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improve performance of _determineActualTypes
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The current algorithm is inefficient for unary and binary types. Given
an array containing 1000 elements, for example, we first determine the
types of each element, resulting in an array of 1000 arrays of types.
We then find the intersection of these "sets". This commit introduces
a different approach: for each element, we refine the set of types of
which all previous elements are members rather than filtering the whole
environment each time. This is significantly more efficient for large
arrays.
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@davidchambers
davidchambers committed Jun 24, 2016
1 parent 8835e65 commit c3fa873
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Showing 2 changed files with 137 additions and 106 deletions.
144 changes: 38 additions & 106 deletions index.js
View file
Original file line number Diff line number Diff line change
Expand Up @@ -762,85 +762,15 @@
}
};

// unexpectedType :: Any -> TypeError
var unexpectedType = /* istanbul ignore next */ function(x) {
return new TypeError(
'Unexpected type ' +
LEFT_SINGLE_QUOTATION_MARK + x + RIGHT_SINGLE_QUOTATION_MARK
);
};

// equalTypes :: (Type, Type, Boolean) -> Boolean
var equalTypes = function equalTypes(t1, t2, loose) {
if (t1.type === 'INCONSISTENT' || t2.type === 'INCONSISTENT') return loose;
if (t1.type === 'UNKNOWN' || t2.type === 'UNKNOWN') return true;
switch (t1.type) {
case 'NULLARY':
return t1.type === t2.type && t1.name === t2.name;
case 'UNARY':
return t1.type === t2.type && t1.name === t2.name &&
equalTypes(t1.$1, t2.$1, loose);
case 'BINARY':
return t1.type === t2.type && t1.name === t2.name &&
equalTypes(t1.$1, t2.$1, loose) &&
equalTypes(t1.$2, t2.$2, loose);
case 'ENUM':
return t1.type === t2.type && show(t1) === show(t2);
case 'RECORD':
return t1.type === t2.type && show(t1) === show(t2);
/* istanbul ignore next */
default:
throw unexpectedType(t1.type);
}
};

// chooseType :: (Type, Type) -> Type
var chooseType = function(t1, t2) {
return t1.type === 'UNKNOWN' ? t2 : t1;
};

// mergeTypes :: (Type, Type) -> Type
//
// Either String ??? `mergeTypes` Either ??? Number = Either String Number
var mergeTypes = function(t1, t2) {
return (
t1.type === 'UNARY' ?
UnaryType.from(t1)(chooseType(t1.$1, t2.$1)) :
t1.type === 'BINARY' ?
BinaryType.from(t1)(chooseType(t1.$1, t2.$1),
chooseType(t1.$2, t2.$2)) :
// else
chooseType(t1, t2)
);
};

// commonTypes :: ([[Type]], Boolean) -> [Type]
//
// [[String, RegexFlags], [String, RegexFlags]] ---> [String, RegexFlags]
//
// [[Boolean], [Boolean], [Boolean], [Number]] ---> []
//
// [[Array ???], [Array String], [Array ???]] ---> [Array String]
//
// [[Either String ???], [Either ??? Number]] ---> [Either String Number]
var commonTypes = function(typeses, loose) {
return reduce(typeses[0], [], function(types, t) {
var st = reduce(typeses, {ok: true, type: t}, function(st, types) {
var st$ = reduce(types, {ok: false, type: st.type}, function(st, t) {
var equal = equalTypes(st.type, t, loose);
return {ok: equal || st.ok,
type: equal ? mergeTypes(st.type, t) : st.type};
});
return {type: st$.type, ok: st.ok && st$.ok};
});
return st.ok ? types.concat([st.type]) : types;
});
};

