add support for iterating over text chars

prompto · Jul 28, 2022 · 4dc802a · 4dc802a
1 parent 930b0d0
commit 4dc802a
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Showing 4 changed files with 51 additions and 3 deletions.
diff --git a/Core/src/main/java/prompto/intrinsic/PromptoString.java b/Core/src/main/java/prompto/intrinsic/PromptoString.java
@@ -1,6 +1,7 @@
 package prompto.intrinsic;
 
 import java.util.Collection;
+import java.util.Iterator;
 
 public abstract class PromptoString {
 
@@ -82,6 +83,32 @@ public static long indexOf(String s, String v, long i) {
 		int r = s.indexOf(v, (int)i -1);
 		return r + 1;
 	}
+
+	public static Iterable<Character> iterable(String s) {
+
+		return new Iterable<Character>() {
+
+			@Override
+			public Iterator<Character> iterator() {
+
+				return new Iterator<Character>() {
+
+					int i = 0;
+
+					@Override
+					public boolean hasNext() {
+						return i < s.length();
+					}
+
+					@Override
+					public Character next() {
+						return s.charAt(i++);
+					}
+
+				};
+			}
+		};
+	}
 
 
 

diff --git a/Core/src/main/java/prompto/statement/ForEachStatement.java b/Core/src/main/java/prompto/statement/ForEachStatement.java
@@ -21,6 +21,7 @@
 import prompto.error.PromptoError;
 import prompto.expression.IExpression;
 import prompto.grammar.Identifier;
+import prompto.intrinsic.PromptoString;
 import prompto.parser.ICodeSection;
 import prompto.parser.ISection;
 import prompto.runtime.BreakResult;
@@ -341,9 +342,13 @@ private ResultInfo compileWithoutIndex(Context context, MethodInfo method, Flags
 	}
 
 	private StackLocal compileIterator(Context context, MethodInfo method, Flags flags) {
-		source.compile(context, method, flags);
-		InterfaceConstant m = new InterfaceConstant(Iterable.class, "iterator", Iterator.class);
-		method.addInstruction(Opcode.INVOKEINTERFACE, m);
+		ResultInfo info = source.compile(context, method, flags);
+		if(info.getType() == String.class) {
+			MethodConstant mc = new MethodConstant(PromptoString.class, "iterable", String.class, Iterable.class);
+			method.addInstruction(Opcode.INVOKESTATIC, mc);
+		}
+		InterfaceConstant ic = new InterfaceConstant(Iterable.class, "iterator", Iterator.class);
+		method.addInstruction(Opcode.INVOKEINTERFACE, ic);
 		String iterName = method.nextTransientName("iter");
 		StackLocal iterLocal = method.registerLocal(iterName, VerifierType.ITEM_Object, new ClassConstant(Iterator.class));
 		method.addInstruction(Opcode.ASTORE, new ByteOperand((byte)iterLocal.getIndex()), new ClassConstant(Iterator.class));

diff --git a/Core/src/main/java/prompto/type/TextType.java b/Core/src/main/java/prompto/type/TextType.java
@@ -130,6 +130,12 @@ public IType checkSlice(Context context) {
 		return this;
 	}
 
+	@Override
+	public IType checkIterator(Context context) {
+		return CharacterType.instance();
+	}
+
+
 	@Override
 	public Set<IMethodDeclaration> getMemberMethods(Context context, Identifier id) throws PromptoError {
 		switch(id.toString()) {

diff --git a/Core/src/main/resources/prompto/intrinsic/Utils.js b/Core/src/main/resources/prompto/intrinsic/Utils.js
@@ -208,6 +208,16 @@ String.prototype.equals = function(value) {
     // use == because === fails in Nashorn
 	return this == value;
 };
+
+String.prototype.iterator = function() {
+	var s = this;
+	return {
+		idx: 0,
+		hasNext: function() { return this.idx < s.length; },
+		next: function() { return s[this.idx++]; }
+	};
+};
+
 var intrinsic = {};
 
 if(typeof(window)==="object" && window.document) {