Implement LAMBDA and LAMBDAP (#2168), verified.

Co-authored-by: Giloo <gildas@localhost>

Author: GillesDuvert

src/GDLInterpreter.cpp

@@ -415,15 +415,15 @@ GDLInterpreter::GDLInterpreter()
 	}
 	catch ( GDLException& e) {
 
-		// errors while typing commands in inner loop (called via Control-C, STOP, error) should be ignored.
-		if (e.Interpreter()->IsInnerInterpreterLoop()) {
-		  e.Interpreter()->SetInnerInterpeterLoop(false);
-		  _retTree=NULL;
-		  debugMode=DEBUG_CLEAR;
-		  // we cannot throw, here, it caused #2017 
-		  Warning(e.getMessage());  //just warn that there was a (typing ?) error see #1855
-		return RC_OK;
-		}
+				// errors while typing commands in inner loop (called via Control-C, STOP, error) should be ignored.
+				if (e.Interpreter()->IsInnerInterpreterLoop()) {
+				  e.Interpreter()->SetInnerInterpeterLoop(false);
+				  _retTree=NULL;
+				  debugMode=DEBUG_CLEAR;
+				  // we cannot throw, here, it caused #2017 
+				  Warning(e.getMessage());  //just warn that there was a (typing ?) error see #1855
+				return RC_OK;
+				}
 			// reset _retTree to last statement
 			// (might otherwise be inside an expression in which case 
 			// .CONTINUE does not work)

src/GDLInterpreter.hpp

@@ -178,7 +178,8 @@ class CUSTOM_API GDLInterpreter : public antlr::TreeParser, public GDLInterprete
     // procedure (searchForPro == true) or function (searchForPro == false)
     static bool CompileFile(const std::string& f, 
 			    const std::string& untilPro="",
-			    bool searchForPro=true); 
+			    bool searchForPro=true,
+				bool inlined=false); 
     static bool CompileSaveFile(RefDNode theAST); 
     typedef RefHeap<BaseGDL> RefBaseGDL;
     typedef RefHeap<DStructGDL> RefDStructGDL;

src/basic_fun.cpp

@@ -1603,7 +1603,88 @@ namespace lib {
     }
     return int_fun(e);
   }
+// LAMBDAS
+static  std::map<unsigned int, int> lambdaFunMemory;
+static  std::map<unsigned int, int> lambdaProMemory;
+  
+//deemed dangerous, but should be enough to uniquely identify if 2 lambdas are the same  
+unsigned int JSHash(const std::string& str)
+ {
+      unsigned int hash = 1315423911;
 
+      for(std::size_t i = 0; i < str.length(); i++)
+      {
+          hash ^= ((hash << 5) + str[i] + (hash >> 2));
+      }
+
+      return (hash & 0x7FFFFFFF);
+ }
+
+  BaseGDL* lambda_fun(EnvT* e) {
+    static const std::string EOL("\n");
+    static int lambdanum=1;
+    DStringGDL* GDLexpr = e->GetParAs<DStringGDL>(0);
+    DString expr=(*GDLexpr)[0];
+    unsigned int hash=JSHash(expr);
+    std::map<unsigned int,int>::iterator it;
+    it = lambdaFunMemory.find(hash);
+    if (it != lambdaFunMemory.end()) return new DStringGDL("IDL$LAMBDAF"+i2s((*it).second));
+
+    size_t pos=expr.find(":",0);
+    if (pos==std::string::npos) e->Throw("Code must be of the form \"arg1,arg2,... : statement\"");
+    std::string arguments=expr.substr(0,pos);
+    string lambdaFunName="IDL$LAMBDAF"+i2s(lambdanum);
+    std::string functionText;
+    functionText+="FUNCTION ";
+    functionText+=lambdaFunName;
+    functionText+=",";
+    functionText+=arguments;
+    functionText+=EOL;
+    functionText+="COMPILE_OPT IDL2, hidden\nRETURN,";
+    functionText+=expr.substr(pos+1);
+    functionText+=EOL;
+    functionText+="END";
+    bool ok=GDLInterpreter::CompileFile(functionText,"", false, true);
+    if (!ok) e->Throw("Syntax error in code.");
+
+    lambdaFunMemory.insert(std::pair<unsigned int,int>(hash,lambdanum));
+    lambdanum++;
+    return new DStringGDL(lambdaFunName);
+  }
+  
+   BaseGDL* lambda_pro(EnvT* e) {
+    static const std::string EOL("\n");
+    static int lambdanum=1;
+    DStringGDL* GDLexpr = e->GetParAs<DStringGDL>(0);
+    DString expr=(*GDLexpr)[0];
+    unsigned int hash=JSHash(expr);
+    std::map<unsigned int,int>::iterator it;
+    it = lambdaProMemory.find(hash);
+    if (it != lambdaProMemory.end()) return new DStringGDL("IDL$LAMBDAP"+i2s((*it).second));
+
+    size_t pos=expr.find(":",0);
+    if (pos==std::string::npos) e->Throw("Code must be of the form \"arg1,arg2,... : statement\"");
+    std::string arguments=expr.substr(0,pos);
+    string lambdaProName="IDL$LAMBDAP"+i2s(lambdanum);
+    std::string proText;
+    proText+="PRO ";
+    proText+=lambdaProName;
+    proText+=",";
+    proText+=arguments;
+    proText+=EOL;
+    proText+="COMPILE_OPT IDL2, hidden";
+    proText+=EOL;
+    proText+=expr.substr(pos+1);
+    proText+=EOL;
+    proText+="END";
+    bool ok=GDLInterpreter::CompileFile(proText,"", false, true);
+    if (!ok) e->Throw("Syntax error in code.");
+    
+    lambdaProMemory.insert(std::pair<unsigned int,int>(hash,lambdanum));
+    lambdanum++;
+    return new DStringGDL(lambdaProName);
+  }
+   
   BaseGDL* call_function(EnvT* e) {
     int nParam = e->NParam();
     if (nParam == 0)

