From 0f5312a8acd242fa01be5fdfffbf22e20e0a6920 Mon Sep 17 00:00:00 2001
From: "Michael D. Lowis" <mike@mdlowis.com>
Date: Mon, 28 Dec 2015 22:28:06 -0500
Subject: [PATCH] First attempt at generating code for if statements. horribly
 broken.

---
 source/anf.c     | 12 ++++--------
 source/codegen.c | 22 +++++++++++++++++++---
 spec/anf_spec.rb |  9 +++++++++
 3 files changed, 32 insertions(+), 11 deletions(-)

diff --git a/source/anf.c b/source/anf.c
index 2f3e8c5..3cc1f76 100644
--- a/source/anf.c
+++ b/source/anf.c
@@ -19,14 +19,10 @@ static bool isatomic(AST* tree)
 
 static bool isconst(AST* tree) {
     bool ret = isatomic(tree);
-    if (!ret) {
-        if (tree->type == AST_FNAPP) {
-            ret = isatomic(fnapp_fn(tree));
-            for (int i = 0; i < vec_size(fnapp_args(tree)); i++) {
-                ret = ret && isatomic(vec_at(fnapp_args(tree), i));
-            }
-        } else if (tree->type == AST_IF) {
-            ret = isatomic(ifexpr_cond(tree));
+    if (!ret && tree->type == AST_FNAPP) {
+        ret = isatomic(fnapp_fn(tree));
+        for (int i = 0; i < vec_size(fnapp_args(tree)); i++) {
+            ret = ret && isatomic(vec_at(fnapp_args(tree), i));
         }
     }
     return ret;
diff --git a/source/codegen.c b/source/codegen.c
index 9969850..32b6f0d 100644
--- a/source/codegen.c
+++ b/source/codegen.c
@@ -48,6 +48,16 @@ void codegen(FILE* file, AST* tree)
             break;
 
         case AST_IF:
+            fprintf(file,"    if (");
+            codegen(file, ifexpr_cond(tree));
+            fprintf(file,")\n");
+            codegen(file, ifexpr_then(tree));
+            if (ifexpr_else(tree)) {
+                fprintf(file,"\n    else\n");
+                codegen(file, ifexpr_else(tree));
+            } else {
+                fprintf(file,"    {return nil;}");
+            }
             break;
 
         case AST_FUNC:
@@ -75,12 +85,18 @@ void codegen(FILE* file, AST* tree)
             break;
 
         case AST_LET:
-            fprintf(file,"{val ");
+            fprintf(file,"    {val ");
             codegen(file, let_var(tree));
             fprintf(file," = ");
             codegen(file, let_val(tree));
-            fprintf(file,";");
-            codegen(file, let_body(tree));
+            fprintf(file,";\n");
+            if (let_body(tree)->type != AST_LET && let_body(tree)->type != AST_IF) {
+                fprintf(file,"    return ");
+                codegen(file, let_body(tree));
+                fprintf(file,";");
+            } else {
+                codegen(file, let_body(tree));
+            }
             fprintf(file,"}");
             break;
 
diff --git a/spec/anf_spec.rb b/spec/anf_spec.rb
index a22ee6d..52fce54 100644
--- a/spec/anf_spec.rb
+++ b/spec/anf_spec.rb
@@ -132,5 +132,14 @@ describe "sclpl a-normal form" do
                 "$:0"]]]
       ])
     end
+
+    it "should normalize a literal with a complex expression" do
+      expect(anf('fn() if 1 2 else 3;;')).to eq([
+        ["fn", [],
+          ["let", ["$:1", ["T_ID:bar"]],
+            ["let", ["$:0", ["T_ID:foo", "$:1"]],
+                "$:0"]]]
+      ])
+    end
   end
 end
-- 
2.52.0