Parses tokens from a CLI.
- Number parser
3.14, 33e+2, 1.1e-3, -13.22 etc
- Expression parser
( 5 - 34 * (23 / 5))
Requires gcc/clang (C++17 or above). Will possibly switch to C++20 later.
Needs cmake to compile the code.
cd token-parser
cmake .
cmake --build .
bld/main
It will bring the parser prompt where it can be tested
=token-parser v0.0.1=
>>> ( 4 - ( 9 * 4 ))
Expression: ( OPRAND(4) OPERATOR(-) ( OPRAND(9) OPERATOR(*) OPRAND(4) ) )
>>> 45.3e10
Result: 4.53e+11
Integer: 45 Fraction: 0.3 Exponent: 1e+10
>>>
These are first benchmark results. Parser can be improved and this can be optimised. There is a coversion error because the coversion doesn't do caveats possibly in IEEE754 double precision floating point standard. The error is minimal and should have same precision as double (precise upto 15 decimal places). Our parser is 10x slower on average.
String Representation std::stod Value NumberParser Value Conversion Error
1 875ns 1 2208ns 1 0
-9223372036854775808 1666ns -9.22337e+18 6417ns -9.22337e+18 0
9223372036854775807 667ns 9.22337e+18 5333ns 9.22337e+18 0
1.0 125ns 1 2292ns 1 0
1e1 125ns 10 3167ns 10 0
1.23456 167ns 1.23456 3542ns 1.23456 0
2.22507e-306 2584ns 2.22507e-306 7750ns 2.22507e-306 4.74303e-321
1e-307 1000ns 1e-307 5833ns 1e-307 2.17389e-322
1.7976931348623157E+307 1333ns 1.79769e+307 8917ns 1.79769e+307 0
Custom parser is 10.7652x slower than standard parser
- Parser Additions
- Usage Examples
- Parser Benchmarks
- Test infrastructure
- Expression Solver