On 2018-12-13 23:03, Roel Janssen wrote: > On 13-12-18 17:06, swedebu...@riseup.net wrote: >> On 2018-12-13 16:01, swedebu...@riseup.net wrote: >> snip >> >>> >>> I tried with the file attached but got this because the driver does not >>> support URIs but only host, port, type, token: >> >> Ah, I saw now that you already implemented URI on master :) >> https://github.com/roelj/guile-sparql/blob/master/sparql/driver.scm >> >> When I try calling this >> ;; Example query to wikidata listing cats >> (sparql-query >> "SELECT ?item >> WHERE >> { >> ?item wdt:P31 wd:Q146. >> } >> LIMIT 10 >> " >> #:uri "https://query.wikidata.org/sparql" >> ;; #:port 80 >> #:type >> "application/sparql-results+json" >> ;; #:token "..." >> #:store-backend 'blazegraph >> ) >> >> I get this fine result: >> #<<response> version: (1 . 1) code: 200 reason-phrase: "OK" headers: >> ((date . #<date nanosecond: 0 second: 12 minute: 32 hour: 15 day: 13 >> month: 12 year: 2018 zone-offset: 0>) (content-type >> application/sparql-results+json (charset . "utf-8")) (transfer-encoding >> (chunked)) (connection close) (server . "nginx/1.13.6") (x-served-by . >> "wdqs1005") (access-control-allow-origin . "*") (cache-control public >> (max-age . 300)) (vary accept accept-encoding) (x-varnish . "644531744, >> 572094009, 417977651") (via "1.1 varnish (Varnish/5.1)" "1.1 varnish >> (Varnish/5.1)" "1.1 varnish (Varnish/5.1)") (accept-ranges bytes) (age . >> 0) (x-cache . "cp1079 pass, cp3030 pass, cp3030 pass") (x-cache-status . >> "pass") (server-timing . "cache;desc=\"pass\"") >> (strict-transport-security . "max-age=106384710; includeSubDomains; >> preload") (set-cookie . >> "WMF-Last-Access=13-Dec-2018;Path=/;HttpOnly;secure;Expires=Mon, 14 Jan >> 2019 12:00:00 GMT") (set-cookie . >> "WMF-Last-Access-Global=13-Dec-2018;Path=/;Domain=.wikidata.org;HttpOnly;secure;Expires=Mon, >> 14 Jan 2019 12:00:00 GMT") (x-analytics . "https=1;nocookies=1") >> (x-client-ip . "83.185.90.53")) port: #<input-output: file 8c37e70>> >> >> My problem now is that I don't know how to separate the header from the >> port-file. >> >> Ah, reading here >> https://www.gnu.org/software/guile/manual/html_node/Responses.html#Responses >> I found (response-port). >> > > Here's what I did in SPARQLing-genomics: > https://github.com/UMCUGenetics/sparqling-genomics/blob/master/web/www/pages/query-response.scm#L86 > > So basically: > > (use-modules > (ice-9 receive) > (ice-9 rdelim) > (web response)) > > (receive (header port) > ;; Note: "text/csv" is the only format that is consistent for > multiple SPARQL back-ends (Virtuoso, BlazeGraph, ...) > (sparql-query ... #:type "text/csv") > (if (= (response-code header) 200) ; This means the query went OK. > (call-some-function port) > #f)) ; Deal with errors at the #f. > > (define (call-some-function port) > (let ((line (read-line port))) > (if (eof-object? line) > #t > (begin > (format #t "Line: ~a~%" line) > ;; Tail-recurse until we have processed each line. > (call-some-function port)))))
This would be a really nice addition to the guile manual. Can I submit it as a patch crediting you? > > The SPARQLing-genomics code deals with more error codes, and processes > the lines in a more useful way. > >> Unfortunately this only took me one step further as I run into this >> instead when trying to parse the port with (json->scm): >> >> Backtrace: >> 7 (apply-smob/1 #<catch-closure 9769550>) >> In ice-9/boot-9.scm: >> 705:2 6 (call-with-prompt _ _ #<procedure default-prompt-handle…>) >> In ice-9/eval.scm: >> 619:8 5 (_ #(#(#<directory (guile-user) 9759910>))) >> In ice-9/boot-9.scm: >> 2312:4 4 (save-module-excursion _) >> 3831:12 3 (_) >> In sdb-test.scm: >> 24:1 2 (_) >> In json/parser.scm: >> 311:18 1 (json-read-number _) >> 148:28 0 (read-number _) >> >> json/parser.scm:148:28: In procedure read-number: >> Throw to key `json-invalid' with args `(#<json-parser port: >> #<input-output: string 98dea80>>)'. >> >> Maybe this is a bug in (json)? > > It looks like the JSON response is not (only) JSON, or simply invalid. > Maybe the "text/xml" or "text/csv" content-type will work better for > you. I noticed that each back-end provides their own structure for > XML and JSON, so I used the somewhat quirky CSV format as a > work-for-all response type. Ok, good to know. Is this documented in your guile-sparql docs? > > I hope this helps. Thanks a lot for taking the time to write this. :) I already met receive in the npm importer but I did not really learn to use it yet. So whenever I see multiple objects returned I can part them with receive! Nice. Guile is super nice. And fast it seems when you get it right. -- Cheers Swedebugia