This project is a toy project to implement a simple top down parser with a custom syntax. The algorithm is inspired by the structure of EBNF itself, meaning in order to parse a string successfully the following things are needed:
- Handwritten parsing routines for terminal symbols (i.e. digits, letters, etc.).
- For every symbol that is not purly non-terminal, parsing routines for the terminal parts have to be written.
- All non-terminal symbols can be combined using the
all_of,one_of,optionalandrepeatedoperators, which rougly correspond to the operators found in EBNF.
The following features are planned for certain versions:
-
v0.1
Parsing of simple arithmetic expressions as described indoc/v0.1.ebnf. The goal here is to setup the needed helper functions, unit tests and get used to everything. -
v0.2
Before progressing to the code generation part, the grammer is extended to support compound (parenthsized) expressions and simple builtin function calls (i.e.sin(),cos(),tan()). If there are any major flaws with the current approach those should be detected in this stage. -
v0.3
For this version the error reporting should be improved as it is kind of non-existent by now. The report should consist of the line and column number of the error encountered as well as a sensible error message. -
v0.4
By now a simple code generator should be implemented for the given syntax. Most probably the output will be in C++ or any other high level language. Code generators for assembler or LLVM-IL may be added later on.