Add js module

.editorconfig

@@ -17,4 +17,4 @@ indent_size = 2
 [*.tsx]
 indent_size = 2
 [*.json]
-indent_size = 4
+indent_size = 2

js/.gitignore

@@ -0,0 +1,5 @@
+.cache
+build
+dist
+node_modules
+yarn-error.log

js/.npmignore

@@ -0,0 +1,15 @@
+.cache
+.DS_Store
+.gitignore
+.prettierrc.json
+.travis.yml
+.vscode
+concat_lp.sh
+demo
+dist
+node_modules
+rollup.config.js
+test
+tsconfig.json
+tslint.json
+yarn-error.log

js/.prettierrc.json

@@ -0,0 +1,13 @@
+{
+  "overrides": [
+    {
+      "files": "*.ts",
+      "options": {
+        "printWidth": 120,
+        "parser": "typescript",
+        "singleQuote": true,
+        "trailingComma": "es5"
+      }
+    }
+  ]
+}

js/Readme.md

@@ -0,0 +1,3 @@
+# Draco Core
+
+JavaScript module with the Draco knowledge base and helper functions to convert from ASP to Vega-Lite and vice-versa.

js/package.json

@@ -0,0 +1,43 @@
+{
+  "name": "draco-core",
+  "description": "Visualization Knowledge as Constraints.",
+  "version": "0.0.1",
+  "author": "Dominik Moritz",
+  "license": "BSD-3-Clause",
+  "dependencies": {
+    "vega-lite": "^3.0.0-rc8"
+  },
+  "devDependencies": {
+    "@types/jest": "^23.3.9",
+    "jest": "^23.6.0",
+    "prettier": "^1.14.3",
+    "ts-jest": "^23.10.4",
+    "typescript": "^3.1.4"
+  },
+  "scripts": {
+    "test": "jest",
+    "concat": "bash scripts/concat_lp.sh ../asp build",
+    "build": "rm -rf build && tsc && concat",
+    "format": "tslint -p . --fix && prettier --write '{src,test}/**/*.ts'",
+    "lint": "tslint -p . && prettier --list-different '{src,test}/**/*.ts'"
+  },
+  "jest": {
+    "transform": {
+      "^.+\\.tsx?$": "ts-jest"
+    },
+    "testRegex": "(/__tests__/.*|(\\.|/)(test|spec))\\.(jsx?|tsx?)$",
+    "moduleFileExtensions": [
+      "ts",
+      "tsx",
+      "js",
+      "jsx",
+      "json",
+      "node"
+    ],
+    "testPathIgnorePatterns": [
+      "node_modules",
+      "<rootDir>/build",
+      "src"
+    ]
+  }
+}

js/scripts/concat_lp.sh

@@ -0,0 +1,25 @@
+# usage: ./concat_lp.sh srcdir destdir
+
+declare -a files=("topk-lua"
+"define"
+"generate"
+"hard"
+"soft"
+"weights"
+"assign_weights"
+"optimize"
+"output"
+)
+
+output=""
+newline=$'\n\n'
+
+for file in "${files[@]}"
+do
+  path="${1}/${file}.lp"
+  lp=$(cat $path | sed -e s/\`/\'/g)
+  const=$(echo $file | tr a-z A-Z | tr \- _)
+  output+="export const ${const}: string = \`${lp}\`;${newline}"
+done
+
+echo "$output" > $2/constraints.ts

