Closed #67: disambiguating choice conditions

examples/labels/main.hank

@@ -7,7 +7,7 @@ B: {choice_b}
 C: {choice_c}
 * (choice_a) Choice A
 * (choice_b) Choice B
-* (choice_c) {choice_b && choice_a} Choice C
+* (choice_c) {choice_b && choice_a}? Choice C
     -> end
 - (gather) -> start
 

examples/main/extra.hank

@@ -16,7 +16,7 @@ You can include choices for the player.
     ~ flag = true;
     ~ var what_happened = "mouse";
 + Door B []opens but the room on the other side is {word}!
-* {flag} Choices can depend on logical conditions being truthy.
+* {flag}? Choices can depend on logical conditions being truthy.
     -> final_choice
 
 - -> choice_example // a hyphen gathers all choices to the same place.

examples/mindfuck/main.hank

@@ -9,8 +9,8 @@ if (start <= 2) {
     Loop #: {start}
     * A series of choices
     * In Hank script embedded in Haxe script embedded in Hank script!
-    * {start == 1} What could be more fun?
-    * {start == 2} Gosh this sucks
+    * {start == 1}? What could be more fun?
+    * {start == 2}? Gosh this sucks
     - -> sanity
     ,,,
 } else {

hank/HankBuffer.hx

@@ -321,7 +321,7 @@ class HankBuffer {
 
 	/** If the given expression comes next in the buffer, take its contents. Otherwise, return None **/
 	public function expressionIfNext(o:String, c:String):Option<String> {
-		if (cleanBuffer.startsWith(o)) {
+		if (cleanBuffer.startsWith(o) && cleanBuffer.indexOf(c) != -1) {
 			drop(o);
 			var end = cleanBuffer.indexOf(c);
 			var content = take(end);

hank/Parser.hx

@@ -13,8 +13,17 @@ import hank.HankBuffer;
 @:allow(tests.ParserTest)
 class Parser {
 	static var symbols:Array<Map<String, HankBuffer->HankBuffer.Position->ExprType>> = [
-		['INCLUDE ' => include], ['<-' => thread], ['->' => divert], ['===' => knot], ['==' => knot], ['=' => stitch], ['~' => haxeLine],
-		['```' => haxeBlock], ['-' => gather], ['*' => choice], ['+' => choice]];
+		['INCLUDE ' => include],
+		['<-' => thread],
+		['->' => divert],
+		['===' => knot],
+		['==' => knot],
+		['=' => stitch],
+		['~' => haxeLine],
+		['```' => haxeBlock],
+		['-' => gather],
+		['*' => choice],
+		['+' => choice]];
 
 	var buffers:Array<HankBuffer> = [];
 	var ast:HankAST = [];
@@ -198,7 +207,7 @@ class Parser {
 		buffer.skipWhitespace();
 		var label = buffer.expressionIfNext('(', ')');
 		buffer.skipWhitespace();
-		var condition = buffer.expressionIfNext('{', '}');
+		var condition = buffer.expressionIfNext('{', '}?');
 		buffer.skipWhitespace();
 		var output = Output.parse(buffer);
 		var divertTarget = output.takeInlineDivert();