lmp);
/*! Parse grid reference into 3 sub-strings
*
* Format of grid ID reference = id:gname:dname.
* Return vector with the 3 sub-strings.
*
* \param file name of source file for error message
* \param line line number in source file for error message
* \param name complete grid ID
* \param error pointer to Error class
* \return std::vector<std::string> containing the 3 sub-strings */
std::vector<std::string> parse_grid_id(const char *file, int line, const std::string &name,
Error *error);
/*! Make C-style copy of string in new storage
*
* This allocates a storage buffer and copies the C-style or
* C++ style string into it. The buffer is allocated with "new"
* and thus needs to be deallocated with "delete[]".
*
* \param text string that should be copied
* \return new buffer with copy of string */
char *strdup(const std::string &text);
/*! Convert string to lowercase
*
* \param line string that should be converted
* \return new string with all lowercase characters */
std::string lowercase(const std::string &line);
/*! Convert string to uppercase
*
* \param line string that should be converted
* \return new string with all uppercase characters */
std::string uppercase(const std::string &line);
/*! Trim leading and trailing whitespace. Like TRIM() in Fortran.
*
* \param line string that should be trimmed
* \return new string without whitespace (string) */
std::string trim(const std::string &line);
/*! Return string with anything from the first '#' character onward removed
*
* \param line string that should be trimmed
* \return new string without comment (string) */
std::string trim_comment(const std::string &line);
/*! Replace first '*' character in a string with a number, optionally zero-padded
*
* If there is no '*' character in the string, return the original string.
* If the number requires more characters than the value of the *pad*
* argument, do not add zeros; otherwise add as many zeroes as needed to
* the left to make the the number representation *pad* characters wide.
*
* \param name string with file containing a '*' (or not)
* \param step step number to replace the (first) '*'
* \param pad zero-padding (may be zero)
* \return processed string */
std::string star_subst(const std::string &name, bigint step, int pad);
/*! Remove style suffix from string if suffix flag is active
*
*
\verbatim embed:rst
This will try to undo the effect from using the :doc:`suffix command <suffix>`
or the *-suffix/-sf* command-line flag and return correspondingly modified string.
\endverbatim
*
* \param style string of style name
* \param lmp pointer to the LAMMPS class (has suffix_flag and suffix strings)
* \return processed string */
std::string strip_style_suffix(const std::string &style, LAMMPS *lmp);
/*! Check if a string will likely have UTF-8 encoded characters
*
* UTF-8 uses the 7-bit standard ASCII table for the first 127 characters and
* all other characters are encoded as multiple bytes. For the multi-byte
* characters the first byte has either the highest two, three, or four bits
* set followed by a zero bit and followed by one, two, or three more bytes,
* respectively, where the highest bit is set and the second highest bit set
* to 0. The remaining bits combined are the character code, which is thus
* limited to 21-bits.
*
* For the sake of efficiency this test only checks if a character in the string
* has the highest bit set and thus is very likely an UTF-8 character. It will
* not be able to tell this this is a valid UTF-8 character or whether it is a
* 2-byte, 3-byte, or 4-byte character.
*
\verbatim embed:rst
*See also*
:cpp:func:`utils::utf8_subst`
\endverbatim
* \param line string that should be checked
* \return true if string contains UTF-8 encoded characters (bool) */
inline bool has_utf8(const std::string &line)
{
for (auto c : line)
if (c & 0x80U) return true;
return false;
}
/*! Replace known UTF-8 characters with ASCII equivalents
*
\verbatim embed:rst
*See also*
:cpp:func:`utils::has_utf8`
\endverbatim
* \param line string that should be converted
* \return new string with ascii replacements (string) */
std::string utf8_subst(const std::string &line);
/*! Count words in string with custom choice of separating characters
*
* \param text string that should be searched
* \param separators string containing characters that will be treated as whitespace
* \return number of words found */
size_t count_words(const std::string &text, const std::string &separators);
/*! Count words in string, ignore any whitespace matching " \t\r\n\f"
*
* \param text string that should be searched
* \return number of words found */
size_t count_words(const std::string &text);
/*! Count words in C-string, ignore any whitespace matching " \t\r\n\f"
*
* \param text string that should be searched
* \return number of words found */
size_t count_words(const char *text);
/*! Count words in a single line, trim anything from '#' onward
*
* \param text string that should be trimmed and searched
* \param separators string containing characters that will be treated as whitespace
* \return number of words found */
size_t trim_and_count_words(const std::string &text, const std::string &separators = " \t\r\n\f");
/*! Take list of words and join them with a given separator text.
*
* This is the inverse operation of what the split_words() function
* Tokenizer classes do.
*
* \param words STL vector with strings
* \param sep separator string (may be empty)
* \return string with the concatenated words and separators */
std::string join_words(const std::vector<std::string> &words, const std::string &sep);
/*! Take text and split into non-whitespace words.
*
* This can handle strings with single and double quotes, escaped quotes,
* and escaped codes within quotes, but due to using an STL container and
* STL strings is rather slow because of making copies. Designed for
* parsing command-lines and similar text and not for time critical
* processing. Use a tokenizer class if performance matters.
*
\verbatim embed:rst
*See also*
:cpp:class:`Tokenizer`, :cpp:class:`ValueTokenizer`
\endverbatim
* \param text string that should be split
* \return STL vector with the words */
std::vector<std::string> split_words(const std::string &text);
/*! Take multi-line text and split into lines
*
* \param text string that should be split
* \return STL vector with the lines */
std::vector<std::string> split_lines(const std::string &text);
/*! Check if string can be converted to valid integer
*
* \param str string that should be checked
* \return true, if string contains valid a integer, false otherwise */
bool is_integer(const std::string &str);
/*! Check if string can be converted to valid floating-point number
*
* \param str string that should be checked
* \return true, if string contains valid number, false otherwise */
bool is_double(const std::string &str);
/*! Check if string is a valid ID
* ID strings may contain only letters, numbers, and underscores.
