Changes between Version 3 and Version 4 of HllInteroperability

Timestamp:

06/26/09 19:00:44 (13 years ago)

Author:

tene

Comment:

Add a usage example

HllInteroperability

@@ -1 +1 @@
 = General Issues =
 * Until case mangling issues in Parrot are fixed, you must use an all-lowercase HLL name (someone plz add TT#)
+* Due to current bugs in Parrot, the 'load_language' opcode *must* be called from the 'parrot' HLL
 = Library Loading =
 To provide other languages access to libraries written in your language, you must add a 'load_library' method to your compiler object.  This method must accept one positional parameter, a list (or ::-delimited string?) representing the name of the library to load, and an arbitrary quantity of other named parameters (:named :slurpy), which it is (currently) free to ignore.  This method should return a hash containing the following attributes:
@@ -19 +20 @@
 
 For existing implementations of this, look at runtime/parrot/languages/parrot/parrot.pir in the Parrot repository and perl6.pir in the rakudo repository.
+
+An example implementation of a 'foreign_load' function:
+{{{
+.sub 'foreign_load'
+    .param string lang
+    .param string module
+    .local pmc compiler, name, library, imports, callerns, foreignlibns
+    $P0 = getinterp
+    callerns = $P0['namespace';1]
+    'load-language'(lang)
+    compiler = compreg lang
+    name = split '::', module
+    library = compiler.'load_library'(name)
+    imports = library['symbols']
+    imports = imports['DEFAULT']
+    .local pmc iter, item
+    iter = new 'Iterator', imports
+  import_loop:
+    unless iter goto import_loop_end
+    $S0 = shift iter
+    $P0 = imports[$S0]
+    callerns[$S0] = $P0
+    goto import_loop
+  import_loop_end:
+    foreignlibns = library['namespace']
+    if null foreignlibns goto no_foreign_ns
+    $S0 = pop name
+    set_hll_global name, $S0, foreignlibns
+  no_foreign_ns:
+    .return (library)
+.end
+}}}