|  | Searching a small file database | | |
| | | drhowarddrfine |  |
|  Posted: Tue Jun 24, 2008 4:35 pm Post subject: Searching a small file database |  |
| |  | |
I don't want to use a db manager, like mysql, for such a small
database but I'm finding this trickier than I thought and hope someone
can provide some guidance.
I have a restaurant menu with prices and other info in a small file.
It's set up in a YAML-ish style, if you're familiar with that format.
I'm just looking for some ideas on the best way to retrieve data based
on a "keyword". What complicates things for me is that some of these
keywords might be inside a nested block, such as "prices:".
-navigation
link: link1
link: link2
-menu
chicken:
-roasted
-fried
steak:
-strip
prices:
small: 15.00
medium: 17.00
large: 19.00
-sirloin
prices:
small: 15.00
fish:
-location
In the above example, indentation matters. I am not bound by this
format so better ideas are welcome, but searching for menu->steak-
| Quote: | strip->prices->large returning "19.00" seems logical to me.
|
What complicates things is when I want to do something like
"next_record()". It must tell me there are no more prices in "strip"
and not mistakenly search into the "prices" records of "sirloin".
Is my whole concern my answer, too? That I am trying to write a small
db manager and it's not a simple solution? Or is there simply a
better idea I'm missing?
Originally I did this in XML but felt parsing the tags wasn't any
easier and my format, above, is more readable. I can't just store a
struct in the file because I want it to be editable with any text
editor.
Thanks,
Doc |
| |
| | | Eric Sosman | |
| | Posted: Tue Jun 24, 2008 4:35 pm Post subject: Re: Searching a small file database | |
drhowarddrfine wrote:
| Quote: | I don't want to use a db manager, like mysql, for such a small
database but I'm finding this trickier than I thought and hope someone
can provide some guidance.
I have a restaurant menu with prices and other info in a small file.
It's set up in a YAML-ish style, if you're familiar with that format.
[...]
|
I'm not, but Google is. It seems that libraries for dealing
with YAML in several programming languages, including C, have
already been written. Use one of them.
--
Eric.Sosman@sun.com |
| |
| | | Eric Sosman | |
| | Posted: Tue Jun 24, 2008 4:35 pm Post subject: Re: Searching a small file database | |
| | | |
drhowarddrfine wrote:
| Quote: | On Jun 24, 11:42 am, Eric Sosman <Eric.Sos...@sun.com> wrote:
drhowarddrfine wrote:
I don't want to use a db manager, like mysql, for such a small
database but I'm finding this trickier than I thought and hope someone
can provide some guidance.
I have a restaurant menu with prices and other info in a small file.
It's set up in a YAML-ish style, if you're familiar with that format.
[...]
I'm not, but Google is. It seems that libraries for dealing
with YAML in several programming languages, including C, have
already been written. Use one of them.
But it's not YAML. I don't know that I want to take the time to learn
all of YAML or its libraries. Perhaps because I'm in a bit of a rush
to get this part done. I feel a need to learn how to do this, too,
and not have some library do this for me.
|
Then your problem seems to be more about algorithms than
about the language you implement them in. Seriously: Your
questions to this point would be the same whether you were
implementing in C or Java or Lisp or assembly -- which is
a pretty good indication that they've been addressed to the
wrong forum. (Fora, actually, because I notice you've multi-
posted to at least two newsgroups. Consider your wrist slapped.)
I don't know where to refer you, other than to the YAML
documentation and/or to studying the YAML sources. Yes, I
heard your "it's not YAML," but you said it was "YAML-ish"
so you ought to be able to get some ideas, at least.
Also, you'll need to develop a more precise description of
your format than "YAML-ish but not YAML" before you can even
begin to parse and search it. Remember Douglas Adams' line
about a beverage "almost, but not quite exactly, unlike tea?"
That's how your description reads at the moment, and computers
lack sufficient imagination to fill in the details on their own.
--
Eric.Sosman@sun.com |
| |
| | | drhowarddrfine | |
| | Posted: Tue Jun 24, 2008 4:47 pm Post subject: Re: Searching a small file database | |
On Jun 24, 11:42 am, Eric Sosman <Eric.Sos...@sun.com> wrote:
| Quote: | drhowarddrfine wrote:
I don't want to use a db manager, like mysql, for such a small
database but I'm finding this trickier than I thought and hope someone
can provide some guidance.
I have a restaurant menu with prices and other info in a small file.
It's set up in a YAML-ish style, if you're familiar with that format.
[...]
I'm not, but Google is. It seems that libraries for dealing
with YAML in several programming languages, including C, have
already been written. Use one of them.
--
Eric.Sos...@sun.com
|
But it's not YAML. I don't know that I want to take the time to learn
all of YAML or its libraries. Perhaps because I'm in a bit of a rush
to get this part done. I feel a need to learn how to do this, too,
and not have some library do this for me. |
| |
| | | Bartc | |
| | Posted: Tue Jun 24, 2008 4:50 pm Post subject: Re: Searching a small file database | |
| | | |
"drhowarddrfine" <robbelics@gmail.com> wrote in message
news:63ec1f2d-fe44-4621-b68c-ef748465b41f@2g2000hsn.googlegroups.com...
| Quote: | I have a restaurant menu with prices and other info in a small file.
