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Diffstat (limited to 'src/sdlang/symbol.d')
-rw-r--r-- | src/sdlang/symbol.d | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/src/sdlang/symbol.d b/src/sdlang/symbol.d new file mode 100644 index 0000000..14a74a7 --- /dev/null +++ b/src/sdlang/symbol.d @@ -0,0 +1,61 @@ +// SDLang-D +// Written in the D programming language. + +module sdlang.symbol; + +import std.algorithm; + +static immutable validSymbolNames = [ + "Error", + "EOF", + "EOL", + + ":", + "=", + "{", + "}", + + "Ident", + "Value", +]; + +/// Use this to create a Symbol. Ex: symbol!"Value" or symbol!"=" +/// Invalid names (such as symbol!"FooBar") are rejected at compile-time. +template symbol(string name) +{ + static assert(validSymbolNames.find(name), "Invalid Symbol: '"~name~"'"); + immutable symbol = _symbol(name); +} + +private Symbol _symbol(string name) +{ + return Symbol(name); +} + +/// Symbol is essentially the "type" of a Token. +/// Token is like an instance of a Symbol. +/// +/// This only represents terminals. Nonterminal tokens aren't +/// constructed since the AST is built directly during parsing. +/// +/// You can't create a Symbol directly. Instead, use the 'symbol' +/// template. +struct Symbol +{ + private string _name; + @property string name() + { + return _name; + } + + @disable this(); + private this(string name) + { + this._name = name; + } + + string toString() + { + return _name; + } +} |