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Report 2002-11-17


LanguageGame was now developed simple prototype. Now, I can describe some aspect bellow.

The omission of a function

The goal of this project is that I develop a parser generator with GUI and application used the parser. Because espacialy importance is user interface, I cut off some function of parser generator engine. I will give an outline of that abbreviation and feature.

The omission of scanner

Generally, parser generater is combined with scanner and parser. In this project, I determined scanner is omitted. Now I use the scanner of Sueak itself as scanner of LanguageGame. Therefore, tokens which is recognized LanguageGame are same tokens of Squeak.

Simply BNF

In this system, BNF notation is used but you can't use parallel expression with '|', and it doesn't recognize difference between symbol with word, then grammar

pair : animal animal
animal : Tom
animal : Jerry

matches not only 'Tom Jerry' but also 'Tom animal'

Simply parser

LanguageGame supports the generation of buttom-up parser. But not using LR-table, it uses a poor rule that matches first pattern of right side simbols of stack. This strategy is not good for performance and strict, but enough as my first simple step.

Action with expressin of Smalltalk

Parsed object is evaluted with 'action'. This action is written in the expression of block context of Smalltalk. Each node have semantic value which is maked by evaluted the acton. Additionaly, action can deal with external object like Morph as global variable using bindingOf mechanism.

Graphical representation

After parse, a parse tree is shown to screen by subclass of GTile. You can show the tree different ways to implement subclass of GTile.

see ToDo
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