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feat: add support for backtick-escaped variable names #5

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30 changes: 30 additions & 0 deletions src/token-stream.js
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Original file line number Diff line number Diff line change
Expand Up @@ -46,6 +46,7 @@ TokenStream.prototype.next = function () {
this.isSemicolon() ||
this.isNamedOp() ||
this.isConst() ||
this.isBacktickName() ||
this.isName()
) {
return this.current;
Expand Down Expand Up @@ -454,3 +455,32 @@ TokenStream.prototype.parseError = function (msg) {
var coords = this.getCoordinates();
throw new Error('parse error [' + coords.line + ':' + coords.column + ']: ' + msg);
};

TokenStream.prototype.isBacktickName = function () {
if (this.expression.charAt(this.pos) !== '`') {
return false;
}

var startPos = this.pos;
var i = startPos + 1;
var escaped = false;

for (; i < this.expression.length; i++) {
var c = this.expression.charAt(i);
if (c === '`' && !escaped) {
// Found the closing backtick
var str = this.expression.substring(startPos + 1, i);
this.current = this.newToken(TNAME, str);
this.pos = i + 1;
return true;
}
if (c === '\\' && !escaped) {
escaped = true;
} else {
escaped = false;
}
}

this.parseError('Unterminated backtick string');
return false;
};
108 changes: 78 additions & 30 deletions test/expression.js
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Original file line number Diff line number Diff line change
Expand Up @@ -89,16 +89,18 @@ describe('Expression', function () {
assert.strictEqual(Parser.evaluate('2^(-4)'), 1 / 16);
});

it('\'as\' || \'df\'', function () {
assert.strictEqual(Parser.evaluate('\'as\' || \'df\''), 'asdf');
it("'as' || 'df'", function () {
assert.strictEqual(Parser.evaluate("'as' || 'df'"), 'asdf');
});

it('[1, 2] || [3, 4] || [5, 6]', function () {
assert.deepStrictEqual(Parser.evaluate('[1, 2] || [3, 4] || [5, 6]'), [ 1, 2, 3, 4, 5, 6 ]);
assert.deepStrictEqual(Parser.evaluate('[1, 2] || [3, 4] || [5, 6]'), [1, 2, 3, 4, 5, 6]);
});

it('should fail with undefined variables', function () {
assert.throws(function () { Parser.evaluate('x + 1'); }, Error);
assert.throws(function () {
Parser.evaluate('x + 1');
}, Error);
});

it('x = 3 * 2 + 1', function () {
Expand Down Expand Up @@ -221,7 +223,9 @@ describe('Expression', function () {
});

it('should fail trying to call a non-function', function () {
assert.throws(function () { Parser.evaluate('f()', { f: 2 }); }, Error);
assert.throws(function () {
Parser.evaluate('f()', { f: 2 });
}, Error);
});

it('$x * $y_+$a1*$z - $b2', function () {
Expand Down Expand Up @@ -341,11 +345,36 @@ describe('Expression', function () {
});

it('a[2] + b[3]', function () {
assert.strictEqual(Parser.parse('a[2] + b[3]').simplify({ a: [ 0, 0, 5, 0 ], b: [ 0, 0, 0, 4, 0 ] }).toString(), '9');
assert.strictEqual(Parser.parse('a[2] + b[3]').simplify({ a: [ 0, 0, 5, 0 ] }).toString(), '(5 + b[3])');
assert.strictEqual(Parser.parse('a[2] + b[5 - 2]').simplify({ b: [ 0, 0, 0, 4, 0 ] }).toString(), '(a[2] + 4)');
assert.strictEqual(Parser.parse('a[two] + b[3]').simplify({ a: [ 0, 0, 5, 0 ], b: [ 0, 0, 0, 4, 0 ] }).toString(), '([0, 0, 5, 0][two] + 4)');
assert.strictEqual(Parser.parse('a[two] + b[3]').simplify({ a: [ 0, 'New\nLine', 5, 0 ], b: [ 0, 0, 0, 4, 0 ] }).toString(), '([0, "New\\nLine", 5, 0][two] + 4)');
assert.strictEqual(
Parser.parse('a[2] + b[3]')
.simplify({ a: [0, 0, 5, 0], b: [0, 0, 0, 4, 0] })
.toString(),
'9'
);
assert.strictEqual(
Parser.parse('a[2] + b[3]')
.simplify({ a: [0, 0, 5, 0] })
.toString(),
'(5 + b[3])'
);
assert.strictEqual(
Parser.parse('a[2] + b[5 - 2]')
.simplify({ b: [0, 0, 0, 4, 0] })
.toString(),
'(a[2] + 4)'
);
assert.strictEqual(
Parser.parse('a[two] + b[3]')
.simplify({ a: [0, 0, 5, 0], b: [0, 0, 0, 4, 0] })
.toString(),
'([0, 0, 5, 0][two] + 4)'
);
assert.strictEqual(
Parser.parse('a[two] + b[3]')
.simplify({ a: [0, 'New\nLine', 5, 0], b: [0, 0, 0, 4, 0] })
.toString(),
'([0, "New\\nLine", 5, 0][two] + 4)'
);
});
});

