Nasal-- Interpreter

Nasal

Nasal is a script language that used in FlightGear.

There is a Nasal console in FlightGear but sometimes it is not so easy for every developer to use.

So this is an interpreter for Nasal written by C++.

The interpreter is still in development.Anyone who interested in this could also join us!

Nasal--

For some reasons i will first try to make a interpreter for nasal--(???)

Maybe.Because i haven't take the lesson of 'principle of compiler'(what a shame...)

Now complete all types

var: int float double std::string char long long int

NasalList: array in nasal []

append

setsize

subvec

pop

sort

NasalHash: Hash in nasal {}

append

delete

contains

keys

Now complete Lexical Analysis!

What it looks like?

( Identifier | engineTimer )

( Operator | . )

( Identifier | start )

( Operator | ( )

( Operator | ) )

( Operator | ; )

( ReserveWord | print )

( Operator | ( )

( String | "Engine started" )

( Operator | ) )

( Operator | ; )

( Operator | } )

( ReserveWord | var )

( Identifier | stopEngine )

( Operator | = )

( ReserveWord | func )

( Operator | ( )

( Operator | ) )

( Operator | { )

( Identifier | props )

( Operator | . )

( Identifier | getNode )

( Operator | ( )

( String | "/" )

( Operator | , )

( Number | 1 )

( Operator | ) )

( Operator | . )

( Identifier | setValue )

( Operator | ( )

( String | "/controls/engines/engine/started" )

( Operator | , )

( Number | 0 )

( Operator | ) )

( Operator | ; )

( Identifier | props )

( Operator | . )

( Identifier | getNode )

( Operator | ( )

( String | "/" )

( Operator | , )

( Number | 1 )

( Operator | ) )

( Operator | . )

( Identifier | setValue )

( Operator | ( )

( String | "/fdm/jsbsim/external_reactions/engine/magnitude" )

( Operator | , )

( Number | 0 )

( Operator | ) )

( Operator | ; )

( Identifier | props )

( Operator | . )

( Identifier | getNode )

( Operator | ( )

( String | "/" )

( Operator | , )

( Number | 1 )

( Operator | ) )

( Operator | . )

( Identifier | setValue )

( Operator | ( )

( String | "/systems/electrical/e-tron/switch/bat-fwd-eng" )

( Operator | , )

( Number | 0 )

( Operator | ) )

( Operator | ; )

( Identifier | props )

( Operator | . )

( Identifier | getNode )

( Operator | ( )

( String | "/" )

( Operator | , )

( Number | 1 )

( Operator | ) )

( Operator | . )

( Identifier | setValue )

( Operator | ( )

( String | "/systems/electrical/e-tron/switch/bat-bwd-eng" )

( Operator | , )

( Number | 0 )

( Operator | ) )

( Operator | ; )

( Identifier | engineTimer )

( Operator | . )

( Identifier | stop )

( Operator | ( )

( Operator | ) )

( Operator | ; )

( ReserveWord | print )

( Operator | ( )

( String | "Engine stopped" )

( Operator | ) )

( Operator | ; )

( Operator | } )

This is what it outputs.

Now with var_stack and function_stack

By printing the two stacks you can see how vars and functions change!

[long long int]a:1

[double]b:3.14

[string]c:"hello world!"

function:swap

function:__main

function:hello

The structure of basical elements is...

class var;

class nasal_hash;//forward declaration

struct nasal_list_unit;

class nasal_list;

struct nasal_hash_unit;

class nasal_hash;

struct token_unit;

struct parameter;

class func;

class var_stack;

var_stack nasal_var_stack;

class func_stack;

func_stack nasal_func_stack;

class token_list;

token_list nasal_lexer;

class parse;

parse nasal_parser;

#include "nasal_lexer.h"

main();