From f3b2c295808f4ff17660455c7445ec3fd8404f77 Mon Sep 17 00:00:00 2001
From: Calvin Rose <calsrose@gmail.com>
Date: Sat, 3 Feb 2018 18:12:07 -0500
Subject: [PATCH] Add pretty print to build in.

---
 src/compiler/boot.dst  | 77 +++++++++++++++++++++++-------------------
 src/compiler/compile.c | 13 +++++++
 src/core/corelib.c     |  4 +--
 3 files changed, 57 insertions(+), 37 deletions(-)

diff --git a/src/compiler/boot.dst b/src/compiler/boot.dst
index 16a61675..b4c8a0ae 100644
--- a/src/compiler/boot.dst
+++ b/src/compiler/boot.dst
@@ -77,49 +77,56 @@
      (tuple 'varset! sym (tuple '+ sym 1))
       )))
 
-(defn pp-seq [pp buf a indent start end]
- (def len (length a))
- (buffer-push-string buf start)
- (for [i 0 len]
-  (when (not= i 0) (buffer-push-string buf " "))
-  (pp buf (get a i) indent))
- (buffer-push-string buf end)
- buf)
+(def pp (do
 
-(defn push-line [buf indent]
-  (buffer-push-string buf "\n")
-  (for [i 0 indent] (buffer-push-string buf " "))
-)
+(defn pp-seq [pp seen buf a start end]
+ (if (get seen a)
+  (buffer-push-string buf "<cycle>")
+  (do
+   (put seen a true)
+   (def len (length a))
+   (buffer-push-string buf start)
+   (for [i 0 len]
+    (when (not= i 0) (buffer-push-string buf " "))
+    (pp seen buf (get a i)))
+   (buffer-push-string buf end)
+  ))
+ buf)
   
-(defn pp-dict [pp buf a indent start end]
- (var k (next a nil))
- (buffer-push-string buf start)
- (def newindent (+ 2 indent))
- (push-line buf newindent)
- (while k
-  (def v (get a k))
-  (pp buf k)
-  (buffer-push-string buf " ")
-  (pp buf v)
-  (varset! k (next a k))
-  (push-line buf (if k newindent indent))
- )
- (buffer-push-string buf end)
+(defn pp-dict [pp seen buf a start end]
+ (if (get seen a)
+  (buffer-push-string buf "<cycle>")
+  (do
+   (put seen a true)
+   (var k (next a nil))
+   (buffer-push-string buf start)
+   (while k
+    (def v (get a k))
+    (pp seen buf k)
+    (buffer-push-string buf " ")
+    (pp seen buf v)
+    (varset! k (next a k))
+    (when k (buffer-push-string buf " "))
+   )
+   (buffer-push-string buf end)
+  ))
  buf)
 
 (def _printers {
- :array  (fn [pp buf x i] (pp-seq pp buf x i "[" "]"))
- :tuple  (fn [pp buf x i] (pp-seq pp buf x i "(" ")"))
- :table  (fn [pp buf x i] (pp-dict pp buf x i "@{" "}"))
- :struct (fn [pp buf x i] (pp-dict pp buf x i "{" "}"))
+ :array  (fn [pp seen buf x] (pp-seq pp seen buf x "[" "]"))
+ :tuple  (fn [pp seen buf x] (pp-seq pp seen buf x "(" ")"))
+ :table  (fn [pp seen buf x] (pp-dict pp seen buf x "@{" "}"))
+ :struct (fn [pp seen buf x] (pp-dict pp seen buf x "{" "}"))
 })
 
-(defn _default_printer [_ buf x] (buffer-push-string buf (string x)) buf)
+(defn _default_printer [pp seen buf x] 
+ (buffer-push-string buf (string x)) 
+ buf)
 
-(defn pp1 [buf x indent]
+(defn pp1 [seen buf x]
   (def pmaybe (get _printers (type x)))
   (def p (if pmaybe pmaybe _default_printer))
-  (p pp1 buf x indent))
-
-(defn pp [x] (print (pp1 (buffer) x 0)))
+  (p pp1 seen buf x))
 
+(fn [x] (print (pp1 @{} @"" x)))
+))
diff --git a/src/compiler/compile.c b/src/compiler/compile.c
index a1c53a94..bfac314d 100644
--- a/src/compiler/compile.c
+++ b/src/compiler/compile.c
@@ -746,6 +746,15 @@ static DstSlot dstc_tablector(DstFopts opts, DstAst *ast, Dst x, DstCFunction cf
     return dstc_call(opts, ast, dstc_toslotskv(c, x), dstc_cslot(dst_wrap_cfunction(cfun)));
 }
 
+static DstSlot dstc_bufferctor(DstFopts opts, DstAst *ast, Dst x) {
+    DstCompiler *c = opts.compiler;
+    DstBuffer *b = dst_unwrap_buffer(x);
+    Dst onearg = dst_stringv(b->data, b->count);
+    return dstc_call(opts, ast,
+            dstc_toslots(c, &onearg, 1),
+            dstc_cslot(dst_wrap_cfunction(dst_core_buffer)));
+}
+
 /* Compile a symbol */
 DstSlot dstc_symbol(DstFopts opts, DstAst *ast, const uint8_t *sym) {
     if (dst_string_length(sym) && sym[0] != ':') {
@@ -846,6 +855,9 @@ recur:
         case DST_TABLE:
             ret = dstc_tablector(opts, ast, x, dst_core_table);
             break;
+        case DST_BUFFER:
+            ret = dstc_bufferctor(opts, ast, x);
+            break;
     }
     if (dstc_iserr(&opts)) {
         return dstc_cslot(dst_wrap_nil());
@@ -1009,3 +1021,4 @@ int dst_lib_compile(DstArgs args) {
     dst_env_def(env, "compile", dst_wrap_cfunction(dst_compile_cfun));
     return 0;
 }
+
diff --git a/src/core/corelib.c b/src/core/corelib.c
index 48a110bf..b0e02c23 100644
--- a/src/core/corelib.c
+++ b/src/core/corelib.c
@@ -232,12 +232,12 @@ int dst_core_next(DstArgs args) {
     if (dst_checktype(ds, DST_TABLE)) {
         DstTable *t = dst_unwrap_table(ds);
         kv = dst_checktype(args.v[1], DST_NIL)
-            ? t->data
+            ? NULL
             : dst_table_find(t, args.v[1]);
     } else if (dst_checktype(ds, DST_STRUCT)) {
         const DstKV *st = dst_unwrap_struct(ds);
         kv = dst_checktype(args.v[1], DST_NIL)
-            ? st
+            ? NULL
             : dst_struct_find(st, args.v[1]);
     } else {
         return dst_throw(args, "expected table/struct");