// _determineActualTypes :: (Boolean, [Type], [Object], [Any]) -> [Type]
var _determineActualTypes = function recur(loose, env, seen, values) {
// typeses :: [[Type]]
var typeses = map(values, function(value) {
// _determineActualTypes :: ... -> [Type]
var _determineActualTypes = function recur(
loose, // :: Boolean
env, // :: [Type]
types, // :: [Type]
seen, // :: [Object]
values // :: [Any]
) {
var refine = function(types, value) {
var seen$;
if (typeof value === 'object' && value != null ||
typeof value === 'function') {
Expand All @@ -851,24 +781,30 @@
} else {
seen$ = seen;
}
return chain(env, function(t) {
return chain(types, function(t) {
return (
t.name === 'sanctuary-def/Nullable' || !t._test(value) ?
[] :
t.type === 'UNARY' ?
map(recur(loose, env, seen$, t._1(value)), UnaryType.from(t)) :
map(recur(loose, env, env, seen$, t._1(value)),
UnaryType.from(t)) :
t.type === 'BINARY' ?
BinaryType.xprod(t,
recur(loose, env, seen$, t._1(value)),
recur(loose, env, seen$, t._2(value))) :
t.$1.type === 'UNKNOWN' ?
recur(loose, env, env, seen$, t._1(value)) :
[t.$1],
t.$2.type === 'UNKNOWN' ?
recur(loose, env, env, seen$, t._2(value)) :
[t.$2]) :
// else
[t]
);
});
});
};

return isEmpty(values) ?
[Unknown] :
or(commonTypes(typeses, loose), [Inconsistent]);
or(reduce(values, types, refine), loose ? [Inconsistent] : []);
};

// rejectInconsistent :: [Type] -> [Type]
Expand All @@ -878,20 +814,22 @@
});
};

// determineActualTypesStrict :: ([Type], [Any]) -> [Type]
var determineActualTypesStrict = function(env, values) {
return rejectInconsistent(_determineActualTypes(false, env, [], values));
// determineActualTypesStrict :: ([Type], [Type], [Any]) -> [Type]
var determineActualTypesStrict = function(env, types, values) {
var types$ = _determineActualTypes(false, env, types, [], values);
return rejectInconsistent(types$);
};

// determineActualTypesLoose :: ([Type], [Any]) -> [Type]
var determineActualTypesLoose = function(env, values) {
return rejectInconsistent(_determineActualTypes(true, env, [], values));
// determineActualTypesLoose :: ([Type], [Type], [Any]) -> [Type]
var determineActualTypesLoose = function(env, types, values) {
var types$ = _determineActualTypes(true, env, types, [], values);
return rejectInconsistent(types$);
};

// valuesToPairs :: ([Type], [Any]) -> [Pair Any [Type]]
var valuesToPairs = function(env, values) {
return map(values, function(x) {
return [x, determineActualTypesLoose(env, [x])];
return [x, determineActualTypesLoose(env, env, [x])];
});
};

Expand Down Expand Up @@ -942,8 +880,11 @@
}
}
if (has(typeVarName, typeVarMap)) {
okTypes = filterTypesByValues(typeVarMap[typeVarName].types,
values);
okTypes = _determineActualTypes(false,
env,
typeVarMap[typeVarName].types,
[],
values);
if (isEmpty(okTypes)) {
return Left(typeVarConstraintViolation2(
name,
Expand All @@ -958,7 +899,7 @@
));
}
} else {
okTypes = determineActualTypesStrict(env, values);
okTypes = determineActualTypesStrict(env, env, values);
if (isEmpty(okTypes) && !isEmpty(values)) {
return Left(typeVarConstraintViolation(
name,
Expand Down Expand Up @@ -1032,7 +973,7 @@

default:
return Right({typeVarMap: typeVarMap,
types: determineActualTypesStrict(env, values)});
types: determineActualTypesStrict(env, env, values)});
}
};
};
Expand Down Expand Up @@ -1064,21 +1005,12 @@
};

// test :: ([Type], Type, Any) -> Boolean
var test = $.test = function(_env, t, x) {
$.test = function(_env, t, x) {
var env = applyParameterizedTypes(_env);
var f = _satisfactoryTypes(env, 'name', {}, [t], 0);
return f({}, t, [x], [], []).isRight;
};

// filterTypesByValues :: ([Type], [Any]) -> [Type]
var filterTypesByValues = function(env, values) {
return filter(env, function(t) {
return all(values, function(x) {
return test(env, t, x);
});
});
};