-navigation
link: link1
link: link2
-menu
chicken:
-roasted
-fried
steak:
-strip
prices:
small: 15.00
medium: 17.00
large: 19.00
-sirloin
prices:
small: 15.00
fish:
-location
In the above example, indentation matters. I am not bound by this
format so better ideas are welcome, but searching for menu->steak-
strip->prices->large returning "19.00" seems logical to me.
What complicates things is when I want to do something like
"next_record()". It must tell me there are no more prices in "strip"
and not mistakenly search into the "prices" records of "sirloin".
Is my whole concern my answer, too? That I am trying to write a small
db manager and it's not a simple solution? Or is there simply a
better idea I'm missing?
|
Are you sure you really want to use C? This looks an ideal job for a rapid
development language. I had a go at this using a toy language, and the
result, which possibly might be helpful, follows below (this code is not
case-sensitive and ! is like a // comment).
If you are going to use C, this code at least shows that you don't need
complex data structures like trees or linked lists; a linear set of records
is stored (or you could use 3 parallel arrays), but the indent level has to
be stored (as 1+). (Because, how large will a restaurant menu ever be?)
This uses a modified form of your menu: no "-" or ":" characters (whatever
they meant), and each indentation is a definite number of "\t" characters
(relying on multiples of 3 spaces might be iffy).
The next_record() function here (as findnext()), will also return any (index
to) records at the same or higher level than current.
Hope this helps.
---------------------------------
type rmenuitem = record(var level,name,value)
var menuitems
var currindex
PROC START=
if not readmenu("menu") then stop fi
forall m in menuitems do
println m
od
!index:=finditem("menu->chicken->fried")
index:=finditem("menu->steak->strip->prices")
if index then
println "Found: ",menuitems[currindex]
while findnext() do
println "Next:",menuitems[currindex]
od
else
println "Not found"
fi
END
FUNCTION FINDITEM(searchstring)=
!return index of item (also in currindex), or 0 if not found
keywords:=splitstring(searchstring,"->")
!println "Keywords=",keywords
currindex:=0
forall i,k in keywords do !i is search level
do
++currindex
if currindex>menuitems.upb then return 0 fi
if menuitems[currindex].level<i then return 0 fi
if menuitems[currindex].name=k then exit fi !ie. break
od
od
return 1
END
FUNCTION FINDNEXT=
!return index of next item after currindex, at same level, otherwise return
0
if currindex=0 or currindex>=menuitems.upb then return 0 fi
currlevel:=menuitems[currindex].level
++currindex
if menuitems[currindex].level<currlevel then return 0 fi
return currindex
END
FUNCTION READMENU(file)=
f:=openfile(file)
if f=0 then return 0 fi
menuitems:=()
nitems:=0
currindex:=0
while not eof(f) do
readln #f,x:"l"
if x="" then loop fi
indent:=0
while left(x)="\t" do
++indent
x:=right(x,-1)
od
sreread()
read name:"n"
read value:"l"
menuitems[++nitems]:=rmenuitem(indent+1,name,value)
od
closefile(f)
return nitems
END
--
Bartc |
| |
| | | drhowarddrfine | |
| | Posted: Tue Jun 24, 2008 6:51 pm Post subject: Re: Searching a small file database | |
| Quote: | Then your problem seems to be more about algorithms than
about the language you implement them in.
--
Eric.Sos...@sun.com
|
You're right, now that you mention it. |
| |
| | | soscpd | |
| | Posted: Tue Jun 24, 2008 7:45 pm Post subject: Re: Searching a small file database | |
Hello Doc, List
Sqlite can be one of your (best, IMHO) options.
LINK
Regards
Rafael |
| |
| | | drhowarddrfine | |
| | Posted: Tue Jun 24, 2008 8:14 pm Post subject: Re: Searching a small file database | |
@Bartc,
Your comment about "how large can a restaurant menu be" is my thought
exactly. Just scanned your code and, if nothing else, it shows my
initial thoughts were along the same line and I have a little more
confidence in proceeding with my own code.
On Jun 24, 2:45 pm, soscpd <sos...@gmail.com> wrote:
| Quote: | Hello Doc, List
Sqlite can be one of your (best, IMHO) options.
LINK
Regards
Rafael
|
I considered sqlite but for such a small amount of data, I just don't
feel this need to install any other programs. |
| |
| | | Martien Verbruggen | |
| | Posted: Tue Jun 24, 2008 8:19 pm Post subject: Re: Searching a small file database | |
On Tue, 24 Jun 2008 14:02:08 -0400,
Eric Sosman <Eric.Sosman@sun.com> wrote:
| Quote: | Remember Douglas Adams' line
about a beverage "almost, but not quite exactly, unlike tea?"
|
Almost, but not quite, entirely unlike tea.
The placement of that comma makes a difference.
Martien
--
| Yes; Windows is great for running &
Martien Verbruggen | developing viruses, for instance. It's also
| very popular, but then again, so is the
| common cold. -- Dave Hinz |
| |
| | | Michael Snoyman | |
| | Posted: Wed Jun 25, 2008 3:06 am Post subject: Re: Searching a small file database | |
On Tue, 24 Jun 2008 13:14:33 -0700, drhowarddrfine wrote:
| Quote: | I considered sqlite but for such a small amount of data, I just don't
feel this need to install any other programs.
|
Actually, with the sqlite amalgamation you only need add two files to
your source tree (sqlite3.c and sqlite3.h). I use sqlite all the time and
can simply pass off binaries with sqlite included. |
| |
|
|
