Add lexical variable scoping (#13)

README.md

@@ -113,16 +113,16 @@ wt (reverse wjoin wl) each
 #   for (i = 1; i <= NF; i = i + 1) sum = sum + $i
 #   print sum
 # }
-.. (wsplit (toFloat) map sum wl) each
+wt ((toFloat) map sum str wl) each
 
 # 19. Add up all fields in all lines and print the sum
 # { for (i = 1; i <= NF; i = i + 1) sum = sum + $i }
 # END { print sum }
-.. (wsplit (toFloat) map sum) map sum wl
+wt ((toFloat) map sum) sum wl
 
 # 20. Print every line after replacing each field by its absolute value
 # { for (i = 1; i <= NF; i = i + 1) $i = ($i < 0) ? -$i : $i; print }
-.. (wsplit (toFloat abs) map wjoin wl) each
+wt ((toFloat abs) map wjoin wl) each
 
 ```
 

examples/awk/18.awk

@@ -0,0 +1,4 @@
+{ sum = 0
+  for (i = 1; i <= NF; i = i + 1) sum = sum + $i
+  print sum
+}

examples/awk/18.data

@@ -0,0 +1,3 @@
+1 2 3
+4 5 6
+7 8 9

examples/awk/18.msh

@@ -0,0 +1 @@
+wt ((toFloat) map sum str wl) each

examples/awk/test.sh

@@ -44,5 +44,6 @@ emp_test 14
 emp_test 15
 emp_test 16
 emp_test 17
+data_test 18
 
 exit "$FAIL"

lib/std.msh

@@ -6,9 +6,11 @@ def each
     0 each-idx! # index
     (
         [(@each-idx @each-len >=) (break)] if
+        # "Each idx: " w @each-idx w " Each len: " w @each-len wl
         over @each-idx nth # Get current item
-        over x # Copy over quote, execute
+        over x  # Copy over quote, execute
         @each-idx 1 + each-idx! # inc index
+        # "Each idx: " w @each-idx wl
     ) loop
 
     # Drop list and quote, total length, index

mshell/Evaluator.go

@@ -48,7 +48,6 @@ func (objList *MShellStack) String() string {
 type EvalState struct {
 	PositionalArgs []string
 	LoopDepth      int
-	Variables      map[string]MShellObject
 
 	StopOnError bool
 }
@@ -62,6 +61,7 @@ type EvalResult struct {
 type ExecuteContext struct {
 	StandardInput  io.Reader
 	StandardOutput io.Writer
+    Variables      map[string]MShellObject
 }
 
 func SimpleSuccess() EvalResult {
@@ -103,7 +103,7 @@ MainLoop:
 			stack.Push(&MShellList{Items: listStack, StandardInputFile: "", StandardOutputFile: "", StdoutBehavior: STDOUT_NONE})
 		case *MShellParseQuote:
 			parseQuote := t.(*MShellParseQuote)
-			q := MShellQuotation{Tokens: parseQuote.Items, StandardInputFile: "", StandardOutputFile: "", StandardErrorFile: ""}
+            q := MShellQuotation{Tokens: parseQuote.Items, StandardInputFile: "", StandardOutputFile: "", StandardErrorFile: "", Variables: context.Variables}
 			stack.Push(&q)
 		case Token:
 			t := t.(Token)
@@ -116,7 +116,13 @@ MainLoop:
 				for _, definition := range definitions {
 					if definition.Name == t.Lexeme {
 						// Evaluate the definition
-						result := state.Evaluate(definition.Items, stack, context, definitions)
+
+                        var newContext ExecuteContext
+                        newContext.Variables = make(map[string]MShellObject)
+                        newContext.StandardInput = context.StandardInput
+                        newContext.StandardOutput = context.StandardOutput
+
+						result := state.Evaluate(definition.Items, stack, newContext, definitions)
 						if !result.Success || result.BreakNum > 0 {
 							return result
 						}
@@ -661,7 +667,7 @@ MainLoop:
                         return FailWithMessage(fmt.Sprintf("%d:%d: Error setting OLDPWD: %s\n", t.Line, t.Column, err.Error()))