Expand Down Expand Up @@ -597,8 +626,10 @@ describe('Expression', function () {
});

it('a < b or c > d and e <= f or g >= h and i == j or k != l', function () {
assert.strictEqual(parser.parse('a < b or c > d and e <= f or g >= h and i == j or k != l').toString(),
'((((a < b) or (((c > d) and ((e <= f))))) or (((g >= h) and ((i == j))))) or ((k != l)))');
assert.strictEqual(
parser.parse('a < b or c > d and e <= f or g >= h and i == j or k != l').toString(),
'((((a < b) or (((c > d) and ((e <= f))))) or (((g >= h) and ((i == j))))) or ((k != l)))'
);
});

it('x = x + 1', function () {
Expand Down Expand Up @@ -639,12 +670,12 @@ describe('Expression', function () {
assert.strictEqual(Parser.parse('["a", ["b", ["c"]], true, 1 + 2 + 3]').toString(), '["a", ["b", ["c"]], true, ((1 + 2) + 3)]');
});

it('\'as\' || \'df\'', function () {
assert.strictEqual(parser.parse('\'as\' || \'df\'').toString(), '("as" || "df")');
it("'as' || 'df'", function () {
assert.strictEqual(parser.parse("'as' || 'df'").toString(), '("as" || "df")');
});

it('\'A\\bB\\tC\\nD\\fE\\r\\\'F\\\\G\'', function () {
assert.strictEqual(parser.parse('\'A\\bB\\tC\\nD\\fE\\r\\\'F\\\\G\'').toString(), '"A\\bB\\tC\\nD\\fE\\r\'F\\\\G"');
it("'A\\bB\\tC\\nD\\fE\\r\\'F\\\\G'", function () {
assert.strictEqual(parser.parse("'A\\bB\\tC\\nD\\fE\\r\\'F\\\\G'").toString(), '"A\\bB\\tC\\nD\\fE\\r\'F\\\\G"');
});

it('negative numbers are parenthesized', function () {
Expand Down Expand Up @@ -689,7 +720,7 @@ describe('Expression', function () {
it('[4, 3] || [1, 2]', function () {
var expr = parser.parse('x || y');
var f = expr.toJSFunction('x, y');
assert.deepStrictEqual(f([ 4, 3 ], [ 1, 2 ]), [ 4, 3, 1, 2 ]);
assert.deepStrictEqual(f([4, 3], [1, 2]), [4, 3, 1, 2]);
});

it('x = x + 1', function () {
Expand Down Expand Up @@ -717,7 +748,9 @@ describe('Expression', function () {
assert.strictEqual(f(2, 4), 6.283185307179586);

f = expr.toJSFunction(['y']);
assert.throws(function () { return f(4); }, Error);
assert.throws(function () {
return f(4);
}, Error);
});

it('should simplify first', function () {
Expand Down Expand Up @@ -819,7 +852,16 @@ describe('Expression', function () {
});

it('hypot(f(), max(2, x, y))', function () {
assert.strictEqual(parser.parse('hypot(f(), max(2, x, y))').toJSFunction('f, x, y')(function () { return 3; }, 4, 1), 5);
assert.strictEqual(
parser.parse('hypot(f(), max(2, x, y))').toJSFunction('f, x, y')(
function () {
return 3;
},
4,
1
),
5
);
});

