[c] Refactor string.Substring.

6 files changed, 154 insertions, 118 deletions

diff --git a/GenC.fu b/GenC.fu
index 5753c7c..13a6f03 100644
--- a/GenC.fu
+++ b/GenC.fu
@@ -118,15 +118,15 @@ public class GenC : GenCCpp
 			WriteTemporaryOrExpr(expr, FuPriority.Argument);
 	}
 
-	void WriteStringPtrAdd!(FuExpr? obj, bool utf8GetString, List<FuExpr#> args, bool cast)
+	void WriteStringPtrAdd!(FuCallExpr call, bool cast)
 	{
-		if (utf8GetString) {
+		if (IsUTF8GetString(call)) {
 			if (cast)
 				Write("(const char *) ");
-			WriteArrayPtrAdd(args[0], args[1]);
+			WriteArrayPtrAdd(call.Arguments[0], call.Arguments[1]);
 		}
 		else
-			WriteArrayPtrAdd(obj, args[0]);
+			WriteArrayPtrAdd(call.Method.Left, call.Arguments[0]);
 	}
 
 	static bool IsDictionaryClassStgIndexing(FuExpr expr)
@@ -184,7 +184,7 @@ public class GenC : GenCCpp
 		if (call != null) {
 			GetStringSubstringLength(call).Accept(this, FuPriority.Argument);
 			Write(", ");
-			WriteStringPtrAdd(call.Method.Left, IsUTF8GetString(call), call.Arguments, true);
+			WriteStringPtrAdd(call, true);
 		}
 		else if (expr.Type is FuClassType klass && klass.Class.Id != FuId.StringClass) {
 			// TODO: abstract, virtual, override
@@ -781,17 +781,7 @@ public class GenC : GenCCpp
 
 	void WriteStringStorageValue!(FuExpr expr)
 	{
-		FuCallExpr? call = IsStringSubstring(expr);
-		if (call != null) {
-			Include("string.h");
-			this.StringSubstring = true;
-			Write("FuString_Substring(");
-			WriteStringPtrAdd(call.Method.Left, IsUTF8GetString(call), call.Arguments, true);
-			Write(", ");
-			GetStringSubstringLength(call).Accept(this, FuPriority.Argument);
-			WriteChar(')');
-		}
-		else if (expr.IsNewString(false))
+		if (expr.IsNewString(false))
 			expr.Accept(this, FuPriority.Argument);
 		else {
 			Include("string.h");
@@ -1578,7 +1568,7 @@ public class GenC : GenCCpp
 			WriteChar('(');
 		Include("string.h");
 		Write("memcmp(");
-		WriteStringPtrAdd(call.Method.Left, IsUTF8GetString(call), call.Arguments, false);
+		WriteStringPtrAdd(call, false);
 		Write(", ");
 		VisitLiteralString(literal);
 		Write(", ");
@@ -1929,17 +1919,14 @@ public class GenC : GenCCpp
 		WriteChar(')');
 	}
 
-	protected void WriteStringSubstring!(FuExpr obj, List<FuExpr#> args, FuPriority parent)
+	protected void WriteStringSubstringStart!(FuExpr obj, List<FuExpr#> args, FuPriority parent)
 	{
-		if (args.Count == 1) {
-			if (parent > FuPriority.Add)
-				WriteChar('(');
-			WriteAdd(obj, args[0]);
-			if (parent > FuPriority.Add)
-				WriteChar(')');
-		}
-		else
-			NotSupported(obj, "Substring");
+		assert args.Count == 1;
+		if (parent > FuPriority.Add)
+			WriteChar('(');
+		WriteAdd(obj, args[0]);
+		if (parent > FuPriority.Add)
+			WriteChar(')');
 	}
 
