Liz's L-Program Compiler

// 0. primitive instructions only

// 1. anything following the comment token "//" up to a

//    newline are ignored.

// 2. by default, a computation that takes more than 500_000

//    "procedures", it will be halted.

// 3. the implicit exit label "E1" exists; thus to exit

//    prematurely, "GOTO E1".

// 4. input your initial snapshot in the "variables" map

//    on the Program in the compiled JS output

// 5. for a more detailed view on the grammar, it's at

//    /godel/grammar.peg

​

// THIS PROGRAM COMPUTES X1 + X2

​

// Y <- X1

[ A1 ] IF X1 != 0 GOTO A2

       GOTO B1

[ A2 ] X1 <- X1 - 1

       Y <- Y + 1

       GOTO A1

​

// Z1 <- X2

[ B1 ] IF X2 != 0 GOTO B2

       GOTO C1

[ B2 ] X2 <- X2 - 1

       Z1 <- Z1 + 1

       GOTO B1

​

// Y <- Y + Z1

[ C1 ] IF Z1 != 0 GOTO C2

       GOTO E1

[ C2 ] Z1 <- Z1 - 1

       Y <- Y + 1

       GOTO C1

​