Hecl is a scripting language designed for mobile development that aims to be tiny, flexible, and simple; it is interpreted and dynamically typed, and can be embedded in Java applications to add scripting capabilities; the document discusses Hecl's features, syntax, embedding process, and how extensions can be created by writing Java classes that implement new commands.

8. Part II – The Language Hecl - The Mobile Scripting Language

10. Java Complement Hecl Java

11. Extending Extensions written in Java

12. Embedding Hecl Scripts

13. Code set mainform [ form label "Hello World" code { stringitem label "Hello" text "World" cmd label "Exit" code exit type exit }] setcurrent $mainform

14. Hello World

16. Words, Blocks if { > $reactor_temperature 100 } { send $warning $operators initiate_shutdown }

17. DSL's, oh my! every 1 minute run { if { updates? } { read_queue [ + $last_update 1] } }

18. proc test {name code result} { catch $code res if { eq $res $result } { ok $name } else { fail $name $res $result } }

19. test mytest1 { set foo 10 set foo [ + 10 $foo] } 20

21. Mobile Phone Code

24. Hecl Browser Dynamic updates of applications are possible!

28. public IntThing(int i) { val = i; } public IntThing(String s) { val = Integer.parseInt(s); } public static int get(Thing thing) throws HeclException { setIntFromAny(thing); IntThing getint = (IntThing)thing.val; return getint.val; }

31. The Stack proc one {} { set a 2 puts "one $a" two puts "one $a" } proc two {} { set a 4 puts "two $a" three puts "two $a" } proc three {} { set a 6 puts "three $a" } set a 1 set b 2 puts $a one puts $a 1 one 2 two 4 three 6 two 4 one 2 1

35. Embedding Hecl import org.hecl.*; ... Interp interp = new Interp(); new HeclFile().loadModule(interp); new org.hecl.fp.HeclFloat().loadModule(interp); new org.hecl.load.HeclLoad().loadModule(interp); HeclFile.sourceFile(interp, “a_hecl_file.hcl”); ... public void someEventHandler(Event ev) { Eval.eval(eventscript); }

36. Extending Hecl class IncrCmd implements Command { public void cmdCode(Interp interp, Thing[] argv) throws HeclException { int m = IntThing.get(argv[1]); int n = 1; if (argv.length > 2) { n = IntThing.get(argv[2]); } ((IntThing) argv[1].val).set(m + n); return argv[1]; } }