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Diffstat (limited to 'source/state/definition.d')
-rw-r--r-- | source/state/definition.d | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/source/state/definition.d b/source/state/definition.d new file mode 100644 index 0000000..ab100d5 --- /dev/null +++ b/source/state/definition.d @@ -0,0 +1,84 @@ +module state.definition; + +import std.string; +import std.variant; +import std.typecons; + +import std.container : DList; + +import state.stack; + +alias Words = Stack!Token[string]; + +Words words; + +bool handle(Token token) { + return token.visit!( + (int value) => handle(value), + (bool value) => handle(value), + (string word ) => handle(word) + ); +} + +Stack!Token get(string word) { + if ( word in words ) { + return words[word].dup; + } else { + return Stack!Token(Token(word)); + } +} + +private { + +Nullable!(DList!Token) definition; + +void register(DList!Token definition) { + string wordToBeDefined; + + definition.front.visit!( + (int value) => wordToBeDefined = "", + (bool value) => wordToBeDefined = "", + (string name ) => wordToBeDefined = name + ); + + if ( wordToBeDefined == "" ) { + throw new Exception("words may not be numeric or boolean"); + } + + definition.removeFront; + words[wordToBeDefined] = Stack!Token(definition[]); +} + +template handle(T) +if ( is(T == int) || is(T == bool) ) { + bool handle(T value) { + if ( definition.isNull ) { + return false; + } else { + definition.insertBack(Token(value)); + return true; + } + } +} + +bool handle(string word) { + if ( definition.isNull ) { + if ( word == "ยง" ) { + definition = DList!Token(); + return true; + } else { + return false; + } + } else { + if ( word == ";" ) { + register(definition); + definition.nullify; + } else { + definition.insertBack(Token(word)); + } + + return true; + } +} + +} |