js/src/index.ts

@@ -0,0 +1,151 @@
+import { TopLevelFacetedUnitSpec } from 'vega-lite/build/src/spec';
+
+const REGEX = /(\w+)\(([\w\.\/]+)(,([\w\.]+))?\)/;
+
+/**
+ * Convert from ASP to Vega-Lite.
+ */
+export function asp2vl(facts: string[]): TopLevelFacetedUnitSpec {
+  let mark = '';
+  let url = 'data/cars.json'; // default dataset
+  const encodings: { [enc: string]: any } = {};
+
+  for (const value of facts) {
+    // TODO: Better handle quoted fields. We currently simply remove all ".
+    const cleanedValue = value.replace(/\"/g, '');
+    const negSymbol = value.trim().startsWith(':-'); // TODO: remove this
+    const [_, predicate, first, __, second] = REGEX.exec(cleanedValue) as any;
+
+    if (predicate === 'mark') {
+      mark = first;
+    } else if (predicate === 'data') {
+      url = first;
+    } else if (predicate !== 'violation') {
+      if (!encodings[first]) {
+        encodings[first] = {};
+      }
+      // if it contains the neg symbol, and the field is a boolean field, its value would be false
+      // e.g., for the case ":- zero(e3)"
+      encodings[first][predicate] = second || !negSymbol;
+    }
+  }
+
+  const encoding: { [channel: string]: any } = {};
+
+  for (const e of Object.keys(encodings)) {
+    const enc = encodings[e];
+
+    // if quantitative encoding and zero is not set, set zero to false
+    if (enc.type === 'quantitative' && enc.zero === undefined && enc.bin === undefined) {
+      enc.zero = false;
+    }
+
+    const scale = {
+      ...(enc.log ? { type: 'log' } : {}),
+      ...(enc.zero === undefined ? {} : enc.zero ? { zero: true } : { zero: false }),
+    };
+
+    encoding[enc.channel] = {
+      type: enc.type,
+      ...(enc.aggregate ? { aggregate: enc.aggregate } : {}),
+      ...(enc.field ? { field: enc.field } : {}),
+      ...(enc.stack ? { stack: enc.stack } : {}),
+      ...(enc.bin !== undefined ? { bin: { maxbins: +enc.bin } } : {}),
+      ...(Object.keys(scale).length ? { scale } : {}),
+    };
+  }
+
+  return {
+    $schema: 'https://vega.github.io/schema/vega-lite/v3.json',
+    data: { url: `${url}` },
+    mark,
+    encoding,
+  } as TopLevelFacetedUnitSpec;
+}
+
+/**
+ * Get the array of witnesses from clingo output.
+ * Return undefined if no witnesses were found.
+ */
+export function getModels(result: any) {
+  return (result.Call || []).reduce((arr: any[], el: any) => {
+    el.Witnesses.forEach((d: any) =>
+      arr.push({
+        facts: d.Value,
+        costs: d.Costs,
+      })
+    );
+    return arr;
+  }, []);
+}
+
+export function models2vl(models: any[]) {
+  return models.map(model => asp2vl(model.facts));
+}
+
+/**
+ * Convert from Vega-Lite to ASP.
+ */
+export function vl2asp(spec: TopLevelFacetedUnitSpec): string[] {
+  const facts = [`mark(${spec.mark})`];
+
+  if ('data' in spec && 'url' in spec.data) {
+    facts.push(`data("${spec.data.url}")`);
+  }
+
+  const encoding = spec.encoding || {};
+
+  let i = 0;
+  for (const channel of Object.keys(encoding)) {
+    const eid = `e${i++}`;
+    facts.push(`encoding(${eid})`);
+    facts.push(`channel(${eid},${channel})`);
+
+    let encFieldType = null;
+    let encZero = null;
+    let encBinned = null;
+
+    // translate encodings
+    for (const field of Object.keys(encoding[channel])) {
+      const fieldContent = encoding[channel][field];
+      if (field === 'type') {
+        encFieldType = fieldContent;
+      }
+      if (field === 'bin') {
+        encBinned = fieldContent;
+      }
+      if (field === 'scale') {
+        // translate two boolean fields
+        if ('zero' in fieldContent) {
+          encZero = fieldContent.zero;
+          if (fieldContent.zero) {
+            facts.push(`zero(${eid})`);
+          } else {
+            facts.push(`:- zero(${eid})`);
+          }
+        }
+        if ('log' in fieldContent) {
+          if (fieldContent.log) {
+            facts.push(`log(${eid})`);
+          } else {
+            facts.push(`:-log(${eid})`);
+          }
+        }
+      } else if (field === 'bin') {
+        facts.push(`${field}(${eid},${fieldContent.maxbins})`);
+      } else if (field === 'field') {
+        // fields can have spaces and start with capital letters
+        facts.push(`${field}(${eid},"${fieldContent}")`);
+      } else {
+        // translate normal fields
+        facts.push(`${field}(${eid},${fieldContent})`);
+      }
+    }
+
+    if (encFieldType === 'quantitative' && encZero === null && encBinned === null) {
+      facts.push(`zero(${eid})`);
+    }
+  }
+
+  return facts;
+}

js/test/index.test.ts

@@ -0,0 +1,67 @@
+import { asp2vl, vl2asp } from '../src';
+import { aspSpecs, vlSpecs } from './specs';
+
+test('asp2vl and vl2asp work', () => {
+  for (let i = 0; i < vlSpecs.length; i++) {
+    const aspSpec = aspSpecs[i];
+    const vlSpec = vlSpecs[i];
+    expect([asp2vl(aspSpec), vl2asp(vlSpec).sort()]).toEqual([vlSpec, aspSpec.sort()]);
+  }
+});
+
+test('parses results correctly', () => {
+  expect(
+    asp2vl([
+      'mark(bar)',
+
+      'encoding(e0)',
+      'channel(e0,x)',
+      'field(e0,"foo")',
+      'type(e0,ordinal)',
+
+      'encoding(e1)',
+      'channel(e1,y)',
+      'aggregate(e1,count)',
+      'type(e1,quantitative)',
+      'zero(e1)',
+    ])
+  ).toEqual({
+    $schema: 'https://vega.github.io/schema/vega-lite/v3.json',
+    data: { url: 'data/cars.json' },
+    mark: 'bar',
+    encoding: {
+      x: { field: 'foo', type: 'ordinal' },
+      y: { aggregate: 'count', type: 'quantitative', scale: { zero: true } },
+    },
+  });
+});
+
+test('generates correct asp', () => {
+  expect(
+    vl2asp({
+      $schema: 'https://vega.github.io/schema/vega-lite/v3.json',
+      data: { url: 'data/cars.json' },
+      mark: 'bar',
+      encoding: {
+        x: { field: 'foo', type: 'ordinal' },
+        y: { aggregate: 'count', type: 'quantitative', scale: { zero: true } },
+      },
+    }).sort()
+  ).toEqual(
+    [
+      'data("data/cars.json")',
+      'mark(bar)',
+
+      'encoding(e0)',
+      'channel(e0,x)',
+      'field(e0,"foo")',
+      'type(e0,ordinal)',
+
+      'encoding(e1)',
+      'channel(e1,y)',
+      'aggregate(e1,count)',
+      'type(e1,quantitative)',
+      'zero(e1)',
+    ].sort()
+  );
+});