ESP32forth v7
    & WebSent
       🙜
February 27, 2021

   What's up
with the slides?

PRESENTATION FORMAT
         🙤
 • Takahashi Method
   • Minimalistic presentation style
   • suckless →  sent →  websent
   • 200 LOC

HOW TO USE
    🙤
 • Small 2-6 line header on html
 • Limited customization (color, font)
 • Unicode text as input
 • Show each paragraph fullscreen
 • @image.png for full page images

BUT WHY?
   🙤
 • Focus on content
 • Cut and paste source code
 • Things fit easily
 • ASCII Art & Emojis = easy

trees
🌲🌲🌲🌲
 
evil
🙈🙉🙊
 
♤ spades
♥ hearts
♧ clubs
♦ diamonds

trees
🌲🌲🌲🌲

evil
🙈🙉🙊

♤ spades
♥ hearts
♧ clubs
♦ diamonds

 @eforth.png

 @eforth.png
 <img src="eforth.png">

@eforth.png


Code 🚢
 Tour

ESP32forth
    v7

 Thanks
Dr. Ting!

New Website:
     🙜
esp32forth.appspot.com

Topics
   🙜
 • Vocabularies
 • Block Editor
 • Adding Words
 • Dictionary Pickling
 • Telnet

     🗣️
Vocabularies

Hybrid Vocabularies
   🙜
 • Forth-79 Style Chaining
 • Forth-83+ Style Vocabulary Stack

VOCABULARY ( "name" ) Create a vocabulary
FORTH ( -- ) The FORTH vocabulary
DEFINITIONS ( -- ) Make the context, current
VLIST ( -- ) List the vocabulary
WORDS ( -- ) List the reachable words

TRANSFER ( "name" ) Move a word

ALSO ( -- ) Add vocabulary
ONLY ( -- ) Reset back to Forth only
                    ( Non-standard )
ORDER ( -- ) Print search order

SEALED ( -- ) Make it Forth-83+

🧱 Block
 Editor

SCR ( -- a ) Pointer to last listed block
USE ( "name" -- ) e.g. USE /spiffs/foo
FLUSH ( -- ) Save and empty all buffers
LIST ( n -- ) List a block
LOAD ( n -- ) Evaluate a block
EDITOR ( -- ) Enter editor vocabulary

WIPE ( -- ) Blank out current block
L ( -- ) List the current block
D ( n -- ) Delete a line
E ( n -- ) Erase a line
R ( n "text" -- ) Replace a line
A ( n "text" -- ) Add (insert) a line
P ( -- ) Move to the previous block
N ( -- ) Move to the next block

Live  💥
 Demo...

Adding
💬Words

#define OPCODE_LIST \
  X("0=", ZEQUAL, tos = !tos ? -1 : 0) \
  X("0<", ZLESS, tos = (tos|0) < 0 ? -1 : 0) \
  X("+", PLUS, tos += *sp--) \

Y(MY_WORD123, c_function_to_call()) \

X("myword!", MY_WORD_BANG, c_function_to_call()) \

Y(MY_WORD, PUSH calculate_magic_value()) \

n10 n9 n8 n7 n6 n5 n4 n3 n2 n1 n0 - Access stack as cell_t integer values
             c6 c5 c4 c3 c2 c1 c0 - Access stack as char* values
             b6 b5 b4 b3 b2 b1 b0 - Access stack as uint8_t* byte values
             a6 a5 a4 a3 a2 a1 a0 - Access stack as void* values

void send_message(const char *message, int code);
   🙜
X("send-message", SEND_MESSAGE, \
   send_message(c1, n0); DROPn(2)) \

Y(DECODE, SET decode_func(n0)) \

Y(MY_WORD, cell_t foo = n0; DROP; \
           char *x = c0; DROP; \
           PUSH my_func(foo, x)) \

# define ws0 ((WebServer *) a0)
# define OPTIONAL_WEBSERVER_SUPPORT \
  /* WebServer */ \
  X("WebServer.new", WEBSERVER_NEW, PUSH new WebServer(tos)) \
  X("WebServer.delete", WEBSERVER_DELETE, delete ws0; DROP) \
  X("WebServer.begin", WEBSERVER_BEGIN, ws0->begin(n1); DROPn(2)) \
  X("WebServer.stop", WEBSERVER_STOP, ws0->stop(); DROP) \
  X("WebServer.on", WEBSERVER_ON, InvokeWebServerOn(ws0, c2, n1); DROPn(3)) \
  X("WebServer.hasArg", WEBSERVER_HAS_ARG, n0 = ws0->hasArg(c1); DROP) \

static void InvokeWebServerOn(WebServer *ws, const char *url, cell_t xt) {
  ws->on(url, [xt]() {
    cell_t code[2];
    code[0] = xt;
    code[1] = g_sys.YIELD_XT;
    cell_t stack[16];
    cell_t rstack[16];
    cell_t *rp = rstack;
    *++rp = (cell_t) (stack + 1);
    *++rp = (cell_t) code;
    forth_run(rp);
  });

Dictionary
Picking 🥒

SAVE {filename}
RESTORE {filename}

SAVE-NAME ( a n -- )
RESTORE-NAME ( a n -- )

'COLD ( -- a )
   address of boot word

REMEMBER
STARTUP: {word}

Telnet
  💻

sockets

listen on
 port 23

DEMO
   🐞

QUESTIONS?
          ⚘
   Thank you!