Merge pull request #8 from fogfish/simplify-datalog-syntax

Simplify datalog syntax

.travis.yml

@@ -1,14 +1,16 @@
-script: make && make test
 language: erlang
-otp_release:
-   - 19.2
+dist: trusty
 
 before_install:
-  - curl -O https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.2.1.deb && sudo dpkg -i --force-confnew elasticsearch-5.2.1.deb && sudo service elasticsearch restart
+  - curl -O https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-6.5.4.deb && sudo dpkg -i --force-confnew elasticsearch-6.5.4.deb && sudo service elasticsearch restart
 
-addons:
-  apt:
-    packages:
-      - oracle-java8-set-default
+script:
+   - make
+   - make test
+   - ./rebar3 coveralls send
 
+otp_release:
+   - 20.1
+   - 20.0
+   - 19.2
 

README.md

@@ -30,7 +30,7 @@ If you use `rebar3` you can include the library in your project with
 The library requires Elastic search as a storage back-end. Use the docker container for development purpose.
 
 ```bash
-docker run -it -p 9200:9200 fogfish/elasticsearch:6.2.3
+docker run -p 9200:9200 -d fogfish/elasticsearch:6.2.3
 ```
 
 Build library and run the development console
@@ -52,8 +52,8 @@ elasticlog:start().
 %% deploy a schema
 elasticlog:schema(Sock, #{
    <<"schema:name">> => <<"xsd:string">>,
-   <<"schema:born">> => <<"xsd:string">>,
-   <<"schema:death">> => <<"xsd:string">>,
+   <<"schema:born">> => <<"xsd:date">>,
+   <<"schema:death">> => <<"xsd:date">>,
    <<"schema:title">> => <<"xsd:string">>,
    <<"schema:year">> => <<"xsd:integer">>,
    <<"schema:director">> => <<"xsd:anyURI">>,
@@ -80,18 +80,21 @@ stream:foreach(
 ```
 
 Querying and joining semantical data requires translation of facts into n-ary relation. 
-The library implements a σ function (`.stream`) that produces a stream of tuple from any 
-bucket. It takes a name of bucket as first argument followed by predicate names.
+The library implements a σ function that produces a stream of tuple from any bucket.
+The datalog notation support compact IRI as predicate name. The library uses IRI notation to 
+project ground-truth predicate on table.
 
 
 **Basic queries**
 
 ```erlang
 %%
 %% define a query goal to match a person with `name` equal to `Ridley Scott`.
-Q = "?- person(_, \"Ridley Scott\").
-person(id, name) :- 
-   .stream(\"imdb\", \"rdf:id\", \"schema:name\").".
+Q = "
+   ?- imdb:person(_, \"Ridley Scott\").
+
+   imdb:person(\"rdf:id\", \"schema:name\").
+".
 
 %%
 %% parse and compile a query into executable function
@@ -110,12 +113,14 @@ stream:list(elasticlog:q(F, Sock)).
 ```erlang
 %%
 %% define a query to discover all movies produces in 1987
-Q = "?- h(_, _). 
-movie(id, title, year) :- 
-   .stream(\"imdb\", \"rdf:id\", \"schema:title\", \"schema:year\").
+Q = "
+   ?- movie(_, _). 
+
+   imdb:movie(\"rdf:id\", \"schema:title\", \"schema:year\").
 
-h(id, title) :- 
-   movie(id, title, 1987).".
+   movie(id, title) :- 
+      imdb:movie(id, title, 1987).
+".
 
 %%
 %% parse and compile a query into executable function
@@ -131,17 +136,19 @@ F = datalog:c(elasticlog, datalog:p(Q)).
 stream:list(elasticlog:q(F, Sock)).
 ```
 
