String interpolation (included): Difference between revisions

Algol 68 allows a string to be used as a file, the following (based on the above) uses this to construct the string which can then be further processed. In this sample, variable strings and formats are used though in general it would be hard to construct the extraf format at run-time as Algol 68 has no facilities to construct formats on the fly.

<syntaxhighlight lang="algol68">

BEGIN

FILE str file;

STRING mhl;

associate( str file, mhl );

STRING extra := "little";

TO 2 DO

putf( str file, ( $"Mary had a "g" lamb."$, extra ) );

print( ( "1 result is: {{", mhl, "}}", newline ) );

mhl := "";

"supposedlly-" +=: extra

OD;

FORMAT extraf := $"little"$;

TO 2 DO

putf( str file, ( $"Mary had a "f(extraf)" lamb."$ ) );

print( ( "2 result is: {{", mhl, "}}", newline ) );

mhl := "";

extraf := $"medium-sized"$

OD

END

</syntaxhighlight>

{{out}}

<pre>

1 result is: {{Mary had a little lamb.}}

1 result is: {{Mary had a supposedlly-little lamb.}}

2 result is: {{Mary had a little lamb.}}

2 result is: {{Mary had a medium-sized lamb.}}

</pre>