Doc: fixed some typo and added some list details

ast.go

@@ -128,6 +128,7 @@ func (self *ast) eval(ctx ExprContext, preset bool) (result any, err error) {
 		}
 		if err == nil {
 			result, err = self.root.compute(ctx)
+			ctx.setVar(ControlLastResult, result)
 		}
 		// } else {
 		// 	err = errors.New("empty expression")

doc/Expr.adoc

@@ -141,7 +141,7 @@ Numbers can be integers (GO int64) or float (GO float64). In mixed operations in
 |=== 
 
 === Fractions
-_Expr_ also suports fractions. Fraction literals are made with tow integers separated by a vertical bar `|`.
+_Expr_ also supports fractions. Fraction literals are made with two integers separated by a vertical bar `|`.
 
 .Examples
 // [source,go]
@@ -149,7 +149,7 @@ _Expr_ also suports fractions. Fraction literals are made with tow integers sepa
 `>>>` [blue]`1 | 2` +
 [green]`1|2` +
 `>>>` [blue]`4|6` +
-[green]`2|3` [gray]_Fractions are always reduced to theri lowest terms_ +
+[green]`2|3` [gray]_Fractions are always reduced to their lowest terms_ +
 `>>>` [blue]`1|2 + 2|3` +
 [green]`7|6` +
 `>>>` [blue]`1|2 * 2|3` +
@@ -245,7 +245,7 @@ Currently, boolean operations are evaluated using _short cut evaluation_. This m
 <1> This multi-expression returns _1_ because in the first expression the left value of [blue]`or` is _true_ and as a conseguence its right value is not computed. Therefore the _a_ variable only receives the integer _1_.
 ====
 
-=== List
+=== Lists
 _Expr_ supports list of mixed-type values, also specified by normal expressions.
 
 .List examples
@@ -258,7 +258,6 @@ _Expr_ supports list of mixed-type values, also specified by normal expressions.
 [ [1,"one"], [2,"two"]]     // List of lists
 ----
 
-
 .List operators
 [cols="^2,^2,5,4"]
 |===
@@ -269,6 +268,34 @@ _Expr_ supports list of mixed-type values, also specified by normal expressions.
 | [blue]`-` | _Difference_ | Left list without elements in the right list  | [blue]`[1,2,3] - [2]` _[ [1,3] ]_
 |===
 
+The items of array can be accessed using the dot `.` operator.
+
+.Item access syntax
+[source,bnf]
+----
+<item> ::= <list-expr>"."<index-expr>
+----
+
+.Items of list
+[source,go]
+----
+`>>>` [blue]`[1,2,3].1`
+[green]`2`
+`>>>` [blue]`list=[1,2,3]; list.1`
+[green]`2`
+`>>>` [blue]`["one","two","three"].1`
+[green]`two`
+`>>>` [blue]`list=["one","two","three"]; list.(2-1)`
+[green]`two`
+`>>>` [blue]`list.(-1)`
+[green]`three`
+`>>>` [blue]`list.(-1)`
+[green]`three`
+`>>>` [blue]`list.(10)`
+----
+
+
+
 == Dictionaries
 The _dictionary_ data-type is set of pairs _key/value_. It is also known as _map_ or _associative array_. Dictionary literals are sequences of pairs separated by comma `,`; sequences are enclosed between brace brackets.
 

func-base.go

@@ -18,6 +18,42 @@ func isNilFunc(ctx ExprContext, name string, args []any) (result any, err error)
 	return
 }
 
+func isIntFunc(ctx ExprContext, name string, args []any) (result any, err error) {
+	result = IsInteger(args[0])
+	return
+}
+
+func isFloatFunc(ctx ExprContext, name string, args []any) (result any, err error) {
+	result = IsFloat(args[0])
+	return
+}
+
+func isBoolFunc(ctx ExprContext, name string, args []any) (result any, err error) {
+	result = IsBool(args[0])
+	return
+}
+
+func isStringFunc(ctx ExprContext, name string, args []any) (result any, err error) {
+	result = IsString(args[0])
+	return
+}
+
+func isFractionFunc(ctx ExprContext, name string, args []any) (result any, err error) {
+	result = IsFract(args[0])
+	return
+}
+
+func isListFunc(ctx ExprContext, name string, args []any) (result any, err error) {
+	result = IsList(args[0])
+	return
+}
+
+func isDictionaryFunc(ctx ExprContext, name string, args []any) (result any, err error) {
+	result = IsDict(args[0])
+	return
+}
+
+
 func intFunc(ctx ExprContext, name string, args []any) (result any, err error) {
 	if len(args) == 1 {
 		switch v := args[0].(type) {
@@ -50,8 +86,17 @@ func iteratorFunc(ctx ExprContext, name string, args []any) (result any, err err
 }
 