-**Predicates**
+**Infix Predicates**
 
 ```erlang
 %%
 %% define a query to discover all movies produces  before 1984
-Q = "?- h(_, _). 
-movie(title, year) :- 
-   .stream(\"imdb\", \"schema:title\", \"schema:year\").
+Q = "
+   ?- movie(_, _).
+
+   imdb:movie(\"rdf:id\", \"schema:title\", \"schema:year\").
 
-h(title, year) :- 
-   movie(title, year), year < 1984.".
+   movie(title, year) :- 
+      imdb:movie(id, title, year), year < 1984.
+".
 
 %%
 %% parse and compile a query into executable function
@@ -164,18 +171,18 @@ stream:list(elasticlog:q(F, Sock)).
 ```erlang
 %%
 %% define a query to discover actors of all movies produced before 1984
-Q = "?- h(_, _). 
-movie(title, year) :- 
-   .stream(\"imdb\", \"schema:title\", \"schema:year\", \"schema:cast\").
+Q = "
+   ?- actors(_, _).
 
-person(id, name) :- 
-   .stream(\"imdb\", \"rdf:id\", \"schema:name\").
+   imdb:movie(\"schema:title\", \"schema:year\", \"schema:cast\").
+   imdb:person(\"rdf:id\", \"schema:name\").
 
-h(title, name) :- 
-   movie(title, year, cast), 
-   .flat(cast), 
-   person(cast, name), 
-   year < 1984.".
+   actors(title, name) :- 
+      imdb:movie(title, year, cast), 
+      .flat(cast), 
+      imdb:person(cast, name), 
+      year < 1984.
+".
 
 %%
 %% parse and compile a query into executable function
@@ -204,17 +211,17 @@ stream:list(elasticlog:q(F, Sock)).
 ```erlang
 %%
 %% define a query to discover all movies with Sylvester Stallone
-Q = "?- h(_). 
-movie(title, cast) :- 
-   .stream(\"imdb\", \"schema:title\", \"schema:cast\").
+Q = "
+   ?- movie(_).
 
-person(id, name) :- 
-   .stream(\"imdb\", \"rdf:id\", \"schema:name\").
+   imdb:movie(\"schema:title\", \"schema:cast\").
+   imdb:person(\"rdf:id\", \"schema:name\").
 
-h(title) :- 
-   person(id, name), 
-   movie(title, id), 
-   name = \"Sylvester Stallone\".".
+   movie(title) :- 
+      imdb:person(id, name), 
+      imdb:movie(title, id), 
+      name = \"Sylvester Stallone\".
+".
 
 %%
 %% parse and compile a query into executable function
@@ -247,9 +254,11 @@ x(_) :-
 ```erlang
 %%
 %% define a query to count release per decade
-Q = "?- movie(_). 
-movie(year) :- 
-   .select(\"imdb\", \"schema:year\"), histogram(10).".
+Q = "
+   ?- imdb:year(_).
+
+   imdb:year(histogram 10 \"schema:year\").
+".
 
 %%
 %% parse and compile a query into executable function
@@ -270,16 +279,16 @@ stream:list(elasticlog:q(F, Sock)).
 ```erlang
 %%
 %% define a query to count releases by 5 top directors
-Q = "?- h(_, _). 
-movie(id) :- 
-   .select(\"imdb\", \"schema:director\"), category(5).
+Q = "
+   ?- top(_, _).
 
-person(id, name) :- 
-   .stream(\"imdb\", \"rdf:id\", \"schema:name\").
+   imdb:director(category 5 \"schema:director\").
+   imdb:person(\"rdf:id\", \"schema:name\").
 
-h(name, id) :-
-   movie(id),
-   person(id, name).".
+   top(name, id) :- 
+      imdb:director(id),
+      imdb:persion(id, name).
+".
 
 %%
 %% parse and compile a query into executable function
@@ -305,9 +314,11 @@ The library support an implicit query constrains. It supports a use-case where c
 ```erlang
 %%
 %% define a query goal to match a person with `name` equal to `Ridley Scott`.
-Q = "?- person(_, \"Ridley Scott\").
-person(id, name) :- 
-   .stream(\"imdb\", \"rdf:id\", \"schema:name\").".
+Q = "
+   ?- imdb:person(_, \"Ridley Scott\").
+
+   imdb:person(\"rdf:id\", \"schema:name\").
+s".
 
