reada

Purpose

Parse SETL values from a file.

 reada(file, var1, var2 ... )

Read a string representation of o SETL value from a file (as written to the file by printa.)

In CIMS SETL and SETL-S, file must be the filename of a previously-opened file.

In SETL2, file must be a handle to a previously-opened file.

In GNU SETL, file may be a file descriptor or filename. If a filename is given which is not already open, it is automatically opened for input.

Any leading spaces in the input are skipped, and parsing always starts from the beginning of a line.

If the end of the stream is reached part-way through the argument list, trailing variables are assigned om.

Comma separation is optional in the representation of tuples and sets.

If data.txt has the following contents:

4
p 'q r' s t
w [x y] z

then after

open("data.txt", "TEXT-IN");
reada("data.txt", a, b);
reada("data.txt", c, d);
reada("data.txt", e, f);
reada("data.txt", g, h);

The variables a..h will be assigned as follows:

a => 4
b => 'p'
c => 'q r'
d => 's'
e => 'w'
f => ['x', 'y']
g => 'z'
h => om

Note that 't' is skipped because the third call to read advances to the next line before reading into e.