 	void StartArrayContains!(FuExpr obj)
@@ -2061,7 +2048,17 @@ public class GenC : GenCCpp
 				WriteChar(')');
 			break;
 		case FuId.StringSubstring:
-			WriteStringSubstring(obj, args, parent);
+			if (args.Count == 1)
+				WriteStringSubstringStart(obj, args, parent);
+			else {
+				Include("string.h");
+				this.StringSubstring = true;
+				Write("FuString_Substring(");
+				WriteArrayPtrAdd(obj, args[0]);
+				Write(", ");
+				args[1].Accept(this, FuPriority.Argument);
+				WriteChar(')');
+			}
 			break;
 		case FuId.StringToLower:
 			WriteGlib("g_utf8_strdown(");
@@ -2357,6 +2354,15 @@ public class GenC : GenCCpp
 			args[0].Accept(this, FuPriority.Argument); // FIXME: side effect
 			Write("))");
 			break;
+		case FuId.UTF8GetString:
+			Include("string.h");
+			this.StringSubstring = true;
+			Write("FuString_Substring((const char *) ");
+			WriteArrayPtrAdd(args[0], args[1]);
+			Write(", ");
+			args[2].Accept(this, FuPriority.Argument);
+			WriteChar(')');
+			break;
 		case FuId.EnvironmentGetEnvironmentVariable:
 			WriteCall("getenv", args[0]);
 			break;
diff --git a/GenCl.fu b/GenCl.fu
index 123905a..02f2bac 100644
--- a/GenCl.fu
+++ b/GenCl.fu
@@ -199,7 +199,10 @@ public class GenCl : GenC
 			}
 			break;
 		case FuId.StringSubstring:
-			WriteStringSubstring(obj, args, parent);
+			if (args.Count == 1)
+				WriteStringSubstringStart(obj, args, parent);
+			else
+				NotSupported(obj, "Substring");
 			break;
 		case FuId.ArrayCopyTo:
 			Write("for (size_t _i = 0; _i < ");
diff --git a/libfut.cpp b/libfut.cpp
index ab92efe..0e9e81e 100644
--- a/libfut.cpp
+++ b/libfut.cpp
@@ -9119,15 +9119,15 @@ void GenC::writeInterpolatedStringArgBase(const FuExpr * expr)
 		writeTemporaryOrExpr(expr, FuPriority::argument);
 }
 
-void GenC::writeStringPtrAdd(const FuExpr * obj, bool utf8GetString, const std::vector<std::shared_ptr<FuExpr>> * args, bool cast)
+void GenC::writeStringPtrAdd(const FuCallExpr * call, bool cast)
 {
-	if (utf8GetString) {
+	if (isUTF8GetString(call)) {
 		if (cast)
 			write("(const char *) ");
-		writeArrayPtrAdd((*args)[0].get(), (*args)[1].get());
+		writeArrayPtrAdd(call->arguments[0].get(), call->arguments[1].get());
 	}
 	else
-		writeArrayPtrAdd(obj, (*args)[0].get());
+		writeArrayPtrAdd(call->method->left.get(), call->arguments[0].get());
 }
 
 bool GenC::isDictionaryClassStgIndexing(const FuExpr * expr)
@@ -9181,7 +9181,7 @@ void GenC::writeInterpolatedStringArg(const FuExpr * expr)
 	if (call != nullptr) {
 		getStringSubstringLength(call)->accept(this, FuPriority::argument);
 		write(", ");
-		writeStringPtrAdd(call->method->left.get(), isUTF8GetString(call), &call->arguments, true);
+		writeStringPtrAdd(call, true);
 	}
 	else {
 		const FuClassType * klass;
@@ -9723,17 +9723,7 @@ const FuExpr * GenC::getStringSubstringLength(const FuCallExpr * call)
 
