Widening ¶

Meaning ¶

Widening is one of the six coercions. It is allowed in strong syntactic positions. This coercion transforms:

• Integers to real numbers of the same longsety.
• Real numbers to complex numbers of the same longsety.
• A bits value to an unpacked row of booleans.
• A bytes value to an unpacked row of characters.

Some implementations (like Algol 68 Genie) extend the meaning of widening by allowing transformations from, say, int to long int or from long real to long long real, but this is not allowed in the strict language, which requires using the leng and shorten operators instead.

Syntax ¶

Simplified [RR 6.5.1.a:d]:

a) widened to SIZETY real FORM:
     MEEK SIZETY integral FORM.
b) widened to structured with SIZETY real field re
                              SIZETY real field im mode FORM:
     MEEK SIZETY real FORM;
     widened to SIZETY real FORM.
c) widened to row of boolean FORM:
     MEEK BITS FORM.
d) widened to row of character FORM:
     MEEK BYTES FORM.

See Also ¶

• Coercion
• [RR 6.5]