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Fortran (Wasm)

Fortran is a compiled, imperative programming language designed for numeric computation and scientific computing.

Fortran in LiveCodes is compiled to WebAssembly by LFortran and run in the browser, with no server. This is modern Fortran (free form), not a Fortran 77 subset.

Usage​

Demo:

show code
import { createPlayground } from 'livecodes';

const options = {
  "config": {
    "activeEditor": "script",
    "script": {
      "language": "fortran-wasm",
      "content": "program hello\nprint *, 'Hello, World!'\nend program"
    },
    "mode": "simple",
    "editor": "auto",
    "tools": {
      "status": "full"
    }
  }
};
createPlayground('#container', options);

Communication with JavaScript​

The program runs in the context of the result page. A few helpers are available in the browser global livecodes.fortran object:

  • livecodes.fortran.input: the standard input passed to the program.
  • livecodes.fortran.loaded: a promise that resolves when the compiler has downloaded and the program has run. Other helpers should be used after it resolves.
  • livecodes.fortran.output: the program's standard output.
  • livecodes.fortran.error: the compiler diagnostics, if the code failed to compile.
  • livecodes.fortran.exitCode: the exit code of the program.
  • livecodes.fortran.run: compiles and runs the code again with new input, returning a promise that resolves with output, error and exitCode.

Example:

show code
import { createPlayground } from 'livecodes';

const options = {
  "template": "fortran-wasm",
  "params": {
    "activeEditor": "markup"
  }
};
createPlayground('#container', options);

program hello
print *, 'Hello, World!'
end program

Array sections, whole-array arithmetic and intrinsics behave as expected:

program slice
real :: a(4)
a = [10.0, 20.0, 30.0, 40.0]
print *, a(2:3)      ! 20.0 and 30.0, not all four elements
print *, sum(a)      ! 100.0
end program

READ reads from the stdin pane, in the same way as the other console languages.

Language Info​

Name​

fortran-wasm

Aliases / Extensions​

f90, f95, f03, f08, f, for, ftn, fortran, lfortran

Editor​

script

Compiler​

LFortran compiled to WebAssembly.

Version​

LFortran 0.66.0, with LLVM 22.1.8 and LLD, built with Emscripten 4.0.9.

Code Formatting​

Not currently supported.

Live Reload​

By default, new code changes are sent to the result page for re-evaluation without a full page reload. This behavior can be disabled by adding the code comment ! __livecodes_reload__ to the Fortran code, which forces a full page reload.

This comment can be added in the hiddenContent property of the editor for embedded playgrounds.

Example Usage​

program stats
integer :: i
real :: x(5), total
x = [1.0, 2.0, 3.0, 4.0, 5.0]
total = 0.0
do i = 1, 5
   total = total + x(i)
end do
print *, 'Sum  = ', total
print *, 'Mean = ', total / 5.0
end program

Starter Template​

https://livecodes.io/?template=fortran-wasm

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