 void GenC::writeStringStorageValue(const FuExpr * expr)
 {
-	const FuCallExpr * call = isStringSubstring(expr);
-	if (call != nullptr) {
-		include("string.h");
-		this->stringSubstring = true;
-		write("FuString_Substring(");
-		writeStringPtrAdd(call->method->left.get(), isUTF8GetString(call), &call->arguments, true);
-		write(", ");
-		getStringSubstringLength(call)->accept(this, FuPriority::argument);
-		writeChar(')');
-	}
-	else if (expr->isNewString(false))
+	if (expr->isNewString(false))
 		expr->accept(this, FuPriority::argument);
 	else {
 		include("string.h");
@@ -10501,7 +10491,7 @@ void GenC::writeSubstringEqual(const FuCallExpr * call, std::string_view literal
 		writeChar('(');
 	include("string.h");
 	write("memcmp(");
-	writeStringPtrAdd(call->method->left.get(), isUTF8GetString(call), &call->arguments, false);
+	writeStringPtrAdd(call, false);
 	write(", ");
 	visitLiteralString(literal);
 	write(", ");
@@ -10852,17 +10842,14 @@ void GenC::writeTryParse(const FuExpr * obj, const std::vector<std::shared_ptr<F
 	writeChar(')');
 }
 
-void GenC::writeStringSubstring(const FuExpr * obj, const std::vector<std::shared_ptr<FuExpr>> * args, FuPriority parent)
+void GenC::writeStringSubstringStart(const FuExpr * obj, const std::vector<std::shared_ptr<FuExpr>> * args, FuPriority parent)
 {
-	if (std::ssize(*args) == 1) {
-		if (parent > FuPriority::add)
-			writeChar('(');
-		writeAdd(obj, (*args)[0].get());
-		if (parent > FuPriority::add)
-			writeChar(')');
-	}
-	else
-		notSupported(obj, "Substring");
+	assert(std::ssize(*args) == 1);
+	if (parent > FuPriority::add)
+		writeChar('(');
+	writeAdd(obj, (*args)[0].get());
+	if (parent > FuPriority::add)
+		writeChar(')');
 }
 
 void GenC::startArrayContains(const FuExpr * obj)
@@ -10988,7 +10975,17 @@ void GenC::writeCallExpr(const FuExpr * obj, const FuMethod * method, const std:
 			break;
 		}
 	case FuId::stringSubstring:
-		writeStringSubstring(obj, args, parent);
+		if (std::ssize(*args) == 1)
+			writeStringSubstringStart(obj, args, parent);
+		else {
+			include("string.h");
+			this->stringSubstring = true;
+			write("FuString_Substring(");
+			writeArrayPtrAdd(obj, (*args)[0].get());
+			write(", ");
+			(*args)[1]->accept(this, FuPriority::argument);
+			writeChar(')');
+		}
 		break;
 	case FuId::stringToLower:
 		writeGlib("g_utf8_strdown(");
@@ -11296,6 +11293,15 @@ void GenC::writeCallExpr(const FuExpr * obj, const FuMethod * method, const std:
 		(*args)[0]->accept(this, FuPriority::argument);
 		write("))");
 		break;
+	case FuId::uTF8GetString:
+		include("string.h");
+		this->stringSubstring = true;
+		write("FuString_Substring((const char *) ");
+		writeArrayPtrAdd((*args)[0].get(), (*args)[1].get());
+		write(", ");
+		(*args)[2]->accept(this, FuPriority::argument);
+		writeChar(')');
+		break;
 	case FuId::environmentGetEnvironmentVariable:
 		writeCall("getenv", (*args)[0].get());
 		break;
@@ -12913,7 +12919,10 @@ void GenCl::writeCallExpr(const FuExpr * obj, const FuMethod * method, const std
 			break;
 		}
 	case FuId::stringSubstring:
-		writeStringSubstring(obj, args, parent);
+		if (std::ssize(*args) == 1)
+			writeStringSubstringStart(obj, args, parent);
+		else
+			notSupported(obj, "Substring");
 		break;
 	case FuId::arrayCopyTo:
 		write("for (size_t _i = 0; _i < ");
diff --git a/libfut.cs b/libfut.cs
index 82138a7..dd5e201 100644
--- a/libfut.cs
+++ b/libfut.cs
@@ -9344,15 +9344,15 @@ namespace Fusion
 				WriteTemporaryOrExpr(expr, FuPriority.Argument);
 		}
 
