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dsv.js
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dsv.js
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module.exports = dsv;
dsv.version = "0.0.2";
dsv.tsv = dsv("\t");
dsv.csv = dsv(",");
function dsv(delimiter) {
var dsv = {},
reFormat = new RegExp("[\"" + delimiter + "\n]"),
delimiterCode = delimiter.charCodeAt(0);
dsv.parse = function(text, f) {
var o;
return dsv.parseRows(text, function(row, i) {
if (o) return o(row, i - 1);
var a = new Function("d", "return {" + row.map(function(name, i) {
return JSON.stringify(name) + ": d[" + i + "]";
}).join(",") + "}");
o = f ? function(row, i) { return f(a(row), i); } : a;
});
};
dsv.parseRows = function(text, f) {
var EOL = {}, // sentinel value for end-of-line
EOF = {}, // sentinel value for end-of-file
rows = [], // output rows
N = text.length,
I = 0, // current character index
n = 0, // the current line number
t, // the current token
eol; // is the current token followed by EOL?
function token() {
if (I >= N) return EOF; // special case: end of file
if (eol) return eol = false, EOL; // special case: end of line
// special case: quotes
var j = I;
if (text.charCodeAt(j) === 34) {
var i = j;
while (i++ < N) {
if (text.charCodeAt(i) === 34) {
if (text.charCodeAt(i + 1) !== 34) break;
++i;
}
}
I = i + 2;
var c = text.charCodeAt(i + 1);
if (c === 13) {
eol = true;
if (text.charCodeAt(i + 2) === 10) ++I;
} else if (c === 10) {
eol = true;
}
return text.substring(j + 1, i).replace(/""/g, "\"");
}
// common case: find next delimiter or newline
while (I < N) {
var c = text.charCodeAt(I++), k = 1;
if (c === 10) eol = true; // \n
else if (c === 13) { eol = true; if (text.charCodeAt(I) === 10) ++I, ++k; } // \r|\r\n
else if (c !== delimiterCode) continue;
return text.substring(j, I - k);
}
// special case: last token before EOF
return text.substring(j);
}
while ((t = token()) !== EOF) {
var a = [];
while (t !== EOL && t !== EOF) {
a.push(t);
t = token();
}
if (f && !(a = f(a, n++))) continue;
rows.push(a);
}
return rows;
};
dsv.format = function(rows) {
if (Array.isArray(rows[0])) return dsv.formatRows(rows); // deprecated; use formatRows
var fieldSet = {}, fields = [];
// Compute unique fields in order of discovery.
rows.forEach(function(row) {
for (var field in row) {
if (!(field in fieldSet)) {
fields.push(fieldSet[field] = field);
}
}
});
return [fields.map(formatValue).join(delimiter)].concat(rows.map(function(row) {
return fields.map(function(field) {
return formatValue(row[field]);
}).join(delimiter);
})).join("\n");
};
dsv.formatRows = function(rows) {
return rows.map(formatRow).join("\n");
};
function formatRow(row) {
return row.map(formatValue).join(delimiter);
}
function formatValue(text) {
return reFormat.test(text) ? "\"" + text.replace(/\"/g, "\"\"") + "\"" : text;
}
return dsv;
}