Function definition: Difference between revisions

=={{header|Amazing Hopper}}==

Hopper has no functions, but they can be declared with macros, which are resolved at compile time. Access to the working stack is global, but "local" variables can be declared in program segments written after the ".locals" clause. Let's look at some examples of declaring "functions".

<syntaxhighlight lang="c">

/* this need data into stack */

#context Multiplication

mul

Return \\

#synon Multiplication *getproduct

#context-free anothermul

/* #defn Args(*) #GENCODE $$$*$$$ #REVLIST=0,mov(#REVLIST);#ENDGEN, */

Args 'a,b'

Return ( #(a*b) )\\

#synon anothermul *getanotherproduct

#include <jambo.h>

#prototype _multiply(_X_,_Y_)

#synon __multiply Multiply

Main

/* "prototipos" of functions and procedures.

Solves internaly */

Printnl ( Multiply ( 10, 4 ) )

Printnl ( __multiply ( 10, 4 ) )

/* definición alternativa 1 */

Printnl ( Set' 10,4 ', Gosub ' Multiply2 ')

/* aseembler Hopper 1 */

{10,4} jsub( Multiply3 ), {"\n"} print

/* assembler Hopper 2 */

{10,4} jsub( Multiply4 ), {"\n"} print

/* context */

Set '10,4', now get product, and print with newline

/* context-free */

Set '10,4', and get another product; then print with newline

End

.locals /* Subrutines */

_multiply(a,b)

Return ( Mul(a,b) )

/* Define is macro. Others macros: Function, Procedure:

#defn Define(_F_,*) _F_:,#GENCODE $$$*$$$ #REVLIST=0;mov(#REVLIST);#ENDGEN;

#defn Function(_F_,*) _F_:,#GENCODE $$$*$$$ #REVLIST=0;mov(#REVLIST);#ENDGEN;

#defn Procedure(_F_,*) _F_:,#GENCODE $$$*$$$ #REVLIST=0;mov(#REVLIST);#ENDGEN;

*/

Define 'Multiply2, a,b'

Return ( Mul(a,b) )

Multiply3:

b=0, mov(b), a=0, mov(a)

{a,b}mul /* result into stack */

Return

Multiply4:

mul /* get values from stack,

and put result into stack */

back /* Return */

</syntaxhighlight>

{{out}}

<pre>

40.000000

40.000000

40.000000

40.000000

40.000000

40.000000

40.000000

</pre>