-		void WriteStringPtrAdd(FuExpr obj, bool utf8GetString, List<FuExpr> args, bool cast)
+		void WriteStringPtrAdd(FuCallExpr call, bool cast)
 		{
-			if (utf8GetString) {
+			if (IsUTF8GetString(call)) {
 				if (cast)
 					Write("(const char *) ");
-				WriteArrayPtrAdd(args[0], args[1]);
+				WriteArrayPtrAdd(call.Arguments[0], call.Arguments[1]);
 			}
 			else
-				WriteArrayPtrAdd(obj, args[0]);
+				WriteArrayPtrAdd(call.Method.Left, call.Arguments[0]);
 		}
 
 		static bool IsDictionaryClassStgIndexing(FuExpr expr)
@@ -9405,7 +9405,7 @@ namespace Fusion
 			if (call != null) {
 				GetStringSubstringLength(call).Accept(this, FuPriority.Argument);
 				Write(", ");
-				WriteStringPtrAdd(call.Method.Left, IsUTF8GetString(call), call.Arguments, true);
+				WriteStringPtrAdd(call, true);
 			}
 			else if (expr.Type is FuClassType klass && klass.Class.Id != FuId.StringClass) {
 				Write(this.Namespace);
@@ -10000,17 +10000,7 @@ namespace Fusion
 
 		void WriteStringStorageValue(FuExpr expr)
 		{
-			FuCallExpr call = IsStringSubstring(expr);
-			if (call != null) {
-				Include("string.h");
-				this.StringSubstring = true;
-				Write("FuString_Substring(");
-				WriteStringPtrAdd(call.Method.Left, IsUTF8GetString(call), call.Arguments, true);
-				Write(", ");
-				GetStringSubstringLength(call).Accept(this, FuPriority.Argument);
-				WriteChar(')');
-			}
-			else if (expr.IsNewString(false))
+			if (expr.IsNewString(false))
 				expr.Accept(this, FuPriority.Argument);
 			else {
 				Include("string.h");
@@ -10782,7 +10772,7 @@ namespace Fusion
 				WriteChar('(');
 			Include("string.h");
 			Write("memcmp(");
-			WriteStringPtrAdd(call.Method.Left, IsUTF8GetString(call), call.Arguments, false);
+			WriteStringPtrAdd(call, false);
 			Write(", ");
 			VisitLiteralString(literal);
 			Write(", ");
@@ -11132,17 +11122,14 @@ namespace Fusion
 			WriteChar(')');
 		}
 
-		protected void WriteStringSubstring(FuExpr obj, List<FuExpr> args, FuPriority parent)
+		protected void WriteStringSubstringStart(FuExpr obj, List<FuExpr> args, FuPriority parent)
 		{
-			if (args.Count == 1) {
-				if (parent > FuPriority.Add)
-					WriteChar('(');
-				WriteAdd(obj, args[0]);
-				if (parent > FuPriority.Add)
-					WriteChar(')');
-			}
-			else
-				NotSupported(obj, "Substring");
+			Debug.Assert(args.Count == 1);
+			if (parent > FuPriority.Add)
+				WriteChar('(');
+			WriteAdd(obj, args[0]);
+			if (parent > FuPriority.Add)
+				WriteChar(')');
 		}
 
