From 3afad56f71d58f75f3ff47379483090c00c33622 Mon Sep 17 00:00:00 2001
From: Nat Quayle Nelson <natquaylenelson@gmail.com>
Date: Wed, 9 Dec 2020 21:46:07 -0700
Subject: [PATCH] Refactor reader macros in AOC Day 8 pt 1

---
 kiss/src/kiss/Helpers.hx                   | 12 ++++++--
 kiss/src/kiss/Reader.hx                    |  8 +++--
 kiss/src/kiss/Stream.hx                    |  2 +-
 projects/aoc/src/year2020/BootCodeDSL.kiss | 34 +++++-----------------
 4 files changed, 25 insertions(+), 31 deletions(-)

diff --git a/kiss/src/kiss/Helpers.hx b/kiss/src/kiss/Helpers.hx
index f5fd1350..0be308d5 100644
--- a/kiss/src/kiss/Helpers.hx
+++ b/kiss/src/kiss/Helpers.hx
@@ -197,6 +197,7 @@ class Helpers {
         interp.variables.set("read", Reader.assertRead.bind(_, k.readTable));
         interp.variables.set("readExpArray", Reader.readExpArray.bind(_, _, k.readTable));
         interp.variables.set("ReaderExp", ReaderExpDef);
+        interp.variables.set("nextToken", Reader.nextToken.bind(_, "a token"));
         interp.variables.set("kiss", {
             Reader: {
                 ReaderExpDef: ReaderExpDef
@@ -247,8 +248,15 @@ class Helpers {
                 FieldExp(field, evalUnquotes(innerExp, k, args));
             case KeyValueExp(keyExp, valueExp):
                 KeyValueExp(evalUnquotes(keyExp, k, args), evalUnquotes(valueExp, k, args));
-            case Unquote(exp):
-                runAtCompileTime(exp, k, args).def;
+            case Unquote(innerExp):
+                var unquoteValue:Dynamic = runAtCompileTime(innerExp, k, args);
+                if (unquoteValue == null) {
+                    throw CompileError.fromExp(innerExp, "unquote evaluated to null");
+                } else if (Std.isOfType(unquoteValue, ReaderExpDef)) {
+                    unquoteValue;
+                } else {
+                    unquoteValue.def;
+                };
             default:
                 throw CompileError.fromExp(exp, 'unquote evaluation not implemented');
         };
diff --git a/kiss/src/kiss/Reader.hx b/kiss/src/kiss/Reader.hx
index 124b78b2..45616fdd 100644
--- a/kiss/src/kiss/Reader.hx
+++ b/kiss/src/kiss/Reader.hx
@@ -93,8 +93,12 @@ class Reader {
 
     public static final terminators = [")", "]", "/*", "\n", " "];
 
-    static function nextToken(stream:Stream, expect:String) {
-        return stream.expect(expect, () -> stream.takeUntilOneOf(terminators));
+    public static function nextToken(stream:Stream, expect:String) {
+        var tok = stream.expect(expect, () -> stream.takeUntilOneOf(terminators));
+        if (tok.length == 0) {
+            throw 'Expected token $expect at ${stream.position()}';
+        }
+        return tok;
     }
 
     public static function assertRead(stream:Stream, readTable:Map<String, ReadFunction>):ReaderExp {
diff --git a/kiss/src/kiss/Stream.hx b/kiss/src/kiss/Stream.hx
index 4531d99f..7fc3175c 100644
--- a/kiss/src/kiss/Stream.hx
+++ b/kiss/src/kiss/Stream.hx
@@ -158,7 +158,7 @@ class Stream {
         switch (f()) {
             case Some(s):
                 return s;
-            case None:
+            default:
                 throw 'Expected $whatToExpect at $position';
         }
     }
diff --git a/projects/aoc/src/year2020/BootCodeDSL.kiss b/projects/aoc/src/year2020/BootCodeDSL.kiss
index f2efb688..efa0e5d5 100644
--- a/projects/aoc/src/year2020/BootCodeDSL.kiss
+++ b/projects/aoc/src/year2020/BootCodeDSL.kiss
@@ -1,28 +1,10 @@
 (load "BootCodeCommon.kiss")
 
-(defreadermacro "" [stream] #| ReaderExp.CallExp(
-        {
-            pos: {file: "bleh", line: 1, column: 1, absoluteChar: 1},
-            def: ReaderExp.Symbol(stream.expect("an instruction", function () { stream.takeUntilAndDrop(" "); }))
-        },
-        [
-            {
-                pos: {file: "fefea", line: 1, column: 1, absoluteChar: 1},
-                def: ReaderExp.CallExp(
-                    {
-                        pos: {file: "treh", line: 1, column: 1, absoluteChar: 1},
-                        def: ReaderExp.Symbol(stream.expect("+/-", function () { stream.takeChars(1); }))
-                    },
-                    [
-                        {
-                            pos: {file: "smeeh", line: 1, column: 1, absoluteChar: 1},
-                            def: ReaderExp.Symbol("0")
-                        },
-                        {
-                            pos: {file: "greeeh", line: 1, column: 1, absoluteChar: 1},
-                            def: ReaderExp.Symbol(stream.expect("an argument", function () { stream.takeUntilAndDrop("\n"); }))
-                        }
-                    ])
-            }
-        ])
-    |#)
\ No newline at end of file
+(defreadermacro "" [stream]
+    `(,(ReaderExp.Symbol 
+            (begin (stream.dropWhitespace) (nextToken stream)))
+        (,(ReaderExp.Symbol 
+            (begin (stream.dropWhitespace) (stream.expect "+/-" (lambda [] (stream.takeChars 1)))))
+                0
+                ,(ReaderExp.Symbol
+                     (nextToken stream)))))
\ No newline at end of file