Triskaidekalogophilia

Triskaidekalogophilia is an esolang with only 9 commands that only allow string manipulation. The commands can add, delete or change characters within a string. The name derives from the words describing the love of the number 13 and the love of words.

Syntax

<Variable

Prints the value stored in Variable.

>Variable;Prompt

Saves a user-inputted string in Variable with the prompt coming from the variable Prompt.

^Variable;Index

Increases the ASCII value of the character at Index in Variable by 1. 127 becomes 0.

*Variable

Removes the last character in Variable.

+Variable

Adds a character with an ASCII value of 0 to the end of Variable.

?Variable;Index;Result

Places the character in Variable at Index in Result.

=Variable1;Variable2

Executes the next command if the two variables are equal. If not, that line is skipped.

@LineNumber

Goes to the specified line.

#

Returns to the line after the last @ command. If there has already been a # command or no @ command the program returns to the beginning.

All numbers must be given in base-13 0-C, the case is irrelevant.

Examples

Cat program

+nil
*nil
>line;nil
<line
#

Interpreter

This is the code for the interpreter written in Python 3.3:

 import time
 Commands = {}
 Variables = {}
 
 def INPUT(String):
     String = String.split(';',1)
     if String[1] in Variables:
         Variables[String[0]] = input(Variables[String[1]])
 
 def PRINT(String):
     if String in Variables:
         print(Variables[String])
 
 def SHIFT(String):
     String = String.split(';',1)
     if String[0] in Variables:
         try:
             if not String[1] in Variables:
                 Index = 0
             else:
                 Index = int(Variables[String[1]],13)
             Variables[String[0]] = list(Variables[String[0]])
             Value = ord(Variables[String[0]][Index])
             Value = (Value+1)%128
             Variables[String[0]][Index] = chr(Value)
             Variables[String[0]] = ''.join(Variables[String[0]])
         except ValueError:
             pass
 
 def DELCHAR(String):
     if not String in Variables:
         Variables[String] = ''
     Variables[String] = Variables[String][:-1]
 
 def ADDCHAR(String):
     if not String in Variables:
         Variables[String] = ''
     Variables[String] = list(Variables[String])
     Variables[String].append(chr(0))
     Variables[String] = ''.join(Variables[String])
 
 def GETCHAR(String):
     String = String.split(';',2)
     if String[0] in Variables and String[1] in Variables:
         try:
             Index = int(Variables[String[1]],13)
             Variables[String[2]] = Variables[String[0]][Index]
         except ValueError:
             pass
 
 def EQUAL(String):
     global LineNumber
     String = String.split(';',1)
     if String[0] in Variables and String[1] in Variables:
         if Variables[String[0]] != Variables[String[1]]:
             LineNumber += 1
 
 def GOTO(String):
     global LineNumber
     global LastJump
     LastJump = LineNumber
     LineNumber = int(Variables[String],13)
 
 def RETURN(String):
     global LineNumber
     global LastJump
     LineNumber = LastJump
     LastJump = 0
 
 Commands[">"] = INPUT
 Commands["<"] = PRINT
 Commands["^"] = SHIFT
 Commands["*"] = DELCHAR
 Commands["+"] = ADDCHAR
 Commands["?"] = GETCHAR
 Commands["="] = EQUAL
 Commands["@"] = GOTO
 Commands["#"] = RETURN
 
 File = [Foo.replace('\n','') for Foo in open(input("File: ")).readlines()]
 global LineNumber
 global LastJump
 LineNumber = 0
 LastJump = 0
 while LineNumber < len(File):
     Line = File[LineNumber]
     for Command in Commands:
         if Command == Line[0]:
             Function = Commands[Command]
             break
         else:
             Function = 'Comment'
     if Function != 'Comment':
         Function(Line[1:])
     LineNumber += 1
 
 print('\n=== END ===')
 time.sleep(5)