Mini-LISP-interpreter

NCU compiler final project

how to compile this project

method 1 - run make.sh in your ubuntu shell

    ./make.sh

method 2 - run this script of code in your ubuntu shell

    bison -d lisp.y
    flex lisp.l
    gcc -c lisp.tab.c
    gcc -c lex.yy.c
    gcc lex.yy.o lisp.tab.o -lfl

Program Flow Chart

string stream(mini lisp code) -> lex -> token stream -> yacc -> syntax tree -> c code to traverse tree -> symbol table & execute

AST tree node

non-terminal	type	id
number	I
boolean	B
variable	V	variable identifier
exps	E
printnum	P
printbool	p
stmts	T
define	D
num_op	O
logical_op	O
fun_ids	S
fun_exp	F
fun_call	C
params	A
if_exp	G
if_tmp(left child: then_exp, right child: else_exp)	X

symbol_table_node

use symbol table to store those variables declared by user

    struct symbol_table_node{
            char type; // F: function, B: bool, I: integer
            char* id; // id
            int value; // if variable is bool or integer, store value here
            int scope; // work in which scope, e.g. global or only is declared in a function
            struct Node* fun; // if type == function, store the tree node here
    };