# Difference between revisions of "Plankalkül"

(Test) |
|||

Line 10: | Line 10: | ||

|} | |} | ||

− | |||

=== 2D syntax 'sidebar' === | === 2D syntax 'sidebar' === |

## Revision as of 14:49, 24 November 2006

## 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 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?