Merge pull request #577 from chris-a-talbot/add-readLine-eidos

Add readLine() to Eidos - resolves issue #576

Author: bhaller

eidos/eidos_functions.cpp

@@ -369,6 +369,7 @@ const std::vector<EidosFunctionSignature_CSP> &EidosInterpreter::BuiltInFunction
 		signatures->emplace_back((EidosFunctionSignature *)(new EidosFunctionSignature("fileExists",		Eidos_ExecuteFunction_fileExists,	kEidosValueMaskLogical | kEidosValueMaskSingleton))->AddString_S(gEidosStr_filePath));
 		signatures->emplace_back((EidosFunctionSignature *)(new EidosFunctionSignature("flushFile",			Eidos_ExecuteFunction_flushFile,	kEidosValueMaskLogical | kEidosValueMaskSingleton))->AddString_S(gEidosStr_filePath));
 		signatures->emplace_back((EidosFunctionSignature *)(new EidosFunctionSignature("readFile",			Eidos_ExecuteFunction_readFile,		kEidosValueMaskString))->AddString_S(gEidosStr_filePath));
+		signatures->emplace_back((EidosFunctionSignature *)(new EidosFunctionSignature("readLine",			Eidos_ExecuteFunction_readLine,		kEidosValueMaskString | kEidosValueMaskSingleton)));
 		signatures->emplace_back((EidosFunctionSignature *)(new EidosFunctionSignature("setwd",				Eidos_ExecuteFunction_setwd,		kEidosValueMaskString | kEidosValueMaskSingleton))->AddString_S("path"));
 		signatures->emplace_back((EidosFunctionSignature *)(new EidosFunctionSignature("tempdir",			Eidos_ExecuteFunction_tempdir,		kEidosValueMaskString | kEidosValueMaskSingleton)));
 		signatures->emplace_back((EidosFunctionSignature *)(new EidosFunctionSignature("writeFile",			Eidos_ExecuteFunction_writeFile,	kEidosValueMaskLogical | kEidosValueMaskSingleton))->AddString_S(gEidosStr_filePath)->AddString("contents")->AddLogical_OS("append", gStaticEidosValue_LogicalF)->AddLogical_OS("compress", gStaticEidosValue_LogicalF));

eidos/eidos_functions.h

@@ -250,6 +250,7 @@ EidosValue_SP Eidos_ExecuteFunction_filesAtPath(const std::vector<EidosValue_SP>
 EidosValue_SP Eidos_ExecuteFunction_flushFile(const std::vector<EidosValue_SP> &p_arguments, EidosInterpreter &p_interpreter);
 EidosValue_SP Eidos_ExecuteFunction_getwd(const std::vector<EidosValue_SP> &p_arguments, EidosInterpreter &p_interpreter);
 EidosValue_SP Eidos_ExecuteFunction_readFile(const std::vector<EidosValue_SP> &p_arguments, EidosInterpreter &p_interpreter);
+EidosValue_SP Eidos_ExecuteFunction_readLine(const std::vector<EidosValue_SP> &p_arguments, EidosInterpreter &p_interpreter);
 EidosValue_SP Eidos_ExecuteFunction_setwd(const std::vector<EidosValue_SP> &p_arguments, EidosInterpreter &p_interpreter);
 EidosValue_SP Eidos_ExecuteFunction_tempdir(const std::vector<EidosValue_SP> &p_arguments, EidosInterpreter &p_interpreter);
 EidosValue_SP Eidos_ExecuteFunction_writeFile(const std::vector<EidosValue_SP> &p_arguments, EidosInterpreter &p_interpreter);

eidos/eidos_functions_files.cpp

@@ -27,7 +27,9 @@
 #include <stdio.h>
 #include <dirent.h>
 #include <fstream>
+#include <iostream>
 #include <sys/stat.h>
+#include <unistd.h>
 
 #include "../eidos_zlib/zlib.h"
 
@@ -220,6 +222,40 @@ EidosValue_SP Eidos_ExecuteFunction_readFile(const std::vector<EidosValue_SP> &p
 	return result_SP;
 }
 
+//	(string$)readLine(void)
+EidosValue_SP Eidos_ExecuteFunction_readLine(const std::vector<EidosValue_SP> &p_arguments, EidosInterpreter &p_interpreter)
+{
+#pragma unused (p_arguments)
+	
+#ifdef EIDOS_GUI
+	EIDOS_TERMINATION << "ERROR (Eidos_ExecuteFunction_readLine): function readLine() is not available in GUI environments (SLiMgui, SLiMguiLegacy, or EidosScribe)." << EidosTerminate(nullptr);
+#endif
+
+	// This function was implemented by Chris Talbot 11/19/25 for use in reinforcement learning environments.
+	// Associated with issue #576.
+	
+	EidosValue_SP result_SP(nullptr);
+	
+	// Read a single line from stdin (command-line mode with interactive terminal)
+	std::string line;
+	
+	if (std::getline(std::cin, line))
+	{
+		// Control for CRLF vs. LF line endings
+		if (!line.empty() && line[line.size() - 1] == '\r')
+			line.pop_back();
+		
+		result_SP = EidosValue_SP(new (gEidosValuePool->AllocateChunk()) EidosValue_String(line));
+	}
+	else
+	{
+		// EOF or error reading from stdin; return empty string
+		result_SP = EidosValue_SP(new (gEidosValuePool->AllocateChunk()) EidosValue_String(""));
+	}
+	
+	return result_SP;
+}
+
 //	(string$)setwd(string$ path)
 EidosValue_SP Eidos_ExecuteFunction_setwd(const std::vector<EidosValue_SP> &p_arguments, __attribute__((unused)) EidosInterpreter &p_interpreter)
 {