parser.js

parser.js

Sets up the parser generated by canopy to use the Node subclasses in the generated tree. This is all a bit of a hack that is dependent on how canopy creates nodes in its parse tree.

import parser from './grammar.peg';

import Node from './node.js';
import Root from './root.js';
import Regexp from './regexp.js';
import Match from './match.js';
import MatchFragment from './match_fragment.js';
import Anchor from './anchor.js';
import Subexp from './subexp.js';
import Charset from './charset.js';
import CharsetEscape from './charset_escape.js';
import CharsetRange from './charset_range.js';
import Literal from './literal.js';
import Escape from './escape.js';
import AnyCharacter from './any_character.js';
import Repeat from './repeat.js';
import RepeatAny from './repeat_any.js';
import RepeatOptional from './repeat_optional.js';
import RepeatRequired from './repeat_required.js';
import RepeatSpec from './repeat_spec.js';

¶

Canopy creates an instance of SyntaxNode for each element in the tree, then adds any necessary fields to that instance. In this case, we’re replacing the default class with the Node class.
```
parser.Parser.SyntaxNode      = Node;
```

Once the SyntaxNode instance is created, the specific node type object is overlayed onto it. This causes the module attribute on the Node to be set, which updates the Node instance into the more specific “subclass” that is used for rendering.

parser.Parser.Root            = { module: Root };
parser.Parser.Regexp          = { module: Regexp };
parser.Parser.Match           = { module: Match };
parser.Parser.MatchFragment   = { module: MatchFragment };
parser.Parser.Anchor          = { module: Anchor };
parser.Parser.Subexp          = { module: Subexp };
parser.Parser.Charset         = { module: Charset };
parser.Parser.CharsetEscape   = { module: CharsetEscape };
parser.Parser.CharsetRange    = { module: CharsetRange };
parser.Parser.Literal         = { module: Literal };
parser.Parser.Escape          = { module: Escape };
parser.Parser.AnyCharacter    = { module: AnyCharacter };
parser.Parser.Repeat          = { module: Repeat };
parser.Parser.RepeatAny       = { module: RepeatAny };
parser.Parser.RepeatOptional  = { module: RepeatOptional };
parser.Parser.RepeatRequired  = { module: RepeatRequired };
parser.Parser.RepeatSpec      = { module: RepeatSpec };

export default parser;