                     }
 
-                    state.Variables["OLDPWD"] = &MShellString{oldPwd}
+                    context.Variables["OLDPWD"] = &MShellString{oldPwd}
 
                     err = os.Chdir(dir)
                     if err != nil {
@@ -679,7 +685,7 @@ MainLoop:
                         return FailWithMessage(fmt.Sprintf("%d:%d: Error setting PWD: %s\n", t.Line, t.Column, err.Error()))
                     }
 
-                    state.Variables["PWD"] = &MShellString{pwd}
+                    context.Variables["PWD"] = &MShellString{pwd}
                 } else if t.Lexeme == "in" {
                     substring, err := stack.Pop()
                     if err != nil {
@@ -916,9 +922,20 @@ MainLoop:
 					switch obj2.(type) {
 					case *MShellInt:
 						stack.Push(&MShellInt{obj2.(*MShellInt).Value + obj1.(*MShellInt).Value})
+                    case *MShellFloat:
+                        stack.Push(&MShellFloat{float64(obj2.(*MShellFloat).Value) + float64(obj1.(*MShellInt).Value)})
 					default:
 						return FailWithMessage(fmt.Sprintf("%d:%d: Cannot add an integer to a %s.\n", t.Line, t.Column, obj2.TypeName()))
 					}
+                case *MShellFloat:
+                    switch obj2.(type) {
+                    case *MShellFloat:
+                        stack.Push(&MShellFloat{obj2.(*MShellFloat).Value + obj1.(*MShellFloat).Value})
+                    case *MShellInt:
+                        stack.Push(&MShellFloat{float64(obj2.(*MShellInt).Value) + obj1.(*MShellFloat).Value})
+                    default:
+                        return FailWithMessage(fmt.Sprintf("%d:%d: Cannot add a float to a %s.\n", t.Line, t.Column, obj2.TypeName()))
+                    }
 				case *MShellString:
 					switch obj2.(type) {
 					case *MShellString:
@@ -946,7 +963,7 @@ MainLoop:
                         stack.Push(newList)
                     }
 				default:
-					return FailWithMessage(fmt.Sprintf("%d:%d: Cannot apply '+' to a %s to a %s.\n", t.Line, t.Column, obj2.TypeName(), obj1.TypeName()))
+					return FailWithMessage(fmt.Sprintf("%d:%d: Cannot apply '+' between a %s and a %s.\n", t.Line, t.Column, obj2.TypeName(), obj1.TypeName()))
 				}
 			} else if t.Type == MINUS {
 				obj1, err := stack.Pop()
@@ -1130,10 +1147,10 @@ MainLoop:
 					return FailWithMessage(fmt.Sprintf("%d:%d: Nothing on stack to store into variable %s.\n", t.Line, t.Column, varName))
 				}
 
-				state.Variables[varName] = obj
+				context.Variables[varName] = obj
 			} else if t.Type == VARRETRIEVE {
 				name := t.Lexeme[1:] // Remove the leading @
-				obj, found_mshell_variable := state.Variables[name]
+				obj, found_mshell_variable := context.Variables[name]
 				if found_mshell_variable {
 					stack.Push(obj)
 				} else {
@@ -1145,7 +1162,7 @@ MainLoop:
 						var message strings.Builder
 						message.WriteString(fmt.Sprintf("%d:%d: Variable %s not found.\n", t.Line, t.Column, name))
 						message.WriteString("Variables:\n")
-						for key := range state.Variables {
+						for key := range context.Variables {
 							message.WriteString(fmt.Sprintf("  %s\n", key))
 						}
 						return FailWithMessage(message.String())
@@ -1166,17 +1183,18 @@ MainLoop:
 					return FailWithMessage(fmt.Sprintf("%d:%d: Loop quotation needs a minimum of one token.\n", t.Line, t.Column))