 		void StartArrayContains(FuExpr obj)
@@ -11264,7 +11251,17 @@ namespace Fusion
 					WriteChar(')');
 				break;
 			case FuId.StringSubstring:
-				WriteStringSubstring(obj, args, parent);
+				if (args.Count == 1)
+					WriteStringSubstringStart(obj, args, parent);
+				else {
+					Include("string.h");
+					this.StringSubstring = true;
+					Write("FuString_Substring(");
+					WriteArrayPtrAdd(obj, args[0]);
+					Write(", ");
+					args[1].Accept(this, FuPriority.Argument);
+					WriteChar(')');
+				}
 				break;
 			case FuId.StringToLower:
 				WriteGlib("g_utf8_strdown(");
@@ -11556,6 +11553,15 @@ namespace Fusion
 				args[0].Accept(this, FuPriority.Argument);
 				Write("))");
 				break;
+			case FuId.UTF8GetString:
+				Include("string.h");
+				this.StringSubstring = true;
+				Write("FuString_Substring((const char *) ");
+				WriteArrayPtrAdd(args[0], args[1]);
+				Write(", ");
+				args[2].Accept(this, FuPriority.Argument);
+				WriteChar(')');
+				break;
 			case FuId.EnvironmentGetEnvironmentVariable:
 				WriteCall("getenv", args[0]);
 				break;
@@ -13171,7 +13177,10 @@ namespace Fusion
 				}
 				break;
 			case FuId.StringSubstring:
-				WriteStringSubstring(obj, args, parent);
+				if (args.Count == 1)
+					WriteStringSubstringStart(obj, args, parent);
+				else
+					NotSupported(obj, "Substring");
 				break;
 			case FuId.ArrayCopyTo:
 				Write("for (size_t _i = 0; _i < ");
diff --git a/libfut.hpp b/libfut.hpp
index 1605e6e..a2f3a0f 100644
--- a/libfut.hpp
+++ b/libfut.hpp
@@ -2079,7 +2079,7 @@ protected:
 	void writeArrayFill(const FuExpr * obj, const std::vector<std::shared_ptr<FuExpr>> * args);
 	void writePrintfNotInterpolated(const std::vector<std::shared_ptr<FuExpr>> * args, bool newLine);
 	void writeCCall(const FuExpr * obj, const FuMethod * method, const std::vector<std::shared_ptr<FuExpr>> * args);
-	void writeStringSubstring(const FuExpr * obj, const std::vector<std::shared_ptr<FuExpr>> * args, FuPriority parent);
+	void writeStringSubstringStart(const FuExpr * obj, const std::vector<std::shared_ptr<FuExpr>> * args, FuPriority parent);
 	void writeCallExpr(const FuExpr * obj, const FuMethod * method, const std::vector<std::shared_ptr<FuExpr>> * args, FuPriority parent) override;
 	void writeIndexingExpr(const FuBinaryExpr * expr, FuPriority parent) override;
 	void writeResource(std::string_view name, int length) override;
@@ -2137,7 +2137,7 @@ private:
 	std::set<FuId> compares;
 	std::set<FuId> contains;
 	std::vector<const FuVar *> varsToDestruct;
-	void writeStringPtrAdd(const FuExpr * obj, bool utf8GetString, const std::vector<std::shared_ptr<FuExpr>> * args, bool cast);
+	void writeStringPtrAdd(const FuCallExpr * call, bool cast);
 	static bool isDictionaryClassStgIndexing(const FuExpr * expr);
 	void writeTemporaryOrExpr(const FuExpr * expr, FuPriority parent);
 	void writeUpcast(const FuClass * resultClass, const FuSymbol * klass);
diff --git a/libfut.js b/libfut.js
index 6e15337..1a5faf7 100644
--- a/libfut.js
+++ b/libfut.js
@@ -9670,15 +9670,15 @@ export class GenC extends GenCCpp
 			this.#writeTemporaryOrExpr(expr, FuPriority.ARGUMENT);
 	}
 
-	#writeStringPtrAdd(obj, utf8GetString, args, cast)
+	#writeStringPtrAdd(call, cast)
 	{
-		if (utf8GetString) {
+		if (GenC.isUTF8GetString(call)) {
 			if (cast)
 				this.write("(const char *) ");
-			this.writeArrayPtrAdd(args[0], args[1]);
+			this.writeArrayPtrAdd(call.arguments_[0], call.arguments_[1]);
 		}
 		else
-			this.writeArrayPtrAdd(obj, args[0]);
+			this.writeArrayPtrAdd(call.method.left, call.arguments_[0]);
 	}
 
 	static #isDictionaryClassStgIndexing(expr)
@@ -9732,7 +9732,7 @@ export class GenC extends GenCCpp
 		if (call != null) {
 			GenC.#getStringSubstringLength(call).accept(this, FuPriority.ARGUMENT);
 			this.write(", ");
-			this.#writeStringPtrAdd(call.method.left, GenC.isUTF8GetString(call), call.arguments_, true);
+			this.#writeStringPtrAdd(call, true);
 		}
 		else {
 			let klass;
@@ -10345,17 +10345,7 @@ export class GenC extends GenCCpp
 
