Utilities for the snapdragon parser/compiler.
npm install snapdragon-util> Utilities for the snapdragon parser/compiler.
Please consider following this project's author, Jon Schlinkert, and consider starring the project to show your :heart: and support.
Install with npm:
``sh`
$ npm install --save snapdragon-util
`js`
var util = require('snapdragon-util');
Returns true if the given value is a node.
Params
* node {Object}: Instance of snapdragon-nodereturns
* {Boolean}
Example
`js`
var Node = require('snapdragon-node');
var node = new Node({type: 'foo'});
console.log(utils.isNode(node)); //=> true
console.log(utils.isNode({})); //=> false
Emit an empty string for the given node.
Params
* node {Object}: Instance of snapdragon-nodereturns
* {undefined}
Example
`js`
// do nothing for beginning-of-string
snapdragon.compiler.set('bos', utils.noop);
Returns node.value or node.val.
Params
* node {Object}: Instance of snapdragon-nodereturns
* {String}: returns
Example
`js`
const star = new Node({type: 'star', value: '*'});
const slash = new Node({type: 'slash', val: '/'});
console.log(utils.value(star)) //=> '*'
console.log(utils.value(slash)) //=> '/'
Append node.value to compiler.output.
Params
* node {Object}: Instance of snapdragon-nodereturns
* {undefined}
Example
`js`
snapdragon.compiler.set('text', utils.identity);
Previously named .emit, this method appends the given value to compiler.output for the given node. Useful when you know what value should be appended advance, regardless of the actual value of node.value.
Params
* node {Object}: Instance of snapdragon-nodereturns
* {Function}: Returns a compiler middleware function.
Example
`js`
snapdragon.compiler
.set('i', function(node) {
this.mapVisit(node);
})
.set('i.open', utils.append(''))
.set('i.close', utils.append(''))
Used in compiler middleware, this onverts an AST node into an empty text node and deletes node.nodes if it exists. The advantage of this method is that, as opposed to completely removing the node, indices will not need to be re-calculated in sibling nodes, and nothing is appended to the output.
Params
* node {Object}: Instance of snapdragon-nodenodes
* {Array}: Optionally pass a new nodes value, to replace the existing node.nodes array.
Example
`jsnode.nodes
utils.toNoop(node);
// convert to the given value instead of deleting it`
utils.toNoop(node, []);
Visit node with the given fn. The built-in .visit method in snapdragon automatically calls registered compilers, this allows you to pass a visitor function.
Params
* node {Object}: Instance of snapdragon-nodefn
* {Function}returns
* {Object}: returns the node after recursively visiting all child nodes.
Example
`js`
snapdragon.compiler.set('i', function(node) {
utils.visit(node, function(childNode) {
// do stuff with "childNode"
return childNode;
});
});
Map visit the given fn over node.nodes. This is called by visit, use this method if you do not want fn to be called on the first node.
Params
* node {Object}: Instance of snapdragon-nodeoptions
* {Object}fn
* {Function}returns
* {Object}: returns the node
Example
`js`
snapdragon.compiler.set('i', function(node) {
utils.mapVisit(node, function(childNode) {
// do stuff with "childNode"
return childNode;
});
});
Unshift an *.open node onto node.nodes.
Params
* node {Object}: Instance of snapdragon-nodeNode
* {Function}: (required) Node constructor function from snapdragon-node.filter
* {Function}: Optionaly specify a filter function to exclude the node.returns
* {Object}: Returns the created opening node.
Example
`js
var Node = require('snapdragon-node');
snapdragon.parser.set('brace', function(node) {
var match = this.match(/^{/);
if (match) {
var parent = new Node({type: 'brace'});
utils.addOpen(parent, Node);
console.log(parent.nodes[0]):
// { type: 'brace.open', value: '' };
// push the parent "brace" node onto the stack
this.push(parent);
// return the parent node, so it's also added to the AST
return brace;
}
});
`
Push a *.close node onto node.nodes.
Params
* node {Object}: Instance of snapdragon-nodeNode
* {Function}: (required) Node constructor function from snapdragon-node.filter
* {Function}: Optionaly specify a filter function to exclude the node.returns
* {Object}: Returns the created closing node.