// invalidArgumentsLength :: (String, Integer, Integer) -> Error
var invalidArgumentsLength = function(name, expectedLength, actualLength) {
return new TypeError(
Expand Down
99 changes: 99 additions & 0 deletions test/index.js
View file
Original file line number Diff line number Diff line change
Expand Up @@ -828,6 +828,33 @@ describe('def', function() {
eq(length(vm.runInNewContext('["foo", "bar", "baz"]')), 3);
});

it('accommodates circular references', function() {
// id :: a -> a
var id = def('id', {}, [a, a], R.identity);

var x = {name: 'x'};
var y = {name: 'y'};
x.y = y;
y.x = x;

eq(id(x), x);

var z = [];
z.push(z);

throws(function() { id(z); },
errorEq(TypeError,
'Type-variable constraint violation\n' +
'\n' +
'id :: a -> a\n' +
' ^\n' +
' 1\n' +
'\n' +
'1) [<Circular>] :: Array ???\n' +
'\n' +
'Since there is no type of which all the above values are members, the type-variable constraint has been violated.\n'));
});

it('supports custom types', function() {
// AnonJust :: a -> AnonMaybe a
var AnonJust = function(x) {
Expand Down Expand Up @@ -1711,6 +1738,65 @@ describe('def', function() {
'2) [1, 2, 3] :: Array Number\n' +
'\n' +
'Since there is no type of which all the above values are members, the type-variable constraint has been violated.\n'));

// f :: a -> a -> a -> a
var f = def('f', {}, [a, a, a, a], function(x, y, z) { return x; });

throws(function() { f(Left('abc'), Left(/XXX/)); },
errorEq(TypeError,
'Type-variable constraint violation\n' +
'\n' +
'f :: a -> a -> a -> a\n' +
' ^ ^\n' +
' 1 2\n' +
'\n' +
'1) Left("abc") :: Either String ???\n' +
'\n' +
'2) Left(/XXX/) :: Either RegExp ???\n' +
'\n' +
'Since there is no type of which all the above values are members, the type-variable constraint has been violated.\n'));

throws(function() { f(Right(123), Right(/XXX/)); },
errorEq(TypeError,
'Type-variable constraint violation\n' +
'\n' +
'f :: a -> a -> a -> a\n' +
' ^ ^\n' +
' 1 2\n' +
'\n' +
'1) Right(123) :: Either ??? Number\n' +
'\n' +
'2) Right(/XXX/) :: Either ??? RegExp\n' +
'\n' +
'Since there is no type of which all the above values are members, the type-variable constraint has been violated.\n'));

throws(function() { f(Left('abc'), Right(123), Left(/XXX/)); },
errorEq(TypeError,
'Type-variable constraint violation\n' +
'\n' +
'f :: a -> a -> a -> a\n' +
' ^ ^\n' +
' 1 2\n' +
'\n' +
'1) Right(123) :: Either ??? Number\n' +
'\n' +
'2) Left(/XXX/) :: Either RegExp ???\n' +
'\n' +
'Since there is no type of which all the above values are members, the type-variable constraint has been violated.\n'));

throws(function() { f(Left('abc'), Right(123), Right(/XXX/)); },
errorEq(TypeError,
'Type-variable constraint violation\n' +
'\n' +
'f :: a -> a -> a -> a\n' +
' ^ ^\n' +
' 1 2\n' +
'\n' +
'1) Right(123) :: Either ??? Number\n' +
'\n' +
'2) Right(/XXX/) :: Either ??? RegExp\n' +
'\n' +
'Since there is no type of which all the above values are members, the type-variable constraint has been violated.\n'));
});

it('supports arbitrary nesting of types', function() {
Expand Down Expand Up @@ -1835,6 +1921,19 @@ describe('def', function() {
'\n' +
'Since there is no type of which all the above values are members, the type-variable constraint has been violated.\n'));

throws(function() { concat([[1, 2, 3], [Right(42), Left('XXX')]]); },
errorEq(TypeError,
'Type-variable constraint violation\n' +
'\n' +
'concat :: Array a -> Array a -> Array a\n' +
' ^\n' +
' 1\n' +
'\n' +
'1) [1, 2, 3] :: Array Number\n' +
' [Right(42), Left("XXX")] :: Array (Either String Number)\n' +
'\n' +
'Since there is no type of which all the above values are members, the type-variable constraint has been violated.\n'));

// concatNested :: [[a]] -> [[a]] -> [[a]]
var concatNested =
def('concatNested',
Expand Down

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