/
pp.js
188 lines (186 loc) · 8.27 KB
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pp.js
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if (typeof LambdaJS == 'undefined') var LambdaJS = {};
(function(ns) {
with (UI) {
var append = function(child) { return function(node) {
node.appendChild($node(child)); return node;
}; };
var reduce = function() { var args=arguments; return function(node) {
var arr = []; arr.push.apply(arr, args);
return arr.reduce(function(a1, a2) {
return a1.concat((a2 instanceof Array) ? a2 : [a2]);
}, []).reduce(function(x, f) {
return ((typeof f == 'function') ? f : append(f))(x);
}, node);
}; };
var appendParen = function(child){ return reduce('(', child, ')'); };
ns.PP = {
JavaScript: function() {
var self = new ns.PP.Lambda();
self.pp = self._pp;
self.name = 'JavaScript';
self.lambda = function(argNodes, bodyNode) {
var lambda = $new('span', {
klass: 'lambda', child: 'function'
});
return reduce(lambda, '(', argNodes.shift(),
argNodes.map(function(arg) {
return reduce([ ',', arg ]);
}), ')', self.body(bodyNode));
};
self.body = function(bodyNode) {
return reduce('{ return ', bodyNode, ' }');
};
self.apply = function(fun, arg){ return reduce(fun, arg); };
self.arg = function(arg) {
var argNode = self._pp(arg);
var paren = $new('span', { klass: 'argument' });
return append(appendParen(argNode)(paren));
};
return self;
},
JavaScript18: function() {
var self = new ns.PP.JavaScript();
self.body = function(body){ return reduce(' ', body); };
return self;
},
Lambda: function() {
var self = { name: 'Lambda', callback: function(){} };
self.setCallback = function(func){ self.callback = func; };
self.pp = function(exp){
var node = self._pp(exp);
if (exp.type == 'App') {
node = $new('span', { child: [ '(', node, ')' ] });
}
return node;
};
self._pp = function(exp) {
return $node(LambdaJS.Util.promote(exp).pp(self));
};
self.lambda = function(argNodes, bodyNode) {
var lambda = $new('span', {
klass: 'lambda', child: '\u03bb'
});
return reduce(lambda, argNodes, '.', bodyNode);
};
self.apply = function(fun, arg){ return reduce(fun,' ',arg); };
self.arg = function(arg) {
var argNode = self._pp(arg);
if (arg.type != 'Var') {
var paren = $new('span', { klass: 'argument' });
return append(appendParen(argNode)(paren));
} else {
argNode.className += ' argument';
return append(argNode);
}
};
self.markBound = function(exp, v) {
switch (exp.type) {
case 'Var':
if (exp.v == v.v) {
(exp = exp.clone()).bound=true;
}
break;
case 'App':
exp.fun = self.markBound(exp.fun, v);
exp.arg = self.markBound(exp.arg, v);
break;
case 'Abs':
if (exp.arg.v != v.v) {
exp.body = self.markBound(exp.body, v);
}
break;
}
return exp;
};
self.ppApp = function(app) {
var fun = app.fun;
var arg = app.arg;
var klass = 'application';
var node;
if (app.marked) {
node = $new('span', { klass: klass + ' marked' });
fun.body = self.markBound(fun.body, fun.arg);
} else if (app.redex) {
node = $new('a', { klass: klass + ' redex shadowed' });
new UI.Observer(node, 'onclick', function(e) {
app.marked = true;
self.callback();
self.callback = function(){};
e.stop();
});
new UI.Observer(node, 'onmouseover', function(e) {
if (/shadowed/.test(node.className)) {
node.className = node.className.split(/\s+/)
.filter(function(x){ return x!='shadowed'; })
.join(' ');
}
e.stop();
});
new UI.Observer(node, 'onmouseout', function(e) {
node.className += ' shadowed';
});
} else {
node = $new('span', { klass: klass });
}
fun = self._pp(fun);
var appendFun = (app.fun.type == 'Abs') ?
appendParen(fun) : append(fun);
var appendArg = self.arg(app.arg);
return self.apply(appendFun, appendArg)(node);
};
self.ppAbs = function(abs) {
var arg = self._pp(abs.arg);
arg.className += ' binding';
var body = abs.body;
var args = [ arg ];
var node;
var klass = 'abstraction';
if (abs.marked) {
abs.body = self.markBound(abs.body, abs.arg);
node = $new('span', { klass: klass + ' marked' });
} else if (abs.redex) {
node = $new('a', {
klass: klass + ' redex shadowed'
});
new UI.Observer(node, 'onclick', function(e) {
abs.marked = true;
self.callback();
self.callback = function(){};
e.stop();
});
new UI.Observer(node, 'onmouseover', function(e) {
if (/shadowed/.test(node.className)) {
node.className = node.className.split(/\s+/)
.filter(function(x){ return x!='shadowed'; })
.join(' ');
}
e.stop();
});
new UI.Observer(node, 'onmouseout', function(e) {
node.className += ' shadowed';
});
} else {
while (body.type == 'Abs') {
if (body.marked || body.redex) break;
args.push(self._pp(body.arg));
body = body.body;
}
node = $new('span', {
klass: klass
});
}
return self.lambda(args, self._pp(body))(node);
};
self.ppVar = function(v) {
var klass = 'variable';
if (v.bound) klass = [ klass, 'bound' ].join(' ');
var span = $new('span', {
klass: klass, child: v.v+''
});
return span;
};
return self;
}
};
}
})(LambdaJS);