# Plankalkül

## Spec

### Variables

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

Math test: $\begin{bmatrix}  0 & \cdots & 0 \\ \vdots & \ddots & \vdots \\ 0 & \cdots & 0  \end{bmatrix}$

### 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 n-length array with each element being a 4-length array of bits.

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?