%PDF-
%PDF-
Mini Shell
Mini Shell
'use strict';
var nodes = require('./nodes');
var lib = require('./lib');
var sym = 0;
function gensym() {
return 'hole_' + sym++;
}
// copy-on-write version of map
function mapCOW(arr, func) {
var res = null;
for (var i = 0; i < arr.length; i++) {
var item = func(arr[i]);
if (item !== arr[i]) {
if (!res) {
res = arr.slice();
}
res[i] = item;
}
}
return res || arr;
}
function walk(ast, func, depthFirst) {
if (!(ast instanceof nodes.Node)) {
return ast;
}
if (!depthFirst) {
var astT = func(ast);
if (astT && astT !== ast) {
return astT;
}
}
if (ast instanceof nodes.NodeList) {
var children = mapCOW(ast.children, function (node) {
return walk(node, func, depthFirst);
});
if (children !== ast.children) {
ast = new nodes[ast.typename](ast.lineno, ast.colno, children);
}
} else if (ast instanceof nodes.CallExtension) {
var args = walk(ast.args, func, depthFirst);
var contentArgs = mapCOW(ast.contentArgs, function (node) {
return walk(node, func, depthFirst);
});
if (args !== ast.args || contentArgs !== ast.contentArgs) {
ast = new nodes[ast.typename](ast.extName, ast.prop, args, contentArgs);
}
} else {
var props = ast.fields.map(function (field) {
return ast[field];
});
var propsT = mapCOW(props, function (prop) {
return walk(prop, func, depthFirst);
});
if (propsT !== props) {
ast = new nodes[ast.typename](ast.lineno, ast.colno);
propsT.forEach(function (prop, i) {
ast[ast.fields[i]] = prop;
});
}
}
return depthFirst ? func(ast) || ast : ast;
}
function depthWalk(ast, func) {
return walk(ast, func, true);
}
function _liftFilters(node, asyncFilters, prop) {
var children = [];
var walked = depthWalk(prop ? node[prop] : node, function (descNode) {
var symbol;
if (descNode instanceof nodes.Block) {
return descNode;
} else if (descNode instanceof nodes.Filter && lib.indexOf(asyncFilters, descNode.name.value) !== -1 || descNode instanceof nodes.CallExtensionAsync) {
symbol = new nodes.Symbol(descNode.lineno, descNode.colno, gensym());
children.push(new nodes.FilterAsync(descNode.lineno, descNode.colno, descNode.name, descNode.args, symbol));
}
return symbol;
});
if (prop) {
node[prop] = walked;
} else {
node = walked;
}
if (children.length) {
children.push(node);
return new nodes.NodeList(node.lineno, node.colno, children);
} else {
return node;
}
}
function liftFilters(ast, asyncFilters) {
return depthWalk(ast, function (node) {
if (node instanceof nodes.Output) {
return _liftFilters(node, asyncFilters);
} else if (node instanceof nodes.Set) {
return _liftFilters(node, asyncFilters, 'value');
} else if (node instanceof nodes.For) {
return _liftFilters(node, asyncFilters, 'arr');
} else if (node instanceof nodes.If) {
return _liftFilters(node, asyncFilters, 'cond');
} else if (node instanceof nodes.CallExtension) {
return _liftFilters(node, asyncFilters, 'args');
} else {
return undefined;
}
});
}
function liftSuper(ast) {
return walk(ast, function (blockNode) {
if (!(blockNode instanceof nodes.Block)) {
return;
}
var hasSuper = false;
var symbol = gensym();
blockNode.body = walk(blockNode.body, function (node) {
// eslint-disable-line consistent-return
if (node instanceof nodes.FunCall && node.name.value === 'super') {
hasSuper = true;
return new nodes.Symbol(node.lineno, node.colno, symbol);
}
});
if (hasSuper) {
blockNode.body.children.unshift(new nodes.Super(0, 0, blockNode.name, new nodes.Symbol(0, 0, symbol)));
}
});
}
function convertStatements(ast) {
return depthWalk(ast, function (node) {
if (!(node instanceof nodes.If) && !(node instanceof nodes.For)) {
return undefined;
}
var async = false;
walk(node, function (child) {
if (child instanceof nodes.FilterAsync || child instanceof nodes.IfAsync || child instanceof nodes.AsyncEach || child instanceof nodes.AsyncAll || child instanceof nodes.CallExtensionAsync) {
async = true;
// Stop iterating by returning the node
return child;
}
return undefined;
});
if (async) {
if (node instanceof nodes.If) {
return new nodes.IfAsync(node.lineno, node.colno, node.cond, node.body, node.else_);
} else if (node instanceof nodes.For && !(node instanceof nodes.AsyncAll)) {
return new nodes.AsyncEach(node.lineno, node.colno, node.arr, node.name, node.body, node.else_);
}
}
return undefined;
});
}
function cps(ast, asyncFilters) {
return convertStatements(liftSuper(liftFilters(ast, asyncFilters)));
}
function transform(ast, asyncFilters) {
return cps(ast, asyncFilters || []);
}
// var parser = require('./parser');
// var src = 'hello {% foo %}{% endfoo %} end';
// var ast = transform(parser.parse(src, [new FooExtension()]), ['bar']);
// nodes.printNodes(ast);
module.exports = {
transform: transform
};
Zerion Mini Shell 1.0