tinyTcl is a small header-only Tcl interpreter forked from https://github.com/zserge/partcl and optimized to run on the ESP32.
# any text you like after comment
subst arg
set var ?val?
while cond loop
if cond branch ?cond? ?branch? ?other?
proc name args body
return ?val?
break
continue+ num1 num2
- num1 num2
* num1 num2
/ num1 num2
< num1 num2
> num1 num2
<= num1 num2
>= num1 num2
== num1 num2
!= num1 num2
# these commands only take 2 arguments for nowopen stream ?details?
# serial ports are setup as /dev/serial0.../dev/serial3 -- take baud rate
# SPI port is setup as /dev/spi -- takes nothing
# other files on SD card -- take "r" for read and "w" for write
puts ?-nonewline? ?stream? string
# if no stream specified uses /dev/serial (which is default serial port)
read stream ?amount?
# read ALL available bytes from specified stream
# for SPI available is unknown, so amount is required
close stream
# closing a serial port is a noop# check arduino core files for numbering of analog pins
pin mode -i|-o|-iu|-id pinnum
# sets pin mode: input, output, input-pullup, input-pulldown (if supported)
pin read -a|-d|-t pinnum
# reads pin value: analog, digital, touch (if supported)
pin write -a|-d pinnum value
# writes value to pin: analog or digitalFrom an SD card:
#include <SD.h>
#include "tinytcl.h"
struct tcl tcl;
void setup() {
// other setup code
SD.begin();
File f = SD.open("main.tcl");
int a = f.available();
tcl_value_t *s = malloc(a);
f.readBytes(s, a);
tcl_init(&tcl);
tcl_result_t r = tcl_eval(&tcl, s, a);
// now do something with tcl.result and r
}Interactive Serial REPL:
#include <stdlib.h>
#include "tinytcl.h"
#define CHUNK 64
void loop() {
struct tcl tcl;
int buflen = CHUNK;
char *buf = malloc(buflen);
int i = 0;
tcl_init(&tcl);
while (true) {
char inp = Serial.read();
if (i > buflen - 1) buf = realloc(buf, buflen += CHUNK);
if (inp == 0 || inp == -1) continue;
buf[i++] = inp;
tcl_each(buf, i, true) {
if (p.token == TOK_ERROR && (p.to - buf) != i) {
memset(buf, 0, buflen);
i = 0;
Serial.println("Syntax error");
break;
} else if (p.token == TOK_COMMAND && *(p.from) != '\0') {
tcl_result_t r = tcl_eval(&tcl, buf, strlen(buf));
if (r != TCL_ERROR) {
Serial.print("result> ");
} else {
Serial.print("?! ");
}
Serial.println(tcl_string(tcl.result));
memset(buf, 0, buflen);
i = 0;
break;
}
}
}
}