Example
`js
var Node = require('snapdragon-node');
snapdragon.parser.set('brace', function(node) {
var match = this.match(/^}/);
if (match) {
var parent = this.parent();
if (parent.type !== 'brace') {
throw new Error('missing opening: ' + '}');
}
utils.addClose(parent, Node);
console.log(parent.nodes[parent.nodes.length - 1]):
// { type: 'brace.close', value: '' };
// no need to return a node, since the parent
// was already added to the AST
return;
}
});
`
Wraps the given node with .open and .close nodes.
Params
* node {Object}: Instance of snapdragon-nodeNode
* {Function}: (required) Node constructor function from snapdragon-node.filter
* {Function}: Optionaly specify a filter function to exclude the node.returns
* {Object}: Returns the node
Push the given node onto parent.nodes, and set parent as node.parent.
Params
* parent {Object}
* node {Object}: Instance of snapdragon-node
* returns {Object}: Returns the child node
Example
``js`
var parent = new Node({type: 'foo'});
var node = new Node({type: 'bar'});
utils.pushNode(parent, node);
console.log(parent.nodes[0].type) // 'bar'
console.log(node.parent.type) // 'foo'
Unshift node onto parent.nodes, and set parent as node.parent.
Params
* parent {Object}
* node {Object}: Instance of snapdragon-node
* returns {undefined}
Example
``js`
var parent = new Node({type: 'foo'});
var node = new Node({type: 'bar'});
utils.unshiftNode(parent, node);
console.log(parent.nodes[0].type) // 'bar'
console.log(node.parent.type) // 'foo'
Pop the last node off of parent.nodes. The advantage of using this method is that it checks for node.nodes and works with any version of snapdragon-node.
Params
* parent {Object}node
* {Object}: Instance of snapdragon-nodereturns
* {Number|Undefined}: Returns the length of node.nodes or undefined.
Example
`js`
var parent = new Node({type: 'foo'});
utils.pushNode(parent, new Node({type: 'foo'}));
utils.pushNode(parent, new Node({type: 'bar'}));
utils.pushNode(parent, new Node({type: 'baz'}));
console.log(parent.nodes.length); //=> 3
utils.popNode(parent);
console.log(parent.nodes.length); //=> 2
Shift the first node off of parent.nodes. The advantage of using this method is that it checks for node.nodes and works with any version of snapdragon-node.
Params
* parent {Object}node
* {Object}: Instance of snapdragon-nodereturns
* {Number|Undefined}: Returns the length of node.nodes or undefined.
Example
`js`
var parent = new Node({type: 'foo'});
utils.pushNode(parent, new Node({type: 'foo'}));
utils.pushNode(parent, new Node({type: 'bar'}));
utils.pushNode(parent, new Node({type: 'baz'}));
console.log(parent.nodes.length); //=> 3
utils.shiftNode(parent);
console.log(parent.nodes.length); //=> 2
Remove the specified node from parent.nodes.
Params
* parent {Object}node
* {Object}: Instance of snapdragon-nodereturns
* {Object|undefined}: Returns the removed node, if successful, or undefined if it does not exist on parent.nodes.
Example
`js`
var parent = new Node({type: 'abc'});
var foo = new Node({type: 'foo'});
utils.pushNode(parent, foo);
utils.pushNode(parent, new Node({type: 'bar'}));
utils.pushNode(parent, new Node({type: 'baz'}));
console.log(parent.nodes.length); //=> 3
utils.removeNode(parent, foo);
console.log(parent.nodes.length); //=> 2
Returns true if node.type matches the given type. Throws a TypeError if node is not an instance of Node.
Params
* node {Object}: Instance of snapdragon-nodetype
* {String}returns
* {Boolean}
Example
`js`
var Node = require('snapdragon-node');
var node = new Node({type: 'foo'});
console.log(utils.isType(node, 'foo')); // false
console.log(utils.isType(node, 'bar')); // true
Returns true if the given node has the given type in node.nodes. Throws a TypeError if node is not an instance of Node.
Params
* node {Object}: Instance of snapdragon-nodetype
* {String}returns
* {Boolean}
Example
`js`
var Node = require('snapdragon-node');
var node = new Node({
type: 'foo',
nodes: [
new Node({type: 'bar'}),
new Node({type: 'baz'})
]
});
console.log(utils.hasType(node, 'xyz')); // false
console.log(utils.hasType(node, 'baz')); // true
Returns the first node from node.nodes of the given type
Params
* nodes {Array}type
* {String}returns
* {Object|undefined}: Returns the first matching node or undefined.
