ytaki0801

# Wolfram's 2-state 3-symbol Turing Machine

from time import sleep

delta = {1: {0: (1,  1, 2), 1: (2, -1, 1), 2: (1, -1, 1)},
         2: {0: (2, -1, 1), 1: (2,  1, 2), 2: (0,  1, 1)}}
ds = {0: ' ', 1: '.', 2: '*'}

tlen = 80
tape, head, state = [0] * tlen, int(tlen / 2) - 9, 1

ytaki0801

# Wolfram's 2-state 3-symbol Turing Machine as an Universal TM
# with Turtle Graphics

from time import sleep
from turtle import fd, rt, lt, setpos, pu, pd

pu(); setpos(-300, 300); pd(); sleep(5)

delta = {1: {0: (1,  1, 2), 1: (2, -1, 1), 2: (1, -1, 1)},
         2: {0: (2, -1, 1), 1: (2,  1, 2), 2: (0,  1, 1)}}

ytaki0801

####
#### letLISP-REPL.py:
#### A Pure LISP Interpreter
#### with dynamic-scope named-let
#### in pseudocode-style Python 3
####
#### (C) 2022 TAKIZAWA Yozo
#### This code is licensed under CC0,
#### Creative Commons 0 as Public Domain
####

ytaki0801

####
#### letLISP.py:
#### A Pure LISP Interpreter
#### with dynamic-scope named-let
#### in pseudocode-style Python 3
####
#### (C) 2022 TAKIZAWA Yozo
#### This code is licensed under CC0.
#### https://creativecommons.org/publicdomain/zero/1.0/
####

ytaki0801

####
#### ev.py: A Pure LISP Interpreter
#### in Pseudocode-style Python 3
####
#### (C) 2022 TAKIZAWA Yozo
#### This code is licensed under CC0.
#### https://creativecommons.org/publicdomain/zero/1.0/
####

#### <examples>

ytaki0801

#!/bin/sh

# One token input function with look-ahead caching
stty -icanon
LF="$(printf \\012)"
get_c1 () {
  case "$LH" in ("") GC1R=$(dd bs=1 count=1 2>/dev/null)
  ;;(*) GC1R="$LH"; LH="" ;;esac
}
skip_spaces () {

ytaki0801

from sys import stdin

LH = False
def get_token():
    def put_c1(x): global LH; LH = x
    def null_c1(): global LH; LH = False
    def get_c1():
        if not LH:
            try: return stdin.read(1)
            except EOFError: pass

ytaki0801

(define *lh* #f)
(define (get-token)
  (define (put-c1 x) (set! *lh* x))
  (define (null-c1) (set! *lh* #f))
  (define (get-c1) (if *lh* (let ((lh *lh*)) (null-c1) lh) (read-char)))
  (define (tstring t) (list->string (reverse t)))
  (define (skip-spaces)
    (do ((c (get-c1) (get-c1)))
        ((not (member c (string->list " \n\r"))) (put-c1 c))))
  (let loop ((c (get-c1)) (t '()))

ytaki0801

(define *lh* #f)
(define (get-token)
  (define (put-c1 x) (set! *lh* x))
  (define (null-c1) (set! *lh* #f))
  (define (get-c1) (if *lh* (let ((lh *lh*)) (null-c1) lh) (read-char)))
  (define (tstring t) (list->string (reverse t)))
  (define (skip-spaces)
    (do ((c (get-c1) (get-c1)))
        ((not (member c (string->list " \n\r"))) (put-c1 c))))
  (let loop ((c (get-c1)) (t '()))

ytaki0801

%{
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

extern int yylex(void);
int yyerror(const char *s) { printf("%s\n", s); return 0; }

int node[4096]; int nnum = 1;