Making progress but still in the trenches…
On Oct 5, 3:29 pm, Alan <a...@malloys.org> wrote:
> No, that compiler message is the one that comes up when your Clojure
> parens don't line up; problems in the regex wouldn't appear until
> runtime. It looks like I put too many close-parens after .find. Try
> changing the offending line to:
>
> (re-groups (doto (re-matcher pattern line) .find))
Making this change now runs further until informing me that…
clojure.java.io$reader cannot be cast to java.io.BufferedReader
[Thrown class java.lang.ClassCastException]
>
> Also it occurred to me that my (split) doesn't handle the commas you
> have, so the regex should probably be something more like #"[ ,]+"
okay, thanks :)
>
> On Oct 5, 2:49 pm, Avram <aav...@me.com> wrote:
>
>
>
> > Alan, thanks for your response, I'm still new at this. Running it,
> > the part with refer had an issue, but I tinkered and got past that on
> > line #3.
> > I also added a print statement to see what the output looks like, but
> > there appears to be a hidden unmatched delimiter somewhere (??). I'm
> > digging around for it… i suppose it is in the regex?
>
> > (use 'clojure.java.io)
> > (require 'clojure.string)
> > ;;(refer 'clojure.string :only [split])
> > (refer 'clojure.string :only '(split) )
>
> > (let [pattern #"case when (\\S+) in \\(([^)]+)\\) then (\\S+) as (\\S
> > +)"]
> > (with-open [sql-in (reader "/Users/avram/Downloads/pg.sql")]
> > (doseq [line (line-seq reader)]
> > (let [[_ in-str then-str as-str]
> > (re-groups (doto (re-matcher pattern line) .find)))
> > in-list (split #"\\s+" in-str)]
> > ;;now do whatever you want with in-list, then-str, as-str
> > (print in-str)
> > ))))
>
> > java.lang.Exception: Unmatched delimiter: )
> > [Thrown class clojure.lang.LispReader$ReaderException]
>
> > Restarts:
> > 0: [QUIT] Quit to the SLIME top level
> > 1: [CAUSE1] Invoke debugger on cause Unmatched delimiter: ) [Thrown
> > class java.lang.Exception]
>
> > Backtrace:
> > 0: clojure.lang.LispReader.read(LispReader.java:180)
> > 1: clojure.core$read.invoke(core.clj:2868)
> > 2: clojure.core$read.invoke(core.clj:2866)
>
> > I'll study this and tinker on..
>
> > Many thanks,
> > ~Avram
>
> > On Oct 5, 2:10 pm, Alan <a...@malloys.org> wrote:
>
> > > (use 'clojure.java.io)
> > > (require 'clojure.string)
> > > (refer 'clojure.string :only [split])
>
> > > (let [pattern #"case when (\\S+) in \\(([^)]+)\\) then (\\S+) as (\\S
> > > +)"]
> > > (with-open [sql-in (reader "/path/to/file")]
> > > (doseq [line (line-seq reader)]
> > > (let [[_ in-str then-str as-str]
> > > (re-groups (doto (re-matcher pattern line) .find)))
> > > in-list (split #"\\s+" in-str)]
> > > ;;now do whatever you want with in-list, then-str, as-str
> > > ))))
>
> > > Not tested at all, but this is how I'd approach it - read a bunch of
> > > lines, split them into useable chunks with a regex, and then process
> > > each line. The regex will probably need tuning for your data set if
> > > not every line looks exactly like your example, but hopefully you get
> > > the idea.
>
> > > On Oct 5, 11:45 am, Avram <aav...@me.com> wrote:
>
> > > > Hello Clojurians,
>
> > > > I'm a beginner with clojure, but feel I have a situation that macros
> > > > might be well-suited.
>
> > > > The problem description is that I have a few sql files with a couple
> > > > hundred lines of ANSI SQL. These files contain many SQL statements
> > > > like the following:
>
> > > > case when a in ('Q1', 'Q3', 'Q8', 'Q9') then textvar end as qv100,
>
> > > > The task here, is that I need to convert these ANSI SQL files to
> > > > something that can be run in Hive SQL. My current belief is that Hive
> > > > SQL does not support "in" clauses (http://wiki.apache.org/hadoop/Hive/
> > > > LanguageManual/UDF), so I need to convert the above snippet to
> > > > explicit assignments like this:
>
> > > > case when a='Q1' then textvar when a='Q3' then textvar when a='Q8'
> > > > then textvar when a='Q9' then textvar end as qv100,
>
> > > > Thus, for each value in the "in" clause there will be a "when a=value"
> > > > item.
>
> > > > So, I think I need a function or macro to read an sql file, identify
> > > > all "case when" statements in the file where there is also an "in"
> > > > clause, and translate the "in" clause to the explicit assignments, and
> > > > output a corrected Hive-ready sql file. A complicating factor is that
> > > > since there are single-quotes embedded in each line of the "in" clause
> > > > statements, they likely need to be escaped a priori somehow.
>
> > > > Any thoughts, comments, solutions, or advice on how to tackle this
> > > > with clojure much appreciated.
> > > > Thanks in advance!
>
> > > > Regards,
> > > > ~Avram
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