From 9674d95e559c281559cff625698edb5edef4edfd Mon Sep 17 00:00:00 2001
From: glathoud <glat@glat.info>
Date: Wed, 8 Aug 2018 19:35:51 +0200
Subject: [PATCH] #12 self-inlining (of appfun externals)

---
 test.js     | 29 +++++++++++++++++++++++++++++
 transfun.js |  5 +++++
 2 files changed, 34 insertions(+)

diff --git a/test.js b/test.js
index 8df9fad..d0d0620 100644
--- a/test.js
+++ b/test.js
@@ -593,7 +593,36 @@ var global, exports;
         ,   obtained = quite_protracted_and_synthetic_example_3( 7, 8 )
         ;
         expected === obtained  ||  null.bug;
+
+        // Inlining of generated appfun when used as external
+        // functions, see:
+        // https://github.com/glathoud/transfun/issues/12
+
+        var get_mean = tfun.redinit( '0', '+' ).next( '/n' )
+        ,  get_stddev = tfun
+            .decl( 'mean_value', get_mean )
+            .map( 'v-mean_value' )
+            .map( 'v*v' )
+            .sum()
+            .next( 'Math.sqrt(current/(n-1))' )  // unbiased std dev estimation
+        
+        // compute both mean and stddev at once
+        , get_mean_stddev = get_stddev
+            .next( '{stddev:current, mean:mean_value}')
+        ;
+
+        var arr = [ 0.1, 0.2, 0.345, 0.456, 0.42342, 0.12 ]
+        ,   arr_mean = arr.reduce( function ( a, b ) { return a+b; }, 0 ) / arr.length
+        ,   arr_std  = Math.sqrt( arr.reduce( function ( a, b ) { return a+(b-arr_mean)*(b-arr_mean); }, 0 ) / (arr.length - 1) )
+
+        ,   o = get_mean_stddev( arr )
+        ;
+        1e-10 > Math.abs( o.mean   - arr_mean )  ||  null.bug;
+        1e-10 > Math.abs( o.stddev - arr_std )  ||  null.bug;
         
+        !/extern/.test( get_mean_stddev.getBodyCode() )  ||  null.bug;
+        // xxx !/\bvar\b/.test( get_mean_stddev.getBodyCode() )  ||  null.bug;
+
         // 
         
         console.timeEnd( 'transfun:test' );
diff --git a/transfun.js b/transfun.js
index 5f6000e..33b5378 100644
--- a/transfun.js
+++ b/transfun.js
@@ -906,6 +906,11 @@ var global, exports; // NPM support [github#1]
                     appfun.getNExternal = appfun_getNExternal;
 		    
 		    cached_appfun = chainspec.appfun = mix_published_tfun_methods_into_appfun( chainspec, appfun );
+
+                    // API for inlining when appfun are used as externals
+                    // https://github.com/glathoud/transfun/issues/12
+                    appfun[ _TF_GET_BODYCODE ]    = appfun_getBodyCode;
+                    appfun[ _TF_GET_ARGNAME_ARR ] = function () { return code_par_arr.slice( extern_arr.length ); };
                 }
                 return cached_appfun;