5 a68g \- Algol 68 Genie, an Algol 68 interpreter
9 .Op Fl apropos | help | info [string]
10 .Op Fl assertions | Fl noassertions
11 .Op Fl backtrace | Fl nobacktrace
13 .Op Fl check | Fl norun
14 .Op Fl debug | Fl monitor
16 .Op Fl execute Ar unit
18 .Op Fl frame Ar number
19 .Op Fl handles Ar number
23 .Op Fl overhead Ar number
24 .Op Fl pragmats | Fl nopragmats
25 .Op Fl precision Ar number
30 .Op Fl source | Fl nosource
31 .Op Fl stack Ar number
34 .Op Fl timelimit Ar number
35 .Op Fl trace | Fl notrace
36 .Op Fl tree | Fl notree
40 .Op Fl warnings | Fl nowarnings
41 .Op Fl xref | Fl noxref
45 Algol 68 Genie (Algol68G) is an Algol 68 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.
48 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.
50 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.
52 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.
54 Options are not case sensitive. In the list below, uppercase letters are mandatory for recognition. For instance
56 a68g -prec 200 -ti 60 ...
60 a68g -precision 200 -timelimit 60 ...
62 Where numeric arguments are required, suffices k, M or G are allowed for multiplication with 2 ** 10, 2 ** 20 or 2 ** 30 respectively.
65 .It Fl APropos | Help | INfo Ar [string]
66 Print info on options if string is omitted, or print info on string otherwise.
68 .It Fl Assertions | Fl NOAssertions
69 Control elaboration of assertions.
71 .It Fl BACKtrace | Fl NOBACKtrace
72 Control whether a stack backtrace is done in case a runtime-error occurs.
75 Consider [ .. ] and { .. } as being equivalent to ( .. ). Traditional Algol 68 syntax allows ( .. ) to replace [ .. ] in bounds and slices.
77 .It Fl Check | Fl NORun
78 Check syntax only, the interpreter does not start.
80 .It Fl DEBUG | Fl MONitor
81 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.
84 Echo string to standout.
86 .It Fl Execute Ar unit
87 Execute the Algol 68 unit. In this way one-liners can be executed from the command line.
90 Generate an extensive listing.
92 .It Fl FRAME Ar number
93 Set the frame stack size to
97 .It Fl HANDLES Ar number
98 Set the handle space size to
102 .It Fl HEAP Ar number
108 Generate a concise listing.
111 Generate an overview of modes in the listing file.
113 .It Fl OVERHEAD Ar number
114 Set overhead for stack checking.
116 .It Fl PORTcheck | Fl NOPORTcheck
117 Enable or disable portability warning messages.
119 .It Fl PRagmats | Fl NOPRagmats
120 Control elaboration of pragmats.
122 .It Fl PRECision Ar number
123 Set the precision for LONG LONG modes to
127 .It Fl PRELUDElisting
128 Generate a listing of preludes.
131 Print the value yielded by the Algol 68 unit. In this way one-liners can be executed from the command line.
133 .It Fl QUOTEstropping
137 Print reductions made by the parser.
140 Override the norun option.
142 .It Fl SOURCE | Fl NOSOURCE
143 Control the listing of source lines in the listing file.
145 .It Fl STACK Ar number
146 Set the stack size to
151 Generate statistics in the listing file.
153 .It Fl TImelimit Ar number
154 Interrupt the interpreter after
156 seconds, generating a time limit exceeded error.
158 .It Fl TRace | Fl NOTRace
159 Control tracing of the running program.
161 .It Fl TREE | Fl NOTREE
162 Control listing of the syntax tree in the listing file.
165 Generate an overview of unused tags in the listing file.
167 .It Fl UPPERstropping
168 Use upper stropping, which is the default stropping regime.
174 Print the version of the running image of a68g.
176 .It Fl Warnings | Fl NOWarnings
177 Enable warning messages or suppress suppressible warning messages.
179 .It Fl Xref | Fl NOXref
180 Control generation of a cross-reference in the listing file.
185 Author of Algol68G is Marcel van der Veer <algol68g@xs4all.nl>.