SSREPL

SSREPL(Simple String-Rewriting Esoteric Programming Language) is an esolang by User:ChuckEsoteric08.

Specification

Initial value Data String is taken from user input. Line numbers are 1-indexed. There is only one instruction:

x=y!z

If there is x in Data String replace it with y, else goto line z.

Computational class

SSREPL is Turing complete, which is proven by this Cyclic Tag interpreter:

^@=@!6
@#=@!4
*=*!19
$=$^!19
*=*!1
^;=;^!11
@0=@!9
*=*!1
@1=@!19
*=*!1
^1=1^!15
@1=@1!1
#=1#!19
*=*!1
^0=0^!19
@1=@1!1
#=0#!19
*=*!1
@=@!19

Initial Data String should look like this: $^Program@Data#.