Initial data commit

Task/CSV-data-manipulation/JavaScript/csv-data-manipulation-1.js

@@ -0,0 +1,76 @@
+(function () {
+    'use strict';
+
+    // splitRegex :: Regex -> String -> [String]
+    function splitRegex(rgx, s) {
+        return s.split(rgx);
+    }
+
+    // lines :: String -> [String]
+    function lines(s) {
+        return s.split(/[\r\n]/);
+    }
+
+    // unlines :: [String] -> String
+    function unlines(xs) {
+        return xs.join('\n');
+    }
+
+    // macOS JavaScript for Automation version of readFile.
+    // Other JS contexts will need a different definition of this function,
+    // and some may have no access to the local file system at all.
+
+    // readFile :: FilePath -> maybe String
+    function readFile(strPath) {
+        var error = $(),
+            str = ObjC.unwrap(
+                $.NSString.stringWithContentsOfFileEncodingError(
+                    $(strPath)
+                    .stringByStandardizingPath,
+                    $.NSUTF8StringEncoding,
+                    error
+                )
+            );
+        return error.code ? error.localizedDescription : str;
+    }
+
+    // macOS JavaScript for Automation version of writeFile.
+    // Other JS contexts will need a different definition of this function,
+    // and some may have no access to the local file system at all.
+
+    // writeFile :: FilePath -> String -> IO ()
+    function writeFile(strPath, strText) {
+        $.NSString.alloc.initWithUTF8String(strText)
+            .writeToFileAtomicallyEncodingError(
+                $(strPath)
+                .stringByStandardizingPath, false,
+                $.NSUTF8StringEncoding, null
+            );
+    }
+
+    // EXAMPLE - appending a SUM column
+
+    var delimCSV = /,\s*/g;
+
+    var strSummed = unlines(
+        lines(readFile('~/csvSample.txt'))
+        .map(function (x, i) {
+            var xs = x ? splitRegex(delimCSV, x) : [];
+
+            return (xs.length ? xs.concat(
+                // 'SUM' appended to first line, others summed.
+                i > 0 ? xs.reduce(
+                    function (a, b) {
+                        return a + parseInt(b, 10);
+                    }, 0
+                ).toString() : 'SUM'
+            ) : []).join(',');
+        })
+    );
+
+    return (
+        writeFile('~/csvSampleSummed.txt', strSummed),
+        strSummed
+    );
+
+})();

Task/CSV-data-manipulation/JavaScript/csv-data-manipulation-2.js

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+const fs = require('fs');
+
+// formats for the data parameter in the function below: {col1: array | function, col2: array | function}
+
+function addCols(path, data) {
+  let csv = fs.readFileSync(path, 'utf8');
+  csv = csv.split('\n').map(line => line.trim());
+  let colNames = Object.keys(data);
+  for (let i = 0; i < colNames.length; i++) {
+    let c = colNames[i];
+    if (typeof data[c] === 'function') {
+      csv = csv.map((line, idx) => idx === 0
+        ? line + ',' + c
+        : line + ',' + data[c](line, idx)
+      );
+    } else if (Array.isArray(data[c])) {
+      csv = csv.map((line, idx) => idx === 0
+        ? line + ',' + c
+        : line + ',' + data[c][idx - 1]
+      );
+    }
+  }
+  fs.createWriteStream(path, {
+    flag: 'w',
+    defaultEncoding: 'utf8'
+  }).end(csv.join('\n'));
+}
+
+addCols('test.csv', {
+    sum: function (line, idx) {
+      let s = 0;
+      line = line.split(',').map(d => +(d.trim()));
+      for (let i = 0; i < line.length; i++) {
+        s += line[i];
+      }
+      return s;
+    },
+    id: function(line, idx) {
+      return idx;
+    }
+  });