*
* \param str string that should be checked
* \return true, if string contains valid id, false otherwise */
bool is_id(const std::string &str);
/*! Check if string is a valid type label, or numeric type, or numeric type range.
* Numeric type or type range may only contain digits or the '*' character.
* Type label strings may not contain a digit, or a '*', or a '#' character as the
* first character to distinguish them from comments and numeric types or type ranges.
* They also may not contain any whitespace. If the string is a valid numeric type
* or type range the function returns 0, if it is a valid type label the function
* returns 1, otherwise it returns -1.
*
* \param str string that should be checked
* \return 0, 1, or -1, depending on whether the string is valid numeric type, valid type label or neither, respectively */
int is_type(const std::string &str);
/*! Determine full path of potential file. If file is not found in current directory,
* search directories listed in LAMMPS_POTENTIALS environment variable
*
* \param path file path
* \return full path to potential file */
std::string get_potential_file_path(const std::string &path);
/*! Read potential file and return DATE field if it is present
*
* \param path file path
* \param potential_name name of potential that is being read
* \return DATE field if present */
std::string get_potential_date(const std::string &path, const std::string &potential_name);
/*! Read potential file and return UNITS field if it is present
*
* \param path file path
* \param potential_name name of potential that is being read
* \return UNITS field if present */
std::string get_potential_units(const std::string &path, const std::string &potential_name);
enum { NOCONVERT = 0, METAL2REAL = 1, REAL2METAL = 1 << 1 };
enum { UNKNOWN = 0, ENERGY };
/*! Return bitmask of available conversion factors for a given property
*
* \param property property to be converted
* \return bitmask indicating available conversions */
int get_supported_conversions(const int property);
/*! Return unit conversion factor for given property and selected from/to units
*
* \param property property to be converted
* \param conversion constant indicating the conversion
* \return conversion factor */
double get_conversion_factor(const int property, const int conversion);
/*! Open a potential file as specified by *name*
*
* If opening the file directly fails, the function will search for
* it in the list of folder pointed to by the environment variable
* ``LAMMPS_POTENTIALS`` (if it is set).
*
* If the potential file has a ``UNITS`` tag in the first line, the
* tag's value is compared to the current unit style setting.
* The behavior of the function then depends on the value of the
* *auto_convert* parameter. If it is a null pointer, then the unit
* values must match or else the open will fail with an error. Otherwise
* the bitmask that *auto_convert* points to is used check for
* compatibility with possible automatic conversions by the calling
* function. If compatible, the bitmask is set to the required
* conversion or ``utils::NOCONVERT``.
*
* \param name file- or pathname of the potential file
* \param lmp pointer to top-level LAMMPS class instance
* \param auto_convert pointer to unit conversion bitmask or ``nullptr``
* \return FILE pointer of the opened potential file or ``nullptr`` */
FILE *open_potential(const std::string &name, LAMMPS *lmp, int *auto_convert);
/*! Convert a time string to seconds
*
* The strings "off" and "unlimited" result in -1
*
* \param timespec a string in the following format: ([[HH:]MM:]SS)
* \return total in seconds */
double timespec2seconds(const std::string &timespec);
/*! Convert a LAMMPS version date to a number
*
* This will generate a number YYYYMMDD from a date string
* (with or without blanks) that is suitable for numerical
* comparisons, i.e. later dates will generate a larger number.
*
* The day may or may not have a leading zero, the month
* is identified by the first 3 letters (so there may be more)
* and the year may be 2 or 4 digits (the missing 2 digits will
* be assumed as 20. That is 04 corresponds to 2004).
*
* No check is made whether the date is valid.
*
* \param date string in the format (Day Month Year)
* \return date code */
int date2num(const std::string &date);
/*! Return current date as string
*
* This will generate a string containing the current date in YYYY-MM-DD format.
*
* \return string with current date */
std::string current_date();
/*! Binary search in a vector of ascending doubles of length N
*
* If the value is smaller than the smallest value in the vector, 0 is returned.
* If the value is larger or equal than the largest value in the vector, N-1 is returned.
* Otherwise the index that satisfies the condition
*
* haystack[index] <= value < haystack[index+1]
*
* is returned, i.e. a value from 1 to N-2. Note that if there are tied values in the
* haystack, always the larger index is returned as only that satisfied the condition.
*
* \param needle search value for which are are looking for the closest index
* \param n size of the haystack array
* \param haystack array with data in ascending order.
* \return index of value in the haystack array smaller or equal to needle */
int binary_search(const double needle, const int n, const double *haystack);
/*! Custom merge sort implementation
*
* This function provides a custom upward hybrid merge sort
* implementation with support to pass an opaque pointer to
* the comparison function, e.g. for access to class members.
* This avoids having to use global variables. For improved
* performance, it uses an in-place insertion sort on initial
* chunks of up to 64 elements and switches to merge sort from
* then on.
*
* \param index Array with indices to be sorted
* \param num Length of the index array
* \param ptr Pointer to opaque object passed to comparison function
* \param comp Pointer to comparison function */
void merge_sort(int *index, int num, void *ptr, int (*comp)(int, int, void *));
} // namespace utils
} // namespace LAMMPS_NS
#endif