fixed all errors in test files

expr_test.go

@@ -25,8 +25,7 @@ func TestExpr(t *testing.T) {
 	failed := 0
 
 	inputs1 := []inputType{
-		{`f=openFile("/tmp/test2.txt"); line=readFile(f); closeFile(f); line`, "ciao", nil},
-		//{`f = func(op){op()}; f(func(){2})`, int64(2), nil},
+		{`f=openFile("test-file.txt"); line=readFile(f); closeFile(f); line`, "uno", nil},
 	}
 
 	for i, input := range inputs1 {

operand-const.go

@@ -4,52 +4,10 @@
 // operand-const.go
 package expr
 
-// -------- bool const term
-func newBoolTerm(tk *Token) *term {
+// -------- const term
+func newConstTerm(tk *Token) *term {
 	return &term{
 		tk:       *tk,
-		// class:    classConst,
-		// kind:     kindBool,
-		parent:   nil,
-		children: nil,
-		position: posLeaf,
-		priority: priValue,
-		evalFunc: evalConst,
-	}
-}
-
-// -------- integer const term
-func newIntegerTerm(tk *Token) *term {
-	return &term{
-		tk:       *tk,
-		parent:   nil,
-		children: nil,
-		position: posLeaf,
-		priority: priValue,
-		evalFunc: evalConst,
-	}
-}
-
-// -------- float const term
-func newFloatTerm(tk *Token) *term {
-	return &term{
-		tk: *tk,
-		// class:    classConst,
-		// kind:     kindFloat,
-		parent:   nil,
-		children: nil,
-		position: posLeaf,
-		priority: priValue,
-		evalFunc: evalConst,
-	}
-}
-
-// -------- string const term
-func newStringTerm(tk *Token) *term {
-	return &term{
-		tk: *tk,
-		// class:    classConst,
-		// kind:     kindString,
 		parent:   nil,
 		children: nil,
 		position: posLeaf,
@@ -66,8 +24,9 @@ func evalConst(ctx ExprContext, self *term) (v any, err error) {
 
 // init
 func init() {
-	registerTermConstructor(SymString, newStringTerm)
-	registerTermConstructor(SymInteger, newIntegerTerm)
-	registerTermConstructor(SymFloat, newFloatTerm)
-	registerTermConstructor(SymBool, newBoolTerm)
+	registerTermConstructor(SymString, newConstTerm)
+	registerTermConstructor(SymInteger, newConstTerm)
+	registerTermConstructor(SymFloat, newConstTerm)
+	registerTermConstructor(SymBool, newConstTerm)
+	registerTermConstructor(SymKwNil, newConstTerm)
 }

parser_test.go

@@ -63,7 +63,7 @@ func TestParser(t *testing.T) {
 		/*  42 */ {`"s" + true`, nil, errors.New(`[1:6] left operand 's' [string] and right operand 'true' [bool] are not compatible with operator "+"`)},
 		/*  43 */ {`+false`, nil, errors.New(`[1:2] prefix/postfix operator "+" do not support operand 'false' [bool]`)},
 		/*  44 */ {`false // very simple expression`, false, nil},
-		/*  45 */ {`1 + // Missing right operator`, nil, errors.New(`[1:4] infix operator "+" requires two not nil operands, got 1`)},
+		/*  45 */ {`1 + // Missing right operator`, nil, errors.New(`[1:4] infix operator "+" requires two non-nil operands, got 1`)},
 		/*  46 */ {"", nil, errors.New(`empty expression`)},
 		/*  47 */ {"4!", int64(24), nil},
 		/*  48 */ {"(-4)!", nil, errors.New(`factorial of a negative integer (-4) is not allowed`)},
@@ -78,16 +78,16 @@ func TestParser(t *testing.T) {
 		/*  57 */ {`"1.5" > "7"`, false, nil},
 		/*  58 */ {`"1.5" == "7"`, false, nil},
 		/*  59 */ {`"1.5" != "7"`, true, nil},
-		/*  60 */ {"1.5 < ", nil, errors.New(`[1:6] infix operator "<" requires two not nil operands, got 1`)},
-		/*  61 */ {"1.5 > ", nil, errors.New(`[1:6] infix operator ">" requires two not nil operands, got 1`)},
-		/*  62 */ {"1.5 <= ", nil, errors.New(`[1:6] infix operator "<=" requires two not nil operands, got 1`)},
-		/*  63 */ {"1.5 >= ", nil, errors.New(`[1:6] infix operator ">=" requires two not nil operands, got 1`)},
-		/*  64 */ {"1.5 != ", nil, errors.New(`[1:6] infix operator "!=" requires two not nil operands, got 1`)},
-		/*  65 */ {"1.5 == ", nil, errors.New(`[1:6] infix operator "==" requires two not nil operands, got 1`)},
-		/*  66 */ {`"1.5" < `, nil, errors.New(`[1:8] infix operator "<" requires two not nil operands, got 1`)},
-		/*  67 */ {`"1.5" > `, nil, errors.New(`[1:8] infix operator ">" requires two not nil operands, got 1`)},
-		/*  68 */ {`"1.5" == `, nil, errors.New(`[1:8] infix operator "==" requires two not nil operands, got 1`)},
-		/*  69 */ {`"1.5" != `, nil, errors.New(`[1:8] infix operator "!=" requires two not nil operands, got 1`)},
+		/*  60 */ {"1.5 < ", nil, errors.New(`[1:6] infix operator "<" requires two non-nil operands, got 1`)},
+		/*  61 */ {"1.5 > ", nil, errors.New(`[1:6] infix operator ">" requires two non-nil operands, got 1`)},
+		/*  62 */ {"1.5 <= ", nil, errors.New(`[1:6] infix operator "<=" requires two non-nil operands, got 1`)},
+		/*  63 */ {"1.5 >= ", nil, errors.New(`[1:6] infix operator ">=" requires two non-nil operands, got 1`)},
+		/*  64 */ {"1.5 != ", nil, errors.New(`[1:6] infix operator "!=" requires two non-nil operands, got 1`)},
+		/*  65 */ {"1.5 == ", nil, errors.New(`[1:6] infix operator "==" requires two non-nil operands, got 1`)},
+		/*  66 */ {`"1.5" < `, nil, errors.New(`[1:8] infix operator "<" requires two non-nil operands, got 1`)},
+		/*  67 */ {`"1.5" > `, nil, errors.New(`[1:8] infix operator ">" requires two non-nil operands, got 1`)},
+		/*  68 */ {`"1.5" == `, nil, errors.New(`[1:8] infix operator "==" requires two non-nil operands, got 1`)},
+		/*  69 */ {`"1.5" != `, nil, errors.New(`[1:8] infix operator "!=" requires two non-nil operands, got 1`)},
 		/*  70 */ {"+1.5", float64(1.5), nil},
 		/*  71 */ {"+", nil, errors.New(`[1:2] prefix operator "+" requires one not nil operand`)},
 		/*  72 */ {"4 / 0", nil, errors.New(`division by zero`)},
@@ -134,7 +134,7 @@ func TestParser(t *testing.T) {
 		/* 113 */ {`import("test-funcs.expr"); (double(3+a) + 1) * two()`, int64(34), nil},
 		/* 114 */ {`x ?? "default"`, "default", nil},
 		/* 115 */ {`x="hello"; x ?? "default"`, "hello", nil},
-		/* 116 */ {`x ?? func(){}"`, nil, errors.New(`[1:15] the right operand of a coalescing operation cannot be a function definition`)},
+		/* 116 */ {`x ?? func(){}`, nil, errors.New(`[1:14] the right operand of a coalescing operation cannot be a function definition`)},
 		/* 117 */ {`x ?= "default"; x`, "default", nil},
 		/* 118 */ {`x="hello"; x ?= "default"; x`, "hello", nil},
 		/* 119 */ {`@x="hello"; @x`, nil, errors.New(`[1:3] variable references are not allowed in top level expressions: "@x"`)},
@@ -156,6 +156,8 @@ func TestParser(t *testing.T) {
 		/* 135 */ {`10 ? {"a"} :: {"b"} : {"c"}`, nil, errors.New(`[1:22] selector-case outside of a selector context`)},
 		/* 136 */ {`1 ? {"a"} : {"b"} ? ["a"] {"A"} :["b"] {"B"}`, "B", nil},
 		/* 137 */ {`2 + 1 ? {"a"} : {"b"} * 3`, "2bbb", nil},
+		/* 138 */ {`nil`, nil, nil},
+		/* 139 */ {`null`, nil, errors.New(`undefined variable "null"`)},
 	}
 	check_env_expr_path := 113
 

