txa

Texo assembly

The assembly language as a token based syntax

It can use any defined VM and stack operations

It may define procedures with this syntax :

define $square
    local @n
    @n @n mul
endef

To interact with the procedure scope use :

• local @IDENTIFIER to pop a value from the stack and store it in scope
• @IDENTIFIER to push a value stored in scope to the stack

While searching for an IDENTIFIER in the scope, if it is not found, the search will continue into the parent's scope until the root scope as been reached

The other VM operations are :

• :IDENTIFIER makes a label to jump to
• BOOL jump :IDENTIFIER jumps to the label if the BOOL is truthy

Comments are done with #[_ to open a comment and _]# to end it where _ is a necessary whitespace

More complete example :

define $fizzbuzz #[ n -- ]#
    local @n

    @n 3 mod
    0 eq
    local @three

    @n 5 mod
    0 eq
    local @five

    "fizzbuzz" @three @five and jump :return
    pop

    "fizz" @three jump :return
    pop

    "buzz" @five jump :return
    pop

    @n

:return
    print
endef

define $count-down #[ n -- ]#
    local @n
:loop
    @n print

    @n 1 sub
    local @n

    @n 0 lst
    jump :end

    1 jump :loop
:end
endef

define $main
    17 $fizzbuzz #[ prints 17 ]#
    15 $fizzbuzz #[ prints "fizzbuzz" ]#
    9 $fizzbuzz #[ prints "fizz" ]#
    10 $fizzbuzz #[ prints "buzz" ]#

    5 $count-down
    #[
        prints 5 4 3 2 1 0
    ]#
endef

Available operations

See here