it('not x or y and z', function () {
Expand Down Expand Up @@ -863,17 +905,17 @@ describe('Expression', function () {
assert.strictEqual(parser.parse('a or fail()').toJSFunction('a')(true), true);
});

it('\'as\' || s', function () {
assert.strictEqual(parser.parse('\'as\' || s').toJSFunction('s')('df'), 'asdf');
assert.strictEqual(parser.parse('\'as\' || s').toJSFunction('s')(4), 'as4');
it("'as' || s", function () {
assert.strictEqual(parser.parse("'as' || s").toJSFunction('s')('df'), 'asdf');
assert.strictEqual(parser.parse("'as' || s").toJSFunction('s')(4), 'as4');
});

it('\'A\\bB\\tC\\nD\\fE\\r\\\'F\\\\G\'', function () {
assert.strictEqual(parser.parse('\'A\\bB\\tC\\nD\\fE\\r\\\'F\\\\G\'').toJSFunction()(), 'A\bB\tC\nD\fE\r\'F\\G');
it("'A\\bB\\tC\\nD\\fE\\r\\'F\\\\G'", function () {
assert.strictEqual(parser.parse("'A\\bB\\tC\\nD\\fE\\r\\'F\\\\G'").toJSFunction()(), "A\bB\tC\nD\fE\r'F\\G");
});

it('"A\\bB\\tC\\nD\\fE\\r\\\'F\\\\G"', function () {
assert.strictEqual(parser.parse('"A\\bB\\tC\\nD\\fE\\r\\\'F\\\\G"').toJSFunction()(), 'A\bB\tC\nD\fE\r\'F\\G');
assert.strictEqual(parser.parse('"A\\bB\\tC\\nD\\fE\\r\\\'F\\\\G"').toJSFunction()(), "A\bB\tC\nD\fE\r'F\\G");
});

it('"\\u2028 and \\u2029"', function () {
Expand Down Expand Up @@ -904,23 +946,29 @@ describe('Expression', function () {
});

it('a[2]', function () {
assert.strictEqual(parser.parse('a[2]').toJSFunction('a')([ 1, 2, 3 ]), 3);
assert.strictEqual(parser.parse('a[2]').toJSFunction('a')([1, 2, 3]), 3);
});

it('a[2.9]', function () {
assert.strictEqual(parser.parse('a[2.9]').toJSFunction('a')([ 1, 2, 3, 4, 5 ]), 3);
assert.strictEqual(parser.parse('a[2.9]').toJSFunction('a')([1, 2, 3, 4, 5]), 3);
});

it('a[n]', function () {
assert.strictEqual(parser.parse('a[n]').toJSFunction('a,n')([ 1, 2, 3 ], 0), 1);
assert.strictEqual(parser.parse('a[n]').toJSFunction('a,n')([ 1, 2, 3 ], 1), 2);
assert.strictEqual(parser.parse('a[n]').toJSFunction('a,n')([ 1, 2, 3 ], 2), 3);
assert.strictEqual(parser.parse('a[n]').toJSFunction('a,n')([1, 2, 3], 0), 1);
assert.strictEqual(parser.parse('a[n]').toJSFunction('a,n')([1, 2, 3], 1), 2);
assert.strictEqual(parser.parse('a[n]').toJSFunction('a,n')([1, 2, 3], 2), 3);
});

it('a["foo"]', function () {
assert.strictEqual(parser.parse('a["foo"]').toJSFunction('a')({ foo: 42 }), undefined);
});

it('backtick-escaped variable names', function () {
assert.strictEqual(Parser.evaluate('`bfs-id` + 23', { 'bfs-id': 7 }), 30);
assert.strictEqual(Parser.evaluate('`my.complex-var` * 2', { 'my.complex-var': 5 }), 10);
assert.strictEqual(Parser.evaluate('`special!@#$%^&*()` + 10', { 'special!@#$%^&*()': 5 }), 15);
});

it('[1, 2+3, 4*5, 6/7, [8, 9, 10], "1" || "1"]', function () {
var exp = parser.parse('[1, 2+3, 4*5, 6/7, [8, 9, 10], "1" || "1"]');
assert.strictEqual(JSON.stringify(exp.toJSFunction()()), JSON.stringify([1, 5, 20, 6 / 7, [8, 9, 10], '11']));
Expand Down