[IMP] update py.parse to 0.2

bzr revid: xmo@openerp.com-20110929135449-ssommvnyof6auy29
This commit is contained in:
Xavier Morel 2011-09-29 15:54:49 +02:00
parent c94872fc02
commit d32d0c5637
5 changed files with 196 additions and 30 deletions

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@ -0,0 +1,5 @@
repo: 076b192d0d8ab2b92d1dbcfa3da055382f30eaea
node: 87fb1b67d6a13f10a1a328104ee4d4b2c36801ec
branch: default
latesttag: 0.2
latesttagdistance: 1

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@ -0,0 +1 @@
Parser and evaluator of Python expressions

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@ -0,0 +1,14 @@
* Parser
since parsing expressions, try with a pratt parser
http://journal.stuffwithstuff.com/2011/03/19/pratt-parsers-expression-parsing-made-easy/
http://effbot.org/zone/simple-top-down-parsing.htm
Evaluator
---------
* Stop busyworking trivial binary operator
* Make it *trivial* to build Python type-wrappers
* Implement Python's `data model
protocols<http://docs.python.org/reference/datamodel.html#basic-customization>`_
for *all* supported operations, optimizations can come later
* Automatically type-wrap everything (for now anyway)

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@ -5,7 +5,7 @@ var py = {};
NAME = /^[a-zA-Z0-9_]$/;
var create = function (o, props) {
function F() {};
function F() {}
F.prototype = o;
var inst = new F;
for(var name in props) {
@ -13,7 +13,7 @@ var py = {};
inst[name] = props[name];
}
return inst;
}
};
var symbols = {};
var comparators = {};
@ -26,17 +26,17 @@ var py = {};
} else if (this.id === '(end)') {
return '(end)';
} else if (this.id === '(comparator)' ) {
var out = ['(comparator', this.expressions[0]];
var repr = ['(comparator', this.expressions[0]];
for (var i=0;i<this.operators.length; ++i) {
out.push(this.operators[i], this.expressions[i+1]);
repr.push(this.operators[i], this.expressions[i+1]);
}
return out.join(' ') + ')';
return repr.join(' ') + ')';
}
var out = [this.id, this.first, this.second, this.third]
.filter(function (r){return r}).join(' ');
return '(' + out + ')';
}
}
};
function symbol(id, bp) {
bp = bp || 0;
var s = symbols[id];
@ -57,7 +57,7 @@ var py = {};
this.value = id;
return this;
};
};
}
function prefix(id, bp, nud) {
symbol(id).nud = nud || function () {
this.first = expression(bp);
@ -149,7 +149,7 @@ var py = {};
infix('*', 120); infix('/', 120);
infix('//', 120), infix('%', 120);
prefix('-', 130); prefix('+', 130); prefix('~', 130)
prefix('-', 130); prefix('+', 130); prefix('~', 130);
infixr('**', 140);
@ -170,7 +170,7 @@ var py = {};
if (token.id === ')') {
break;
}
this.first.push(expression())
this.first.push(expression());
if (token.id !== ',') {
break;
}
@ -202,11 +202,11 @@ var py = {};
};
infix('[', 150, function (left) {
this.first = left
this.second = expression()
advance("]")
this.first = left;
this.second = expression();
advance("]");
return this;
})
});
symbol('[').nud = function () {
this.first = [];
if (token.id !== ']') {
@ -253,8 +253,8 @@ var py = {};
'!': ['='],
'=': ['='],
'/': ['/']
}
function Tokenizer(str) {
};
function Tokenizer() {
this.states = ['initial'];
this.tokens = [];
}
@ -369,17 +369,18 @@ var py = {};
this.builder().push(character);
return index + 1;
}
}
};
exports.tokenize = function tokenize(str) {
var index = 0,
str = str + '\0',
tokenizer = new Tokenizer(str);
str += '\0';
do {
index = tokenizer.feed(str, index);
} while (index !== str.length)
} while (index !== str.length);
return tokenizer.tokens;
}
};
var token, next;
function expression(rbp) {
@ -403,6 +404,7 @@ var py = {};
}
exports.object = create({}, {});
exports.bool = function (arg) { return !!arg; };
exports.tuple = create(exports.object, {
