SYNOPSIS
int parse_command(string, object|object*, string, destargs...)
DESCRIPTION
/*
Pattern Parser package for LPmud, JnA 1990
Ver 2.0
If you have questions or complaints about this code please refer them
to jna@cd.chalmers.se
This is the old version of parse_command() used in compatibility mode.
*/
#ifdef COMPAT_MODE
/*****************************************************
This is the parser
Left to do 910723:
Fix so alternatives possible after %s in a pattern
*/
/*
Doc for LPC function
int parse_command(string,ob/arr,string,destargs...)
parse Returns 1 if pattern matches
string Given command
ob/arr if arr
array holding the accessible objects
if ob
object from which to recurse and create
the list of accessible objects, normally
ob = environment(this_player())
string Parsepattern as list of words and formats:
Example string = " 'get' / 'take' %i "
Syntax:
'word' obligatory text
[word] optional text
/ Alternative marker
%o Single item, object
%l Single living object
%s Any text
%w Any word
%p Preposition
%i Any items
%d Number 0- or tx(0-99)
destargs This is the list of result variables as in sscanf
One variable is needed for each %_
The return types of different %_ is:
%o Returns an object
%l Returns an object
%s Returns a string of words
%w Returns a string of one word
%p Can on entry hold a list of word in array
or an empty variable
Returns:
if empty variable: a string
if array: array[0]=matched word
%i Returns a special array on the form:
[0] = (int) +(wanted) -(order) 0(all)
[1..n] (object) Objectpointers
%d Returns a number
EXAMPLE
parse_command("take apple",environment(this_player()),
" 'get' / 'take' %i ",items);
*/
/* Hardcoded function names to call in LPC objects
*/
#define QIDFUNC "id" /* Func to query in objects to ack name */
#define QPLURIDFUNC "plural_id" /* As Id but pluralform of name */
#define QADJFUNC "adjectiv_id" /* As Id but ack adjectiv not name */
#define QSHORTFUNC "short" /* Objects shortdescription */
DESCRIPTION
/*
Pattern Parser package for LPmud, JnA 1991
Ver 3.1
If you have questions or complaints about this code please refer them
to jna@cd.chalmers.se
*/
#ifndef COMPAT_MODE
/*****************************************************
This is the parser used by the efun parse_command
*/
/*
General documentation:
parse_command() is one of the most complex efun in LPmud to use. It takes
some effort to learn and use, but when mastered, very powerfull constructs
can be implemented.
Basically parse_command() is a piffed up sscanf operating on word basis. It
works similar to sscanf in that it takes a pattern and a variable set of
destination arguments. It is together with sscanf the only efun to use
pass by reference for other variables than arrays.
To make the efun usefull it must have a certain support from the mudlib,
there is a set of functions that it needs to call to get relevant
information before it can parse in a sensible manner.
In earlier versions it used the normal id() lfun in the LPC objects to
find out if a given object was identified by a certain string. This was
highly inefficient as it could result in hundreds or maybe thousands of
calls when very long commands were parsed.
The new version relies on the LPC objects to give it three lists of 'names'.
1 - The normal singular names.
2 - The plural forms of the names.
3 - The acknowledged adjectives of the object.
These are fetched by calls to the functions:
1 - string *parse_command_id_list();
2 - string *parse_command_plural_id_list();
3 - string *parse_command_adjectiv_id_list();
The only really needed list is the first. If the second does not exist
than the efun will try to create one from the singluar list. For
grammatical reasons it does not always succeed in a perfect way. This is
especially true when the 'names' are not single words but phrases.
The third is very nice to have because it makes constructs like
'get all the little blue ones' possible.
Apart from these functions that should exist in all objects, and which
are therefore best put in /std/object.c there is also a set of functions
needed in /secure/master.c These are not absolutely necessary but they
give extra power to the efun.
Basically these /secure/master.c lfuns are there to give default values
for the lists of names fetched from each object.