src/basic_fun.hpp

@@ -179,7 +179,9 @@ namespace lib {
   BaseGDL** scope_varfetch_reference( EnvT* e); // special version for LEval()
   BaseGDL* scope_varname_fun( EnvT* e);
   BaseGDL* mean_fun(EnvT* e); 
-  BaseGDL* moment_fun(EnvT* e); 
+  BaseGDL* moment_fun(EnvT* e);
+  BaseGDL* lambda_fun(EnvT* e);
+  BaseGDL* lambda_pro(EnvT* e);
 } // namespace
 
 #endif

src/dinterpreter.cpp

@@ -644,14 +644,16 @@ void GDLInterpreter::ReportCompileError( GDLException& e, const string& file)
 // compiles file, returns success
 // if untilPro is set to "" the whole file is compiled
 // procedure (searchForPro == true (default)) or function (searchForPro == false)
-bool GDLInterpreter::CompileFile(const string& f, const string& untilPro, bool searchForPro) 
+bool GDLInterpreter::CompileFile(const string& f, const string& untilPro, bool searchForPro, bool inlined) 
 {
-  ifstream in(f.c_str());
-  if( !in) return false; // maybe throw exception here
-  
+//Note that std::unique_ptr is better that raw pointers
+std::unique_ptr<std::istream> stream;
+//stream holds a string
+if (inlined) stream = std::make_unique<std::istringstream>(f); else stream = std::make_unique<std::ifstream>(std::ifstream{ f.c_str() });
+
   RefDNode theAST;
   try {  
-    GDLLexer   lexer(in, f, GDLParser::NONE, untilPro, searchForPro);
+    GDLLexer   lexer(*stream, f, GDLParser::NONE, untilPro, searchForPro);
     GDLParser& parser=lexer.Parser();
 
     // parsing

src/dpro.hpp

@@ -631,6 +631,9 @@ typedef std::vector<DPro*> ProListT;
 typedef std::set<std::string> UnknownFunListT;
 typedef std::set<std::string> UnknownProListT;
 
+typedef std::map<std::string, DFun*> LambdaFunListT;
+typedef std::map<std::string, DPro*> LambdaProListT;
+
 typedef std::vector<DLibFun*> LibFunListT;
 typedef std::vector<DLibPro*> LibProListT;
 

src/gdlc.i.g

@@ -231,7 +231,8 @@ public:
     // procedure (searchForPro == true) or function (searchForPro == false)
     static bool CompileFile(const std::string& f, 
 			    const std::string& untilPro="",
-			    bool searchForPro=true); 
+			    bool searchForPro=true,
+				bool inlined=false); 
     static bool CompileSaveFile(RefDNode theAST); 
     typedef RefHeap<BaseGDL> RefBaseGDL;
     typedef RefHeap<DStructGDL> RefDStructGDL;

src/libinit.cpp

@@ -113,6 +113,9 @@ void LibInit()
   new DLibFunRetNew(lib::orderedhash_fun,string("ORDEREDHASH"),-1,hashKey);
 
   new DLibFun(lib::scope_level,string("SCOPE_LEVEL"),0);
+  //LAMBDA function
+  new DLibFun(lib::lambda_fun,string("LAMBDA"),1);
+  new DLibFun(lib::lambda_pro,string("LAMBDAP"),1);
 
