Basil

Contents:

Examples

The table below contains links to several example grammars.

Example Grammar Log Simulator

Input Trace Tree

basil rules-01 log-01 input-01 trace-01 tree-01

if else rules-02 log-02 input-02 trace-02 tree-02

expression rules-03 log-03 input-03 trace-03 tree-03

expression with single rules bypassed log-04 trace-04 tree-04

expression with priorities rules-05 log-05 trace-05 tree-05

C++ object declaration (simplified) rules-06 log-06 input-06 trace-06 tree-06

C++ object and function declaration (simplified) rules-07 log-07 input-07 trace-07 tree-07

C++ template-id with type and non-type arguments rules-08 log-08 input-08 trace-08 tree-08

A typical mistake in C++ is to write '>>' instead of '> >' to terminate a nested template-id. basil can recover very easily from such a mistake. For example, let's run basilsim with the log file log-08 and give it the input

# A <B <C>> 
IDENT LT IDENT LT IDENT RSHIFT

The recover strategy 'r:[GT,GT]:RSHIFT' will replace '>>' with '> >'. The recover message is

error.txt:3:1: Syntax error before '{end of file}'
error.txt:2:25: Replacing 'RSHIFT' with 'GT GT'

This would be just one of several recover strategies in a C++ parser.