The names in these lists are applicable to any and all objects, the first
three are identical to the lfun's in the objects:
string *parse_command_id_list()
- Would normally return: ({ "one", "thing" })
string *parse_command_plural_id_list()
- Would normally return: ({ "ones", "things", "them" })
string *parse_command_adjectiv_id_list()
- Would normally return ({ "iffish" })
The last two are the default list of the prepositions and a single so called
'all' word.
string *parse_command_prepos_list()
- Would normally return: ({ "in", "on", "under" })
string parse_command_all_word()
- Would normally return: "all"
IF you want to use a different language than English but still want the
default pluralform maker to work, you need to replace parse.c with the
following file:
#if 0
* Language configured parse.c
*
#define PARSE_FOREIGN
char *parse_to_plural(str)
char *str;
{
* Your own plural converter for your language *
}
* The numberwords below should be replaced for the new language *
static char *ord1[] = {"", "first", "second", "third", "fourth", "fifth",
"sixth", "seventh", "eighth", "nineth", "tenth",
"eleventh", "twelfth", "thirteenth", "fourteenth",
"fifteenth", "sixteenth", "seventeenth",
"eighteenth","nineteenth"};
static char *ord10[] = {"", "", "twenty","thirty","forty","fifty","sixty",
"seventy", "eighty","ninety"};
static char *sord10[] = {"", "", "twentieth", "thirtieth", "fortieth",
"fiftieth", "sixtieth","seventieth", "eightieth",
"ninetieth"};
static char *num1[] = {"", "one","two","three","four","five","six",
"seven","eight","nine","ten",
"eleven","twelve","thirteen","fourteen","fifteen",
"sixteen", "seventeen","eighteen","nineteen"};
static char *num10[] = {"", "", "twenty","thirty","forty","fifty","sixty",
"seventy", "eighty","ninety"};
#include "parse_english.c" * This parse.c file *
#endif
When all these things are defined parse_command() works best and most
efficient. What follows is the docs for how to use it from LPC:
Doc for LPC function
int parse_command(string, object/object*, string, destargs...)
Returns 1 if pattern matches
string Given command
object* if arr
object array holding the accessible objects
if ob
object from which to recurse and create
the list of accessible objects, normally
ob = environment(this_player())
string Parsepattern as list of words and formats:
Example string = " 'get' / 'take' %i "
Syntax:
'word' obligatory text
[word] optional text
/ Alternative marker
%o Single item, object
%l Living objects
%s Any text
%w Any word
%p One of a list (prepositions)
%i Any items
%d Number 0- or tx(0-99)
destargs This is the list of result variables as in sscanf
One variable is needed for each %_
The return types of different %_ is:
%o Returns an object
%s Returns a string of words
%w Returns a string of one word
%p Can on entry hold a list of word in array
or an empty variable
Returns:
if empty variable: a string
if array: array[0]=matched word
%i Returns a special array on the form:
[0] = (int) +(wanted) -(order) 0(all)
[1..n] (object) Objectpointers
%l Returns a special array on the form:
[0] = (int) +(wanted) -(order) 0(all)
[1..n] (object) Objectpointers
These are only living objects.
%d Returns a number
The only types of % that uses all the loaded information from the objects
are %i and %l. These are in fact identical except that %l filters out
all nonliving objects from the list of objects before trying to parse.
The return values of %i and %l is also the most complex. They return an
array consisting of first a number and then all possible objects matching.
As the typical string matched by %i/%l looks like: 'three red roses',
'all nasty bugs' or 'second blue sword' the number indicates which
of these numerical constructs was matched:
if numeral >0 then three, four, five etc were matched
if numeral <0 then second, twentyfirst etc were matched
if numeral==0 then 'all' or a generic plural form such as 'apples'
were matched.
NOTE!
The efun makes no semantic implication on the given numeral. It does
not matter if 'all apples' or 'second apple' is given. A %i will
return ALL possible objects matching in the array. It is up to the
caller to decide what 'second' means in a given context.
Also when given an object and not an explicit array of objects the
entire recursive inventory of the given object is searched. It is up
to the caller to decide which of the objects are actually visible
meaning that 'second' might not at all mean the second object in
the returned array of objects.
EXAMPLE
if (parse_command("spray car",environment(this_player()),
" 'spray' / 'paint' [paint] %i ",items))
{
If the pattern matched then items holds a return array as described
under 'destargs' %i above.
}
BUGS
/ Features:
Patterns of type: "%s %w %i"
Might not work as one would expect. %w will always succeed so the arg
corresponding to %s will always be empty.
Patterns of the type: 'word' and [word]
The 'word' can not contain spaces. It must be a single word. This is so
because the pattern is exploded on " " (space) and a pattern element can
therefore not contain spaces.
This will be fixed in the future