Example
`js
var node = new Node({
type: 'foo',
nodes: [
new Node({type: 'text', value: 'abc'}),
new Node({type: 'text', value: 'xyz'})
]
});
var textNode = utils.firstOfType(node.nodes, 'text');
console.log(textNode.value);
//=> 'abc'
`
Returns the node at the specified index, or the first node of the given type from node.nodes.
Params
* nodes {Array}type
* {String|Number}: Node type or index.returns
* {Object}: Returns a node or undefined.
Example
`js
var node = new Node({
type: 'foo',
nodes: [
new Node({type: 'text', value: 'abc'}),
new Node({type: 'text', value: 'xyz'})
]
});
var nodeOne = utils.findNode(node.nodes, 'text');
console.log(nodeOne.value);
//=> 'abc'
var nodeTwo = utils.findNode(node.nodes, 1);
console.log(nodeTwo.value);
//=> 'xyz'
`
Returns true if the given node is an "*.open" node.
Params
* node {Object}: Instance of snapdragon-nodereturns
* {Boolean}
Example
`js
var Node = require('snapdragon-node');
var brace = new Node({type: 'brace'});
var open = new Node({type: 'brace.open'});
var close = new Node({type: 'brace.close'});
console.log(utils.isOpen(brace)); // false
console.log(utils.isOpen(open)); // true
console.log(utils.isOpen(close)); // false
`
Returns true if the given node is a "*.close" node.
Params
* node {Object}: Instance of snapdragon-nodereturns
* {Boolean}
Example
`js
var Node = require('snapdragon-node');
var brace = new Node({type: 'brace'});
var open = new Node({type: 'brace.open'});
var close = new Node({type: 'brace.close'});
console.log(utils.isClose(brace)); // false
console.log(utils.isClose(open)); // false
console.log(utils.isClose(close)); // true
`
Returns true if the given node is an "*.open" node.
Params
* node {Object}: Instance of snapdragon-nodereturns
* {Boolean}
Example
`js
var Node = require('snapdragon-node');
var brace = new Node({type: 'brace'});
var open = new Node({type: 'brace.open', value: '{'});
var inner = new Node({type: 'text', value: 'a,b,c'});
var close = new Node({type: 'brace.close', value: '}'});
brace.push(open);
brace.push(inner);
brace.push(close);
console.log(utils.isBlock(brace)); // true
`
Returns true if parent.nodes has the given node.
Params
* type {String}returns
* {Boolean}
Example
`js`
const foo = new Node({type: 'foo'});
const bar = new Node({type: 'bar'});
cosole.log(util.hasNode(foo, bar)); // false
foo.push(bar);
cosole.log(util.hasNode(foo, bar)); // true
Returns true if node.nodes has an .open node
Params
* node {Object}: Instance of snapdragon-nodereturns
* {Boolean}
Example
`js
var Node = require('snapdragon-node');
var brace = new Node({
type: 'brace',
nodes: []
});
var open = new Node({type: 'brace.open'});
console.log(utils.hasOpen(brace)); // false
brace.pushNode(open);
console.log(utils.hasOpen(brace)); // true
`
Returns true if node.nodes has a .close node
Params
* node {Object}: Instance of snapdragon-nodereturns
* {Boolean}
Example
`js
var Node = require('snapdragon-node');
var brace = new Node({
type: 'brace',
nodes: []
});
var close = new Node({type: 'brace.close'});
console.log(utils.hasClose(brace)); // false
brace.pushNode(close);
console.log(utils.hasClose(brace)); // true
`
Returns true if node.nodes has both .open and .close nodes
Params
* node {Object}: Instance of snapdragon-nodereturns
* {Boolean}
Example
`js
var Node = require('snapdragon-node');
var brace = new Node({
type: 'brace',
nodes: []
});
var open = new Node({type: 'brace.open'});
var close = new Node({type: 'brace.close'});
console.log(utils.hasOpen(brace)); // false
console.log(utils.hasClose(brace)); // false
brace.pushNode(open);
brace.pushNode(close);
console.log(utils.hasOpen(brace)); // true
console.log(utils.hasClose(brace)); // true
`
Push the given node onto the state.inside array for the given type. This array is used as a specialized "stack" for only the given node.type.