   //SCOPE_VARFETCH WARNING: changes in lib::scope_varfetch_value must be reported also in lib::scope_varfetch_reference
   const string scope_varfetchKey[]={"LEVEL","ENTER", "REF_EXTRA", "COMMON", KLISTEND};

src/objects.cpp

@@ -1022,13 +1022,8 @@ bool IsPro(antlr::RefToken rT1)
 {
   antlr::Token& T1=*rT1;
 
-  // search for T1.getText() in function table and path
   string searchName=StrUpCase(T1.getText());
 
-//  cout << "IsFun: Searching for: " << searchName << endl;
-
-// Speeds up the process of finding (in gdlc.g) if a syntax like foo(bar) is a call to the function 'foo'
-// or the 'bar' element of array 'foo'.
   LibProListT::iterator p=find_if(libProList.begin(),libProList.end(),
 			       Is_eq<DLibPro>(searchName));
   if( p != libProList.end()) if( *p != NULL) return true;
@@ -1041,9 +1036,6 @@ bool IsPro(antlr::RefToken rT1)
   for ( UnknownProListT::iterator r=unknownProList.begin(); r!=unknownProList.end(); ++r) {
     if( (*r) == searchName )  return true;
   }
-
-  //  cout << "Not found: " << searchName << endl;
-
   return false;
 }
 
@@ -1052,14 +1044,44 @@ int ProIx(const string& n)
 SizeT nF=proList.size();
 for( SizeT i=0; i<nF; i++) if( Is_eq<DPro>(n)(proList[i])) 
   return (int)i;
-return -1;
-}
+  //may be a lambda list ? so it's a UD Pro
+  EnvT* requestedScope = (EnvT*) DInterpreter::CallStackBack();
+  DSubUD* pro = static_cast<DSubUD*> (requestedScope->GetPro());
+  int xI = pro->FindVar(n);
+  if (xI != -1) {
+    BaseGDL*& var = requestedScope->GetTheKW(xI);
+    if (var == NULL) return -1;
+    if (var->N_Elements() != 1) return -1;
+    if (var->Type() == GDL_STRING) { //examine string
+      DString *s = static_cast<DString*> (var->DataAddr());
+      if (s->find("IDL$LAMBDAP", 0) == 0) { //is a lambda
+        for (SizeT i = 0; i < nF; i++) if (Is_eq<DPro>(*s)(proList[i])) return (int) i;
+      }
+    }
+  }
+  return -1;
+ }
 
 int FunIx(const string& n)
 {
 SizeT nF=funList.size();
 for( SizeT i=0; i<nF; i++) if( Is_eq<DFun>(n)(funList[i]))
   return (int)i;
+//may be a lambda list ? so it's a UD Fun
+    EnvT* requestedScope = (EnvT*) DInterpreter::CallStackBack();
+    DSubUD* pro = static_cast<DSubUD*> (requestedScope->GetPro());
+    int xI = pro->FindVar(n);
+    if (xI != -1) {
+      BaseGDL*& var = requestedScope->GetTheKW(xI);
+      if (var == NULL) return -1;
+      if (var->N_Elements() !=1) return -1;
+      if (var->Type() == GDL_STRING) { //examine string
+        DString *s=static_cast<DString*>(var->DataAddr());
+        if (s->find("IDL$LAMBDAF",0)==0) { //is a lambda
+          for( SizeT i=0; i<nF; i++) if( Is_eq<DFun>(*s)(funList[i])) return (int)i;
+        }
+      }
+    }
 return -1;
 }
 
@@ -1069,7 +1091,7 @@ int LibProIx(const string& n)
   for( SizeT i=0; i<nF; i++) 
     {
       if( Is_eq<DLibPro>(n)(libProList[i])) return (int)i;
-    }
+  }
   return -1;
 }
 

testsuite/LIST

@@ -121,6 +121,7 @@ test_l64.pro
 test_la_least_squares.pro
 test_la_trired.pro
 test_label_date.pro
+test_lambdas.pro
 test_linfit.pro
 test_list.pro
 test_ludc_lusol.pro