 	#writeStringStorageValue(expr)
 	{
-		let call = GenC.isStringSubstring(expr);
-		if (call != null) {
-			this.include("string.h");
-			this.#stringSubstring = true;
-			this.write("FuString_Substring(");
-			this.#writeStringPtrAdd(call.method.left, GenC.isUTF8GetString(call), call.arguments_, true);
-			this.write(", ");
-			GenC.#getStringSubstringLength(call).accept(this, FuPriority.ARGUMENT);
-			this.writeChar(41);
-		}
-		else if (expr.isNewString(false))
+		if (expr.isNewString(false))
 			expr.accept(this, FuPriority.ARGUMENT);
 		else {
 			this.include("string.h");
@@ -11157,7 +11147,7 @@ export class GenC extends GenCCpp
 			this.writeChar(40);
 		this.include("string.h");
 		this.write("memcmp(");
-		this.#writeStringPtrAdd(call.method.left, GenC.isUTF8GetString(call), call.arguments_, false);
+		this.#writeStringPtrAdd(call, false);
 		this.write(", ");
 		this.visitLiteralString(literal);
 		this.write(", ");
@@ -11517,17 +11507,14 @@ export class GenC extends GenCCpp
 		this.writeChar(41);
 	}
 
-	writeStringSubstring(obj, args, parent)
+	writeStringSubstringStart(obj, args, parent)
 	{
-		if (args.length == 1) {
-			if (parent > FuPriority.ADD)
-				this.writeChar(40);
-			this.writeAdd(obj, args[0]);
-			if (parent > FuPriority.ADD)
-				this.writeChar(41);
-		}
-		else
-			this.notSupported(obj, "Substring");
+		console.assert(args.length == 1);
+		if (parent > FuPriority.ADD)
+			this.writeChar(40);
+		this.writeAdd(obj, args[0]);
+		if (parent > FuPriority.ADD)
+			this.writeChar(41);
 	}
 
 	#startArrayContains(obj)
@@ -11649,7 +11636,17 @@ export class GenC extends GenCCpp
 				this.writeChar(41);
 			break;
 		case FuId.STRING_SUBSTRING:
-			this.writeStringSubstring(obj, args, parent);
+			if (args.length == 1)
+				this.writeStringSubstringStart(obj, args, parent);
+			else {
+				this.include("string.h");
+				this.#stringSubstring = true;
+				this.write("FuString_Substring(");
+				this.writeArrayPtrAdd(obj, args[0]);
+				this.write(", ");
+				args[1].accept(this, FuPriority.ARGUMENT);
+				this.writeChar(41);
+			}
 			break;
 		case FuId.STRING_TO_LOWER:
 			this.#writeGlib("g_utf8_strdown(");
@@ -11943,6 +11940,15 @@ export class GenC extends GenCCpp
 			args[0].accept(this, FuPriority.ARGUMENT);
 			this.write("))");
 			break;
+		case FuId.U_T_F8_GET_STRING:
+			this.include("string.h");
+			this.#stringSubstring = true;
+			this.write("FuString_Substring((const char *) ");
+			this.writeArrayPtrAdd(args[0], args[1]);
+			this.write(", ");
+			args[2].accept(this, FuPriority.ARGUMENT);
+			this.writeChar(41);
+			break;
 		case FuId.ENVIRONMENT_GET_ENVIRONMENT_VARIABLE:
 			this.writeCall("getenv", args[0]);
 			break;
@@ -13592,7 +13598,10 @@ export class GenCl extends GenC
 			}
 			break;
 		case FuId.STRING_SUBSTRING:
-			this.writeStringSubstring(obj, args, parent);
+			if (args.length == 1)
+				this.writeStringSubstringStart(obj, args, parent);
+			else
+				this.notSupported(obj, "Substring");
 			break;
 		case FuId.ARRAY_COPY_TO:
 			this.write("for (size_t _i = 0; _i < ");