# Difference between revisions of "Plankalkül"

## Project Plankalkül

### Spec

#### Variables

 V parameters (r/o) Z temporaries (r/w) R results (w/o)

#### 2D syntax 'sidebar'

In the 2D notation there is a vertical column on the right where the value of elements in that row is indicated:

``` |Main Line
V|Variable Number
K|Component Number
S|Comment Line
```

So, as an example:

``` |Z  ^ Z
V|4    2
K|2.3
S|0    0
```

(from page 8 in the Zuse PDF). This is (probably) equivalent to:

```Z4[2.3] ^ Z2
```

in the linear notation.

#### Primitives

The only primitive type is boolean (or a bit). They are denoted by S0.

#### Arrays

Arrays can be made up of any other data type. For example:

```8 X S0
```

is an array of 8 bits whereas:

```n X 4 X S0
```

is an array of n arrays of bits each with length 4.

Arrays can be subscripted:

``` |V
V|0
K|1
```

means the 1st component of V0 (linear syntax is V0[1]).

#### Records

Page 2 of Bauer alludes to 'records' of the form (A2, A3). We need more info here.

### Questions

• Are S (and maybe A) variables or types or constants or what? We know S0 is the boolean bit, S1 is an array of boolean bits and apparently S2 is a constant of some type.
• What is the difference between S and A?
• How is a function declared? The Bauer PDF gives this syntax:
```P17 |R(V) => (R, R)
V|  0      0  1
S|  α      α  0
```

but.. how is this function called?, how do you actually define stuff to occur in the function, is the 'FIN' end symbol used?

### Implementation

Is the 2d syntax representable in ascii in some obvious way? What are the advantages of the 2d syntax?