 				}
 
-				context := ExecuteContext{
+				loopContext := ExecuteContext{
 					StandardInput:  nil,
 					StandardOutput: nil,
+                    Variables: context.Variables,
 				}
 
 				if quotation.StandardInputFile != "" {
 					file, err := os.Open(quotation.StandardInputFile)
 					if err != nil {
 						return FailWithMessage(fmt.Sprintf("%d:%d: Error opening file %s for reading: %s\n", t.Line, t.Column, quotation.StandardInputFile, err.Error()))
 					}
-					context.StandardInput = file
+					loopContext.StandardInput = file
 					defer file.Close()
 				}
 
@@ -1185,7 +1203,7 @@ MainLoop:
 					if err != nil {
 						return FailWithMessage(fmt.Sprintf("%d:%d: Error opening file %s for writing: %s\n", t.Line, t.Column, quotation.StandardOutputFile, err.Error()))
 					}
-					context.StandardOutput = file
+					loopContext.StandardOutput = file
 					defer file.Close()
 				}
 
@@ -1196,7 +1214,7 @@ MainLoop:
 				breakDiff := 0
 
 				for loopCount < maxLoops {
-					result := state.Evaluate(quotation.Tokens, stack, context, definitions)
+					result := state.Evaluate(quotation.Tokens, stack, loopContext, definitions)
 
 					if !result.Success {
 						return result
@@ -1297,6 +1315,7 @@ MainLoop:
 					// Default to stdout of this process itself
 					quoteContext.StandardOutput = os.Stdout
 				}
+                quoteContext.Variables = quotation.Variables
 
 				result := state.Evaluate(quotation.Tokens, stack, quoteContext, definitions)
 				if !result.Success {
@@ -1548,9 +1567,9 @@ MainLoop:
 				}
 
 				// Check that varName is in state.Variables, and varName is string or literal
-				varValue, ok := state.Variables[varName]
+				varValue, ok := context.Variables[varName]
 				if !ok {
-					return FailWithMessage(fmt.Sprintf("%d:%d: Variable %s not found in state.Variables.\n", t.Line, t.Column, varName))
+					return FailWithMessage(fmt.Sprintf("%d:%d: Variable %s not found in available variables.\n", t.Line, t.Column, varName))
 				}
 
 				switch varValue.(type) {
@@ -1596,6 +1615,7 @@ func (quotation *MShellQuotation) Execute(state *EvalState, context ExecuteConte
 	quotationContext := ExecuteContext{
 		StandardInput:  nil,
 		StandardOutput: nil,
+        Variables:      quotation.Variables,
 	}
 
 	if quotation.StandardInputFile != "" {
@@ -1800,6 +1820,7 @@ func (state *EvalState) RunPipeline(MShellPipe MShellPipe, context ExecuteContex
 		newContext := ExecuteContext{
 			StandardInput:  nil,
 			StandardOutput: nil,
+            Variables:      context.Variables,
 		}
 
 		if i == 0 {

mshell/MShellObject.go

@@ -43,6 +43,7 @@ type MShellQuotation struct {
 	StandardInputFile  string
 	StandardOutputFile string
 	StandardErrorFile  string
+    Variables          map[string]MShellObject
 }
 
 // type MShellQuotation2 struct {

mshell/Main.go

@@ -108,14 +108,14 @@ func main() {
 	state := EvalState{
 		PositionalArgs: positionalArgs,
 		LoopDepth:      0,
-		Variables:      make(map[string]MShellObject),
 	}
 
 	var stack MShellStack
 	stack = []MShellObject{}
 	context := ExecuteContext{
 		StandardInput:  os.Stdin,
 		StandardOutput: os.Stdout,
+        Variables: map[string]MShellObject{},
 	}
 
 	var allDefinitions []MShellDefinition

tests/indexing.msh.stdout

@@ -14,3 +14,4 @@ a, b, x, c, d
 a, b, c, x, d
 a, b, x, d
 a, b, c, x
+d, c, b, a