Params
* state {Object}: The compiler.state object or custom state object.node
* {Object}: Instance of snapdragon-nodereturns
* {Array}: Returns the state.inside stack for the given type.
Example
`js`
var state = { inside: {}};
var node = new Node({type: 'brace'});
utils.addType(state, node);
console.log(state.inside);
//=> { brace: [{type: 'brace'}] }
Remove the given node from the state.inside array for the given type. This array is used as a specialized "stack" for only the given node.type.
Params
* state {Object}: The compiler.state object or custom state object.node
* {Object}: Instance of snapdragon-nodereturns
* {Array}: Returns the state.inside stack for the given type.
Example
`js`
var state = { inside: {}};
var node = new Node({type: 'brace'});
utils.addType(state, node);
console.log(state.inside);
//=> { brace: [{type: 'brace'}] }
utils.removeType(state, node);
//=> { brace: [] }
Returns true if node.value is an empty string, or node.nodes does not contain any non-empty text nodes.
Params
* node {Object}: Instance of snapdragon-nodefn
* {Function}returns
* {Boolean}
Example
`js`
var node = new Node({type: 'text'});
utils.isEmpty(node); //=> true
node.value = 'foo';
utils.isEmpty(node); //=> false
Returns true if the state.inside stack for the given type exists and has one or more nodes on it.
Params
* state {Object}type
* {String}returns
* {Boolean}
Example
`js`
var state = { inside: {}};
var node = new Node({type: 'brace'});
console.log(utils.isInsideType(state, 'brace')); //=> false
utils.addType(state, node);
console.log(utils.isInsideType(state, 'brace')); //=> true
utils.removeType(state, node);
console.log(utils.isInsideType(state, 'brace')); //=> false
Returns true if node is either a child or grand-child of the given type, or state.inside[type] is a non-empty array.
Params
* state {Object}: Either the compiler.state object, if it exists, or a user-supplied state object.node
* {Object}: Instance of snapdragon-nodetype
* {String}: The node.type to check for.returns
* {Boolean}
Example
`js`
var state = { inside: {}};
var node = new Node({type: 'brace'});
var open = new Node({type: 'brace.open'});
console.log(utils.isInside(state, open, 'brace')); //=> false
utils.pushNode(node, open);
console.log(utils.isInside(state, open, 'brace')); //=> true
Get the last n element from the given array. Used for gettingnode.nodes.
a node from
Params
* array {Array}n
* {Number}returns
* {undefined}
Cast the given value to an array.
Params
* value {any}returns
* {Array}
Example
`js`
console.log(utils.arrayify(''));
//=> []
console.log(utils.arrayify('foo'));
//=> ['foo']
console.log(utils.arrayify(['foo']));
//=> ['foo']
Convert the given value to a string by joining with ,. Useful
for creating a cheerio/CSS/DOM-style selector from a list of strings.
Params
* value {any}returns
* {Array}
Ensure that the given value is a string and call .trim() on it,
or return an empty string.
Params
* str {String}returns
* {String}
Contributing
Pull requests and stars are always welcome. For bugs and feature requests, please create an issue.
Please read the contributing guide for advice on opening issues, pull requests, and coding standards.
Running Tests
Running and reviewing unit tests is a great way to get familiarized with a library and its API. You can install dependencies and run tests with the following command:
`sh`
$ npm install && npm test
Building docs
_(This project's readme.md is generated by verb, please don't edit the readme directly. Any changes to the readme must be made in the .verb.md readme template.)_
To generate the readme, run the following command:
`sh``
$ npm install -g verbose/verb#dev verb-generate-readme && verb
You might also be interested in these projects:
* snapdragon-node: Snapdragon utility for creating a new AST node in custom code, such as plugins. | homepage
* snapdragon-position: Snapdragon util and plugin for patching the position on an AST node. | homepage
* snapdragon-token: Create a snapdragon token. Used by the snapdragon lexer, but can also be used by… more | homepage
| Commits | Contributor |
| --- | --- |
| 43 | jonschlinkert |
| 2 | realityking |
Jon Schlinkert
* linkedin/in/jonschlinkert
* github/jonschlinkert
* twitter/jonschlinkert
Copyright © 2018, Jon Schlinkert.
Released under the MIT License.
*
_This file was generated by verb-generate-readme, v0.6.0, on January 11, 2018._