Implement a concatenative language

Description

• Influenced by:

  • Tsoding Porth
  • Forth
  • Uxn

• run: v run . -c -i examples/arithmetic.vorth

  • -c is to compile the code. That means you can run the test: ./examples/arithmetic

• or with debug logs: v run . -c -i -d 5 examples/arithmetic.vorth

• The language is case insensitive

List of operators

Operators	stack state	Description
+	a b -- (a + b)
*	a b -- (a * b)
-	a b -- (a - b)
=	a b -- Flag	True if a == b, False otherwise
!=	a b -- Flag	True if a != b, False otherwise
<	a b -- Flag	True if a < b, False otherwise
>	a b -- Flag	True if a > b, False otherwise
.	a --
divmod	a b -- (a / b) (a % b)
dup	a -- a a
integer	-- a	integer is i64
load	a -- mem[a]	Put on the stack the value at mem[a]
not	Flag -- not Flag	Inverse True and False
store	v a --	Store v in mem[a]
swap	a b -- b a

Operators	stack state	Description
if	flag --	If True then it continues, otherwise
else	--	it jumps to execute the then. If then
end	--	is reached it jumps to end.

Operators	stack state	Description
while	--	If True then do continues, otherwise
do	flag --	it jumps right after the done. Done
done	--	jumps to while.

Example

~/devel/vlang-forth master*
❯ v run . -c -i -d 5 examples/arithmetic.vorth
log level is set to 5
2024-03-08 22:05:41.692216 [DEBUG] ==== LOADING PROGRAM
2024-03-08 22:05:41.692242 [DEBUG] // arithmetic.vorth
2024-03-08 22:05:41.692245 [DEBUG]
2024-03-08 22:05:41.692249 [DEBUG] 12 30 + .      // should print 42
2024-03-08 22:05:41.692251 [DEBUG] 6 9 - .        // should print -3
2024-03-08 22:05:41.692254 [DEBUG] 12 dup + .     // should print 24
2024-03-08 22:05:41.692256 [DEBUG] 15 10 - .      // should print 5
2024-03-08 22:05:41.692258 [DEBUG] 15 10 swap - . // should print -5
2024-03-08 22:05:41.692261 [DEBUG] 5 dup mul .    // it is the square operation, 25
2024-03-08 22:05:41.692264 [DEBUG] 8 0 3 - * .    // should print -24
2024-03-08 22:05:41.692267 [DEBUG] 117 17 divmod . . // 117 17 -- 6 15
2024-03-08 22:05:41.692270 [DEBUG]                   // where 6 is the quotient and 15 the reminder
2024-03-08 22:05:41.692275 [DEBUG]                   // So should print 15 6
2024-03-08 22:05:41.692278 [DEBUG]
2024-03-08 22:05:41.692287 [DEBUG] ==== PROGRAM LOADED
42
-3
24
5
-5
25
-24
15
6

~/devel/vlang-forth master*
❯ ./examples/arithmetic
42
-3
24
5
-5
25
-24
15
6

• others examples are not all ready. Check comments in the files.

Goals

• start with simples instructions to do arithmetic
• compile code
• update lexer to recognize true, false, eq, neq
• implement new tokens ^^
• allow comments
• add conditionnal if
• add while loop
• manage memory
• what else to be Turing complete?
  • Run Game Of Life to prove the Turing completeness

Changelog

2024-03-16

• Implement Load and Store in memory
  • memory is 1024 bytes

2024-03-13

• Conditionnal and loop are now compiled

2024-03-12

• Introduce the interpreted version of the while loop
  • all tests are now running in interpreted mode
  • blocks are not yet available in compiled mode

2024-03-10

• Adding conditionnal block if ... else ... end
• Report filename:line:col:<error msg> in case of error

2024-03-07

• Add Eq, Neq, Dup, Swap, Mul, Divmod, Gth, Lth, Not

2024-03-06

• Add False and True
• Update lexer to recognize identifiers
• Generate code for +, -, ..
  • So we can print result of addition and substraction
• Compile an hello world program

2024-03-05

• Add a minimal help
• Read the code from arithmetic.vorth and print the result
• Replace Pop by Dot to be more like Forth and translate string to ops
• Add operations: Add, Sub, Push and Pop
• First implement a stack in V