A68G(1)

NAME
a68g - Algol 68 Genie, an Algol 68 interpreter

SYNOPSIS
a68g [--apropos | --help | --info -[string]] [--assertions | --no-assertions] [--backtrace | --no-backtrace] [--brackets] [--check | --no-run] [--compile | --no-compile] [--debug | --monitor] [--echo string] [--execute unit | e unit] [--extensive] [--frame number] [--handles number] [--heap number] [--listing] [--moids] [--object | --no-object] [--overhead number] [--optimise | --no-optimise] [--pragmats | --no-pragmats] [--precision number] [--prelude-listing] [--print unit | p unit] [--quote-stropping] [--reductions] [--rerun] [--run] [--source | --no-source] [--stack number] [--statistics] [--strict] [--terminal] [--time-limit number] [--trace | --no-trace] [--tree | --no-tree] [--unused] [--upper-stropping] [--verbose] [--version] [--warnings | --no-warnings] [--xref | --no-xref] filename

DESCRIPTION
Algol 68 Genie (Algol68G) is an Algol 68 compiler-interpreter. It can be used for executing Algol 68 programs or scripts. Algol 68 is a rather lean orthogonal general-purpose language that is a beautiful means for denoting algorithms. Algol 68 was designed as a general-purpose programming language by IFIP Working Group 2.1 (Algorithmic Languages and Calculi) that has continuing responsibility for Algol 60 and Algol 68.

Algol 68 Genie and its documentation can be obtained from

www.xs4all.nl/~jmvdveer/algol.html

OPTIONS
Options are passed to a68g either from the file .a68g.rc in the working directory, the environment variable A68G_OPTIONS, the command-line or from pragmats.

Option precedence is as follows: pragmat options supersede command-line options, command-line options supersede options in environment variable A68G_OPTIONS, A68G_OPTIONS supersedes options in .a68g.rc.

Listing options, tracing options and -pragmat, -nopragmat, take their effect when they are encountered in a left-to-right pass of the program text, and can thus be used, for example, to generate a cross reference for a particular part of the program.

Where numeric arguments are required, suffices k, M or G are allowed for multiplication with 2 ** 10, 2 ** 20 or 2 ** 30 respectively.

--apropos | --help | --info [string]
    Print info on options if string is omitted, or print info on string otherwise.

--assertions | --no-assertions
    Control elaboration of assertions.

--backtrace | --no-backtrace
    Control whether a stack backtrace is done in case a runtime-error occurs.

--brackets
    Consider [ .. ] and { .. } as being equivalent to ( .. ). Traditional Algol 68 syntax allows ( .. ) to replace [ .. ] in bounds and slices.

--check | --no-run
    Check syntax only, the interpreter does not start.

--compile | --no-compile
    Switch compilation of units on or off. Compilation omits many of the runtime checks offered by the interpreter proper. The program is not executed and a shell script is generated combining source code and its shared library. This shell script can be used as a pseudo-executable.

--debug | --monitor
    Start in the monitor. Invoke the monitor in case a runtime-error occurs; the program will pause in the monitor on the line that contains the error.

--echo string
    Echo string to standout.

--execute unit | -e unit
    Execute the Algol 68 unit. In this way one-liners can be executed from the command line.

--extensive
    Generate an extensive listing.

--frame number
    Set the frame stack size to number bytes.

--handles number
    Set the handle space size to number bytes.

--heap number
    Set the heap size to number bytes.

--listing
    Generate a concise listing.

--moids
    Generate an overview of modes in the listing file.

--object | --no-object
    Control the listing of C code in the listing file.

--optimise | --no-optimise
    Switch compilation of units on or off. Compilation omits many of the runtime checks offered by the interpreter proper.

--overhead number
    Set overhead for stack checking.

--portcheck | --no-portcheck
    Enable or disable portability warning messages.

--pragmats | --no-pragmats
    Control elaboration of pragmats.

--precision number
    Set the precision for LONG LONG modes to number significant digits.

--prelude-listing
    Generate a listing of preludes.

--print unit | -p unit
    Print the value yielded by the Algol 68 unit. In this way one-liners can be executed from the command line.

--quote-stropping
    Use quote stropping.

--reductions
    Print reductions made by the parser.

--rerun
    Use compiled code of a previous run.

--run
    Override the --no-run option.

--source | --no-source
    Control the listing of source lines in the listing file.

--stack number
    Set the stack size to number bytes.

--statistics
    Generate statistics in the listing file.

--strict
    Ignores extensions to Algol 68 syntax.

--time-limit number
    Interrupt the interpreter after number seconds, generating a time limit exceeded error.

--trace | --no-trace
    Control tracing of the running program.

--tree | --no-tree
    Control listing of the syntax tree in the listing file.

--unused
    Generate an overview of unused tags in the listing file.

--upper-stropping
    Use upper stropping, which is the default stropping regime.

--verbose
    Use verbose mode.

--version
    Print the version of the running image of a68g.

--warnings | --no-warnings
    Enable warning messages or suppress suppressible warning messages.

--xref | -no-xref
    Control generation of a cross-reference in the listing file.

AUTHOR
Author of Algol68G is Marcel van der Veer <algol68g@xs4all.nl>.