# Template:Prelude/general.a68

<lang algol68># -*- coding: utf-8 -*- #

COMMENT

``` This is an ALGOL 68 prelude file called prelude/general.
It contains small routine that are not part of any standard,
but are none the less useful and widely used.
```

USAGE

``` PR READ "prelude/general.a68" PR
```

END COMMENT

1. Define some general routines and MODES #

PRIO MIN=8, MAX=8; OP MIN = (INT a,b)INT: (a<b|a|b),

```  MAX = (INT a,b)INT: (a>b|a|b);
```

OP MIN = (REAL a,b)REAL: (a<b|a|b),

```  MAX = (REAL a,b)REAL: (a>b|a|b);
```

MODE IUR = UNION(INT, REAL); OP R = (IUR x)REAL: (x|(REAL r):r, (INT i):REAL(i));

MODE IURUC = UNION(INT, REAL, COMPL); OP C = (IURUC x)COMPL: (x|(COMPL c): c, (REAL r):COMPL(r), (INT i):COMPL(i));

MODE CUCCUS = UNION(CHAR, #[]CHAR,# STRING); OP S = (CUCCUS x)STRING: (x|(STRING s):s, ([]CHAR cc): STRING(cc), (CHAR c):STRING(c));

MODE

``` UCHAR =  STRING, LONGCHAR = UCHAR, USTRING=FLEX[0]LONGCHAR,
LBITS =  UNION(SHORT SHORT BITS,  SHORT BITS,  BITS,  LONG BITS,  LONG LONG BITS),
LBYTES = UNION(SHORT SHORT BYTES, SHORT BYTES, BYTES, LONG BYTES, LONG LONG BYTES),
LINT =   UNION(SHORT SHORT INT,   SHORT INT,   INT,   LONG INT,   LONG LONG INT),
LREAL =  UNION(SHORT SHORT REAL,  SHORT REAL,  REAL,  LONG REAL,  LONG LONG REAL),
LCOMPL = UNION(SHORT SHORT COMPL, SHORT COMPL, COMPL, LONG COMPL, LONG LONG COMPL);
```

MODE SIMPLEOUT = [0]UNION(BOOL, CHAR, STRING, USTRING, LBITS, # LBYTES,# LINT, LREAL, LCOMPL); MODE SIMPLEOUTF = [0]UNION(FORMAT, SIMPLEOUT); MODE USIMPLEOUT = SIMPLEOUT # UNION(SIMPLEOUT, SIMPLEOUTF) #;

PRIO REPR = 8;

1. Use MOID with "*:=" OPerators who's where the returned MODE is often VOIDed for convenience #

MODE MOID = VOID;

PROC raise exception = (STRING type, USIMPLEOUT argv)VOID:(

``` BOOL exception = FALSE;
putf(stand error, (\$g\$, "Exception"," ",type, ": "));
#CASE argv IN#
#  (SIMPLEOUSTRING argv):putf(stand error, argv),#
#  (SIMPLEOUT argv):#
putf(stand error, (\$g" "\$, argv))
#ESAC#;
putf(stand error, \$l\$);
ASSERT (exception)
```

);

1. Python style exceptions #

PROC raise undefined = (USIMPLEOUT argv)VOID: raise exception("Undefined", argv); PROC raise unimplemented=(USIMPLEOUT argv)VOID: raise exception("Unimplemented", argv); PROC raise value error = (USIMPLEOUT argv)VOID: raise exception("Value Error",argv); PROC raise index error = (USIMPLEOUT argv)VOID: raise exception("Index Error",argv); PROC raise type error = (USIMPLEOUT argv)VOID: raise exception("Type Error",argv);

BOOL debug := FALSE, trace := FALSE;

PRIO INKEYS = 5, INVALUES = 5, NOTINKEYS = 5, NOTINVALUES = 5;

1. Algol68G specific declarations #

INT match=0, no match=1, out of memory error=2, other error=3; # for RegEx searches #</lang>

 This is a template. There are many others. See Category:RCTemplates for a complete list of templates.