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Parsing System (v0.5)
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GoldieLib OverviewGoldieLib is Goldie's D v2.x API. Using GoldieLib, your D programs can parse text according to any GOLD-compatible grammar and access some of Goldie's other capabilities. ImportingImporting is simple: import goldie.all;Conventions Used By GoldieLibLine and Column NumbersAll line numbers and column numbers are internally stored and treated by the API as zero-indexed and displayed to the user as one-indexed. When Goldie refers to a "column number", it really means "the number of characters (ie, UTF code-points) from the start of the line". This behavior is more reliable and more useful than a true "column number" because:
Tokens, Symbols, and Symbol Types:
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| Word | Symbol | This Symbol's type is SymbolType.Terminal. |
| <Sentence> | Symbol | This Symbol's type is SymbolType.NonTerminal. |
| Hello | Token | This Token's Symbol is Word. |
| world | Token | This Token's Symbol is Word. |
| Hello world | Token | This Token's Symbol is <Sentence>. |
Note that Goldie defines more symbol types than just Terminal and NonTerminal (see the SymbolType documentation). So if you want to check if a Symbol or Token is a SymbolType.NonTerminal do NOT do it by comparing the type with SymbolType.Terminal. Just because something isn't a SymbolType.Terminal does NOT imply that it's a SymbolType.NonTerminal.
Just use null for the subtokens.
Example:
Suppose you have this in your grammar for language "myLang": <Optional Fred> ::= 'fred' |
The nonterminal <Optional Fred> can be created from either the text fred or from nothing at all. To check if a token matches the first case, ie. the fred rule, you use this: // static-style: if( auto typedTok = cast(Token_myLang!("<Optional Fred>", "fred"))token ) { // use typedTok } // dynamic-style: if( token.matches("<Optional Fred>", "fred") ) { // use token }
To check for the empty rule, you just use null: // static-style: if( auto typedTok = cast(Token_myLang!("<Optional Fred>", null))token ) { // use typedTok } // dynamic-style: if( token.matches("<Optional Fred>", null) ) { // use token }
For simple examples of how to use GoldieLib, see the GoldieLib Sample Apps.