__contains__: function (value) {
for(var i=0, len=this.values.length; i<len; ++i) {
@ -411,6 +413,15 @@ var py = {};
}
}
return false;
},
toJSON: function () {
return this.values;
}
});
exports.list = exports.tuple;
exports.dict = create(exports.object, {
toJSON: function () {
return this.values;
}
});
@ -420,7 +431,7 @@ var py = {};
next = function () { return toks[++index]; };
return expression();
};
evaluate_operator = function (operator, a, b) {
var evaluate_operator = function (operator, a, b) {
switch (operator) {
case '==': case 'is': return a === b;
case '!=': case 'is not': return a !== b;
@ -428,11 +439,19 @@ var py = {};
case '<=': return a <= b;
case '>': return a > b;
case '>=': return a >= b;
case 'in': return b.__contains__(a);
case 'not in': return !b.__contains__(a);
case 'in':
if (typeof b === 'string') {
return b.indexOf(a) !== -1;
}
return b.__contains__(a);
case 'not in':
if (typeof b === 'string') {
return b.indexOf(a) === -1;
}
return !b.__contains__(a);
}
throw new Error('SyntaxError: unknown comparator [[' + operator + ']]');
}
};
exports.evaluate = function (expr, context) {
switch (expr.id) {
case '(name)':
@ -444,6 +463,14 @@ var py = {};
case '(string)':
case '(number)':
return expr.value;
case '(constant)':
if (expr.value === 'None')
return null;
else if (expr.value === 'False')
return false;
else if (expr.value === 'True')
return true;
throw new Error("SyntaxError: unknown constant '" + expr.value + "'");
case '(comparator)':
var result, left = exports.evaluate(expr.expressions[0], context);
for(var i=0; i<expr.operators.length; ++i) {
@ -455,10 +482,12 @@ var py = {};
}
return true;
case '-':
if (this.second) {
if (expr.second) {
throw new Error('SyntaxError: binary [-] not implemented yet');
}
return -(exports.evaluate(expr.first, context));
case 'not':
return !(exports.evaluate(expr.first, context));
case 'and':
return (exports.evaluate(expr.first, context)
&& exports.evaluate(expr.second, context));
@ -466,16 +495,43 @@ var py = {};
return (exports.evaluate(expr.first, context)
|| exports.evaluate(expr.second, context));
case '(':
if (this.second) {
throw new Error('SyntaxError: functions not implemented yet');
if (expr.second) {
var fn = exports.evaluate(expr.first, context), args=[];
for (var jj=0; jj<expr.second.length; ++jj) {
args.push(exports.evaluate(
expr.second[jj], context));
}
return fn.apply(null, args);
}
var tuple_exprs = expr.first,
tuple_values = [];
for (var i=0, len=tuple_exprs.length; i<len; ++i) {
for (var j=0, len=tuple_exprs.length; j<len; ++j) {
tuple_values.push(exports.evaluate(
tuple_exprs[i], context));
tuple_exprs[j], context));
}
return create(exports.tuple, {values: tuple_values});
case '[':
if (expr.second) {
throw new Error('SyntaxError: indexing not implemented yet');
}
var list_exprs = expr.first, list_values = [];
for (var k=0; k<list_exprs.length; ++k) {
list_values.push(exports.evaluate(
list_exprs[k], context));
}
return create(exports.list, {values: list_values});
case '{':
var dict_exprs = expr.first, dict_values = {};
for(var l=0; l<dict_exprs.length; ++l) {
dict_values[exports.evaluate(dict_exprs[l][0], context)] =
exports.evaluate(dict_exprs[l][1], context);
}
return create(exports.dict, {values: dict_values});
case '.':
if (expr.second.id !== '(name)') {
throw new Error('SyntaxError: ' + expr);
}
return exports.evaluate(expr.first, context)[expr.second.value];
default:
throw new Error('SyntaxError: Unknown node [[' + expr.id + ']]');
}
@ -485,6 +541,6 @@ var py = {};
exports.parse(
exports.tokenize(
str)),
context);;
context);
}
})(typeof exports === 'undefined' ? py : exports)
})(typeof exports === 'undefined' ? py : exports);

