ALGOL

Algorigthmic Language (ALGOL) is a family of imperative computer programming languages originally developed in the mid-1950s. It introduced code blocks and the begin...end pairs for delimiting them.

This is container has an implementation of ALGOL 60 from JvanKatwijk that converts Algol 60 to C, and then builds the C program. Your milage may vary with this implementation, but we're lucky it exists at all!

Hello World

begin
  outstring (1, "Hello World!\n");
end;

Coding Guide

Code format

• Full block. Your fragment is a complete begin … end; block. You can write any number of declarations and statements.

Minimal fragment (copy and adapt)

begin
  outstring (1, "Hello from fragment!\n");
end;

Language / runtime

• ALGOL 60 via jff-algol (Algol 60 → C translator, then compile and run).
• Channel 0 = standard input; channel 1 = standard output.

Output and input (prelude procedures)

• outstring (1, "text"); — print string to stdout.
• outinteger (1, n); — print integer.
• outreal (1, x); — print real.
• newline (1); — newline.
• space (1); — space.
• ininteger (0, n); — read one integer from stdin (channel 0) into variable n; must be declared integer.
• inreal (0, x); — read one real from stdin into variable x.

Variables used with ininteger/inreal must be declared (e.g. integer n; or real x;) and passed by value in the prelude sense (the procedure assigns into them).

Common patterns

• Print: begin / outstring (1, "message\n"); / end;
• Declare and print: begin / integer n; n := 42; outinteger (1, n); newline (1); / end;
• Read and echo: begin / integer n; ininteger(0, n); outinteger(1, n); newline(1); / end;
• Arithmetic: use +, -, *, /; assign with :=.

Caveats

• Stdin works when piping input. The generated C program has no argc/argv exposure; command-line arguments are not available from ALGOL.
• Statements end with ;. Variable names and keywords are case-insensitive in ALGOL 60; jff-algol follows that.

Fraglet Scripts

Stdin Int

#!/usr/bin/env -S fragletc --vein=algol
begin
  integer n;
  ininteger(0, n);
  outinteger(1, n);
  newline(1);
end;

Stdin Upper

#!/usr/bin/env -S fragletc --vein=algol
begin
  integer n;
  ininteger(0, n);
  outinteger(1, n);
  newline(1);
end;

Test

#!/usr/bin/env -S fragletc --vein=algol
begin
  outstring (1, "Hello World!\n");
end;

Connections

Container Info