From 7d1a49c18ed17ddfc0bdbdfba5e6e7c99912cab9 Mon Sep 17 00:00:00 2001
From: Nat Quayle Nelson <natquaylenelson@gmail.com>
Date: Mon, 18 Oct 2021 13:09:05 -0400
Subject: [PATCH] AsyncEmbeddedScript

---
 src/kiss/AsyncEmbeddedScript.hx | 160 ++++++++++++++++++++++++++++++++
 1 file changed, 160 insertions(+)
 create mode 100644 src/kiss/AsyncEmbeddedScript.hx

diff --git a/src/kiss/AsyncEmbeddedScript.hx b/src/kiss/AsyncEmbeddedScript.hx
new file mode 100644
index 0000000..04fa40e
--- /dev/null
+++ b/src/kiss/AsyncEmbeddedScript.hx
@@ -0,0 +1,160 @@
+package kiss;
+
+#if macro
+import haxe.macro.Expr;
+import haxe.macro.Context;
+import haxe.macro.PositionTools;
+import sys.io.File;
+import haxe.io.Path;
+#end
+import kiss.Kiss;
+import kiss.cloner.Cloner;
+
+
+typedef Continuation = () -> Void;
+typedef AsyncCommand = (AsyncEmbeddedScript, Continuation) -> Void;
+
+/**
+    Utility class for making statically typed, debuggable, ASYNC-BASED embedded Kiss-based DSLs.
+    Examples are in the hollywoo project.
+**/
+class AsyncEmbeddedScript {
+    private var instructions:Array<AsyncCommand> = null;
+    private var breakPoints:Map<Int, () -> Bool> = [];
+    private var onBreak:AsyncCommand = null;
+
+    public function setBreakHandler(handler:AsyncCommand) {
+        onBreak = handler;
+    }
+
+    public function addBreakPoint(instruction:Int, ?condition:() -> Bool) {
+        if (condition == null) {
+            condition = () -> true;
+        }
+        breakPoints[instruction] = condition;
+    }
+
+    public function removeBreakPoint(instruction:Int) {
+        breakPoints.remove(instruction);
+    }
+
+    public function new() {}
+
+    #if macro
+    public static function build(dslFile:String, scriptFile:String):Array<Field> {
+        var k = Kiss.defaultKissState();
+
+        var classPath = Context.getPosInfos(Context.currentPos()).file;
+        var loadingDirectory = Path.directory(classPath);
+        var classFields = Context.getBuildFields();
+
+        var commandList:Array<Expr> = [];
+
+        // This brings in the DSL's functions and global variables.
+        // As a side-effect, it also fills the KissState with the macros and reader macros that make the DSL syntax
+        classFields = classFields.concat(Kiss.build(dslFile, k));
+        scriptFile = Path.join([loadingDirectory, scriptFile]);
+
+        Reader.readAndProcess(Stream.fromFile(scriptFile), k, (nextExp) -> {
+            var expr = Kiss.readerExpToHaxeExpr(nextExp, k);
+
+            if (expr != null) {
+                commandList.push(macro function(self, cc) {
+                    $expr;
+                });
+            }
+
+            // This return is essential for type unification of concat() and push() above... ugh.
+            return;
+        });
+
+        classFields.push({
+            pos: PositionTools.make({
+                min: 0,
+                max: File.getContent(scriptFile).length,
+                file: scriptFile
+            }),
+            name: "resetInstructions",
+            access: [APrivate],
+            kind: FFun({
+                ret: null,
+                args: [],
+                expr: macro this.instructions = [$a{commandList}]
+            })
+        });
+
+        classFields.push({
+            pos: PositionTools.make({
+                min: 0,
+                max: File.getContent(scriptFile).length,
+                file: scriptFile
+            }),
+            name: "instructionCount",
+            access: [APublic],
+            kind: FFun({
+                ret: null,
+                args: [],
+                expr: macro {
+                    if (instructions == null)
+                        resetInstructions();
+                    return instructions.length;
+                }
+            })
+        });
+
+        classFields.push({
+            pos: PositionTools.make({
+                min: 0,
+                max: File.getContent(scriptFile).length,
+                file: scriptFile
+            }),
+            name: "runInstruction",
+            access: [APublic],
+            kind: FFun({
+                ret: null,
+                args: [
+                    {name: "instructionPointer"},
+                    {
+                        name: "withBreakPoints",
+                        value: macro true
+                    }
+                ],
+                expr: macro {
+                    if (instructions == null)
+                        resetInstructions();
+                    if (withBreakPoints && breakPoints.exists(instructionPointer) && breakPoints[instructionPointer]()) {
+                        if (onBreak != null) {
+                            onBreak(this, () -> runInstruction(instructionPointer, false));
+                        }
+                    }
+                    var continuation = if (instructionPointer < instructions.length - 1) {
+                        () -> runInstruction(instructionPointer + 1);
+                    } else {
+                        () -> {};
+                    }
+                    instructions[instructionPointer](this, continuation);
+                }
+            })
+        });
+
+        classFields.push({
+            pos: PositionTools.make({
+                min: 0,
+                max: File.getContent(scriptFile).length,
+                file: scriptFile
+            }),
+            name: "run",
+            access: [APublic],
+            kind: FFun({
+                ret: null,
+                args: [],
+                expr: macro {
+                    runInstruction(0);
+                }
+            })
+        });
+
+       return classFields;
+    }
+    #end
+}