StringiFor Documentation

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StringiForStrings Fortran Manipulator

A string type for modern Fortran with the methods you miss from Python: split, join, replace, strip, slice, justify, cast to and from numbers, read and write files. One type, one module, pure Fortran 2008.

Tutorial
Cookbook
Reference
API
View on GitHub
🔤

A real string type

One type holding a string of any length: arrays whose elements have different lengths, no trim() everywhere, no silent truncation.

A first string

🔗

A drop-in for character

Assignment, //, the comparison operators and the intrinsics (trim, index, len_trim, repeat, ...) accept a string wherever a character goes.

Strings and I/O

✂️

Split, join, slice

split and partition into tokens (the empty CSV fields kept, if you want), join arrays back, slice with a stride, reverse characters or words, replace, strip, compact whitespace, squeeze repeats, transliterate sets of characters.

String manipulation

🔠

Case and layout

upper, lower, capitalize, camelCase, snake_case, Start Case; letters, digits, punctuation and blanks told apart; pad, center or justify to a width, expand tabs, wrap a paragraph in fully justified lines.

Case conversion

🔢

Numbers in, numbers out

Assign any integer or real kind to a string, cast back with to_number, or with read_number and an error status; ask is_number, is_integer, is_real; hexadecimal representation with hex.

Numbers

📁

Files and paths

Read a file into an array of lines or one string, write it back, read line by line; basedir, basename, extension, glob, wildcard match, temporary names.

Files and paths

⚖️

Comparisons that know more

Longest common prefix of many strings, version numbers compared field by field, start_with, end_with, count.

Comparing

🎨

Encoding and colours

Base64 encode and decode, escape and unescape, ANSI colours and styles for the terminal.

Colours

⚡

Elemental by design

Almost every method is pure or elemental: apply it to a whole array of strings in one statement, use it in pure procedures.

Arrays of strings

🧪

Tested by its own documentation

Every method carries doctests in its source; every example of these pages is a program that is compiled and run to produce the output shown.

The examples

🛠️

Standard Fortran, any build

Fortran 2008, built with FoBiS, fpm, CMake or Make. Three small dependencies, fetched for you.

Installation

🔓

Multi-licensed

GPL v3 for FOSS projects; BSD 2-Clause, BSD 3-Clause or MIT for closed source and commercial ones: pick the license that fits.

Copyrights

Quick start ​

A real session with a small StringiFor program: every answer is one method of the string type.

a terminal session of a StringiFor program: upper case, snake case, reversed words, justified text, version comparison, hexadecimal, number detection

This is the whole program: a select case on the command, one method for each answer.

f90
program sf
!< Quick start: a tiny command line tool, one StringiFor method for each command.
use stringifor
implicit none
type(string)              :: command, text, other
type(string), allocatable :: lines(:)
integer                   :: l

command = argument(1)
text = argument(2)
select case(command%chars())
case('upper')
  call show(text%upper()//'')
case('snake')
  call show(text%snakecase()//'')
case('reverse')
  call show(text%reverse_words()//'')
case('justify')
  call text%justify(lines=lines, width=34)
  do l = 1, size(lines)
    call show('|'//lines(l)//'|')
  enddo
case('newer')
  other = argument(3)
  call show(merge(text, other, text%compare_version(other) > 0)//'')
case('hex')
  call show('0x'//text%hex())
case('number')
  if (text%is_integer()) then
    call show('an integer')
  elseif (text%is_real()) then
    call show('a real')
  else
    call show('not a number')
  endif
endselect

contains
  function argument(n) result(arg)
  !< The n-th command line argument, as a string.
  integer, intent(in)       :: n
  type(string)              :: arg
  character(:), allocatable :: buffer
  integer                   :: length

  call get_command_argument(n, length=length)
  allocate(character(length) :: buffer)
  call get_command_argument(n, value=buffer)
  arg = buffer
  endfunction argument

  subroutine show(answer)
  !< Print an answer, in colour.
  character(*), intent(in) :: answer
  type(string)             :: coloured

  coloured = answer
  print '(A)', coloured%colorize(color_fg='cyan', style='bold_on')
  endsubroutine show
endprogram sf

Grows with your program ​

The same methods take you from a line of text to a report read from a file, cleaned, computed and laid out. This is the output of the program that the tutorial builds step by step:

the report printed by the program of the tutorial

Learn StringiFor step by step in the tutorial, find quick answers in the cookbook, look up every detail in the reference.

Authors ​

Contributions are welcome — see the Contributing page.

Copyrights ​

This project is distributed under a multi-licensing system:

Anyone interested in using, developing, or contributing to this project is welcome — pick the license that best fits your needs.