 %%
 %% parse and compile a query into executable function

rebar.config

@@ -2,7 +2,7 @@
 
 {deps, [
    datum,
-   datalog,
+   % datalog,
 
    {feta, ".*",
       {git, "https://github.com/fogfish/feta", {branch, master}}
@@ -16,7 +16,19 @@
       {git, "https://github.com/fogfish/semantic", {branch, master}}
    },
 
+   {datalog, ".*",
+      {git, "https://github.com/fogfish/datalog", {branch, master}}
+   },
+
    {esio, ".*",
       {git, "https://github.com/fogfish/esio", {branch, master}}
    }
 ]}.
+
+%%
+%%
+{plugins                , [coveralls]}.
+{cover_enabled          , true}.
+{cover_export_enabled   , true}.
+{coveralls_coverdata    , "/tmp/test/elasticlog/ct.coverdata"}.
+{coveralls_service_name , "travis-ci"}.

rebar.config.script

@@ -0,0 +1,8 @@
+case os:getenv("TRAVIS") of
+  "true" ->
+    JobId   = os:getenv("TRAVIS_JOB_ID"),
+    lists:keystore(coveralls_service_job_id, 1, CONFIG, {coveralls_service_job_id, JobId});
+  _ ->
+    CONFIG
+end.
+

rebar.lock

@@ -1,5 +1,8 @@
 {"1.1.0",
-[{<<"datalog">>,{pkg,<<"datalog">>,<<"1.2.2">>},0},
+[{<<"datalog">>,
+  {git,"https://github.com/fogfish/datalog",
+       {ref,"e61951aca0b115048e59a25bef5edbcbe36d0710"}},
+  0},
  {<<"datum">>,{pkg,<<"datum">>,<<"4.5.0">>},0},
  {<<"esio">>,
   {git,"https://github.com/fogfish/esio",
@@ -30,17 +33,14 @@
  {<<"pipe">>,{pkg,<<"pipes">>,<<"2.0.0">>},2},
  {<<"semantic">>,
   {git,"https://github.com/fogfish/semantic",
-       {ref,"6db551b5bbf9785bc6a168b5726ecc65638e8b06"}},
+       {ref,"d8e2a8c712b13595ae7fda0c0b4ab68c24ea946e"}},
   0},
- {<<"uid">>,
-  {git,"https://github.com/fogfish/uid",
-       {ref,"698ebcb27b273a2f879d8bd24be5f5ea54c98850"}},
-  1}]}.
+ {<<"uid">>,{pkg,<<"uid">>,<<"1.3.3">>},1}]}.
 [
 {pkg_hash,[
- {<<"datalog">>, <<"F9F0434CDFD722304DAFF7BAA036221949968754B9B35109C85304D4A2496D41">>},
  {<<"datum">>, <<"0F7F064A509632C70448F9BC7E7295BD5F9CD6E3207863B176416EF14FD19E0C">>},
  {<<"jsx">>, <<"D2F6E5F069C00266CAD52FB15D87C428579EA4D7D73A33669E12679E203329DD">>},
  {<<"meck">>, <<"1F7B1A9F5D12C511848FEC26BBEFD09A21E1432EADB8982D9A8ACEB9891A3CF2">>},
- {<<"pipe">>, <<"A10DF54F1EC80EAA491EE7BD689C794886E6E668A9F05436514695E9CF5370AE">>}]}
+ {<<"pipe">>, <<"A10DF54F1EC80EAA491EE7BD689C794886E6E668A9F05436514695E9CF5370AE">>},
+ {<<"uid">>, <<"31CA7E3C9D53716A2FF425E18A33E32C141B763D47B174F757D7CAF7E4228A67">>}]}
 ].

src/elasticlog.app.src

@@ -1,7 +1,7 @@
 {application, elasticlog,
    [
       {description, "elastic search datalog"},
-      {vsn,         "0.7.12"},
+      {vsn,         "1.0.0"},
       {modules,     []},
       {registered,  []},
       {applications,[