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@ -0,0 +1,90 @@
var py = require('../lib/py.js'),
assert = require('assert');
// Literals
assert.strictEqual(py.eval('1'), 1);
assert.strictEqual(py.eval('None'), null);
assert.strictEqual(py.eval('False'), false);
assert.strictEqual(py.eval('True'), true);
assert.strictEqual(py.eval('"somestring"'), 'somestring');
assert.strictEqual(py.eval("'somestring'"), 'somestring');
assert.deepEqual(py.eval("()").toJSON(), []);
assert.deepEqual(py.eval("[]").toJSON(), []);
assert.deepEqual(py.eval("{}").toJSON(), {});
assert.deepEqual(py.eval("(None, True, False, 0, 1, 'foo')").toJSON(),
[null, true, false, 0, 1, 'foo']);
assert.deepEqual(py.eval("[None, True, False, 0, 1, 'foo']").toJSON(),
[null, true, false, 0, 1, 'foo']);
assert.deepEqual(py.eval("{'foo': 1, foo: 2}", {foo: 'bar'}).toJSON(),
{foo: 1, bar: 2});
// Equality tests
assert.ok(py.eval(
"foo == 'foo'", {foo: 'foo'}));
// Inequality
assert.ok(py.eval(
"foo != bar", {foo: 'foo', bar: 'bar'}));
// Comparisons
assert.ok(py.eval('3 < 5'));
assert.ok(py.eval('5 >= 3'));
assert.ok(py.eval('3 >= 3'));
assert.ok(!py.eval('5 < 3'));
assert.ok(py.eval('1 < 3 < 5'));
assert.ok(py.eval('5 > 3 > 1'));
assert.ok(py.eval('1 < 3 > 2 == 2 > -2 not in (0, 1, 2)'));
// string rich comparisons
assert.ok(py.eval(
'date >= current', {date: '2010-06-08', current: '2010-06-05'}));
// Boolean operators
assert.ok(py.eval(
"foo == 'foo' or foo == 'bar'", {foo: 'bar'}));
assert.ok(py.eval(
"foo == 'foo' and bar == 'bar'", {foo: 'foo', bar: 'bar'}));
// - lazyness, second clauses NameError if not short-circuited
assert.ok(py.eval(
"foo == 'foo' or bar == 'bar'", {foo: 'foo'}));
assert.ok(!py.eval(
"foo == 'foo' and bar == 'bar'", {foo: 'bar'}));
// contains (in)
assert.ok(py.eval(
"foo in ('foo', 'bar')", {foo: 'bar'}));
assert.ok(py.eval('1 in (1, 2, 3, 4)'));
assert.ok(!py.eval('1 in (2, 3, 4)'));
assert.ok(py.eval('type in ("url",)', {type: 'url'}));
assert.ok(!py.eval('type in ("url",)', {type: 'ur'}));
assert.ok(py.eval('1 not in (2, 3, 4)'));
assert.ok(py.eval('type not in ("url",)', {type: 'ur'}));
assert.ok(py.eval(
"foo in ['foo', 'bar']", {foo: 'bar'}));
// string contains
assert.ok(py.eval('type in "view"', {type: 'view'}));
assert.ok(!py.eval('type in "view"', {type: 'bob'}));
assert.ok(py.eval('type in "url"', {type: 'ur'}));
// Literals
assert.strictEqual(py.eval('False'), false);
assert.strictEqual(py.eval('True'), true);
assert.strictEqual(py.eval('None'), null);
assert.ok(py.eval('foo == False', {foo: false}));
assert.ok(!py.eval('foo == False', {foo: true}));
// conversions
assert.strictEqual(
py.eval('bool(date_deadline)', {bool: py.bool, date_deadline: '2008'}),
true);
// getattr
assert.ok(py.eval('foo.bar', {foo: {bar: true}}));
assert.ok(!py.eval('foo.bar', {foo: {bar: false}}));
// complex expressions
assert.ok(py.eval(
"state=='pending' and not(date_deadline and (date_deadline < current_date))",
{state: 'pending', date_deadline: false}));
assert.ok(py.eval(
"state=='pending' and not(date_deadline and (date_deadline < current_date))",
{state: 'pending', date_deadline: '2010-05-08', current_date: '2010-05-08'}));;