scanner_test.go

@@ -36,7 +36,7 @@ func TestScanner(t *testing.T) {
 		/* 14 */ {`:`, SymColon, nil, nil},
 		/* 15 */ {`;`, SymSemiColon, nil, nil},
 		/* 16 */ {`.`, SymDot, nil, nil},
-		/* 17 */ {`.5`, SymFloat, float64(0.5), nil},
+		/* 17 */ {`0.5`, SymFloat, float64(0.5), nil},
 		/* 18 */ {`\\`, SymBackSlash, nil, nil},
 		/* 19 */ {"`", SymBackTick, nil, nil},
 		/* 20 */ {"?", SymQuestion, nil, nil},
@@ -74,7 +74,7 @@ func TestScanner(t *testing.T) {
 		scanner := NewScanner(r, nil)
 
 		if tk := scanner.Next(); tk == nil {
-			t.Errorf("%d: %q -> got = (nil), want %v (value %v [%T)", i+1, input.source, input.wantSym, input.wantValue, input.wantValue)
+			t.Errorf("%d: %q -> got = (nil), want %v (value %v [%T])", i+1, input.source, input.wantSym, input.wantValue, input.wantValue)
 		} else if tk.Sym != input.wantSym || tk.Value != input.wantValue {
 			if tk.Sym == SymError && input.wantSym == tk.Sym {
 				if tkErr, tkOk := tk.Value.(error); tkOk {

symbol.go

@@ -90,6 +90,7 @@ const (
 	SymKwBut
 	SymKwFunc
 	SymKwBuiltin
+	SymKwNil
 )
 
 var keywords map[string]Symbol
@@ -103,5 +104,6 @@ func init() {
 		"FUNC":    SymKwFunc,
 		"NOT":     SymKwNot,
 		"OR":      SymKwOr,
+		"NIL":     SymKwNil,
 	}
 }

test-file.txt

@@ -0,0 +1,2 @@
+uno
+due

token_test.go

@@ -5,6 +5,7 @@
 package expr
 
 import (
+	"fmt"
 	"testing"
 )
 
@@ -17,8 +18,8 @@ func TestDevString(t *testing.T) {
 	}
 
 	inputs := []inputType{
-		/*   1 */ {"100", SymInteger, 100, `[55]"100"{100}`},
-		/*   2 */ {"+", SymPlus, nil, `[6]"+"{}`},
+		/*   1 */ {"100", SymInteger, 100, fmt.Sprintf(`[%d]"100"{100}`, SymInteger)},
+		/*   2 */ {"+", SymPlus, nil, fmt.Sprintf(`[%d]"+"{}`, SymPlus)},
 	}
 
 	for i, input := range inputs {