 func ImportBuiltinsFuncs(ctx ExprContext) {
-	ctx.RegisterFunc("isNil", &simpleFunctor{f: isNilFunc}, 1, -1)
+	ctx.RegisterFunc("isNil", &simpleFunctor{f: isNilFunc}, 1, 1)
-	ctx.RegisterFunc("int", &simpleFunctor{f: intFunc}, 1, -1)
+	ctx.RegisterFunc("isInt", &simpleFunctor{f: isIntFunc}, 1, 1)
+	ctx.RegisterFunc("isFloat", &simpleFunctor{f: isFloatFunc}, 1, 1)
+	ctx.RegisterFunc("isBool", &simpleFunctor{f: isBoolFunc}, 1, 1)
+	ctx.RegisterFunc("isString", &simpleFunctor{f: isStringFunc}, 1, 1)
+	ctx.RegisterFunc("isFraction", &simpleFunctor{f: isFractionFunc}, 1, 1)
+	ctx.RegisterFunc("isFract", &simpleFunctor{f: isFractionFunc}, 1, 1)
+	ctx.RegisterFunc("isList", &simpleFunctor{f: isListFunc}, 1, 1)
+	ctx.RegisterFunc("isDictionary", &simpleFunctor{f: isDictionaryFunc}, 1, 1)
+	ctx.RegisterFunc("isDict", &simpleFunctor{f: isDictionaryFunc}, 1, 1)
+	ctx.RegisterFunc("int", &simpleFunctor{f: intFunc}, 1, 1)
 }
 
 func init() {

funcs_test.go

@@ -20,7 +20,7 @@ func TestFuncs(t *testing.T) {
 		/*   7 */ {`int(3.9)`, int64(3), nil},
 		/*   8 */ {`int("432")`, int64(432), nil},
 		/*   9 */ {`int("1.5")`, nil, errors.New(`strconv.Atoi: parsing "1.5": invalid syntax`)},
-		/*  10 */ {`int("432", 4)`, nil, errors.New(`int() requires exactly one param`)},
+		/*  10 */ {`int("432", 4)`, nil, errors.New(`too much params -- expected 1, got 2`)},
 		/*  11 */ {`int(nil)`, nil, errors.New(`int() can't convert <nil> to int`)},
 		/*  12 */ {`two=func(){2}; two()`, int64(2), nil},
 		/*  13 */ {`double=func(x) {2*x}; (double(3))`, int64(6), nil},
@@ -54,9 +54,15 @@ func TestFuncs(t *testing.T) {
 		/*  41 */ {`builtin "string"; endsWithStr("0123456789", "xyz", "789")`, true, nil},
 		/*  42 */ {`builtin "string"; endsWithStr("0123456789", "xyz", "0125")`, false, nil},
 		/*  43 */ {`builtin "string"; endsWithStr("0123456789")`, nil, errors.New(`too few params -- expected 2 or more, got 1`)},
-		/*  44 */ {`builtin "string"; splitStr("one-two-three", "-", )`, newListA("one","two","three"), nil},
+		/*  44 */ {`builtin "string"; splitStr("one-two-three", "-", )`, newListA("one", "two", "three"), nil},
-		/*  45 */ {`["a", "b", "c"]`, newListA("a","b","c"), nil},
+		/*  45 */ {`isInt(2+1)`, true, nil},
-		/*  46 */ {`["a", "b", "c"]`, newList([]any{"a","b","c"}), nil},
+		/*  46 */ {`isInt(3.1)`, false, nil},
+		/*  46 */ {`isFloat(3.1)`, true, nil},
+		/*  47 */ {`isString("3.1")`, true, nil},
+		/*  48 */ {`isString("3" + 1)`, true, nil},
+		/*  49 */ {`isList(["3",  1])`, true, nil},
+		/*  50 */ {`isDict({"a":"3",  "b":1})`, true, nil},
+		/*  51 */ {`isFract(3|1)`, true, nil},
 	}
 
 	t.Setenv("EXPR_PATH", ".")

list_test.go

@@ -36,6 +36,9 @@ func TestListParser(t *testing.T) {
 		/*  14 */ {`[1,2,3].1`, int64(2), nil},
 		/*  15 */ {`ls=[1,2,3] but ls.1`, int64(2), nil},
 		/*  16 */ {`ls=[1,2,3] but ls.(-1)`, int64(3), nil},
+		/*  17 */ {`list=["one","two","three"]; list.10`, nil, errors.New(`[1:36] index 10 out of bounds`)},
+		/*  18 */ {`["a", "b", "c"]`, newListA("a", "b", "c"), nil},
+		/*  19 */ {`["a", "b", "c"]`, newList([]any{"a", "b", "c"}), nil},
 
 		// /*  8 */ {`[int(x)|x=csv("test.csv",1,all(),1)]`, []any{int64(10), int64(40), int64(20)}, nil},
 		// /*  9 */ {`sum(@[int(x)|x=csv("test.csv",1,all(),1)])`, []any{int64(10), int64(40), int64(20)}, nil},

operator-dot.go

@@ -22,10 +22,11 @@ func verifyIndex(ctx ExprContext, indexTerm *term, maxValue int) (index int, err
 	var indexValue any
 	if indexValue, err = indexTerm.compute(ctx); err == nil {
 		if v, err = indexTerm.toInt(indexValue, "index expression value must be integer"); err == nil {
+			if v < 0 && v >= -maxValue {
+				v = maxValue + v
+			}
 			if v >= 0 && v < maxValue {
 				index = v
-			} else if index >= -maxValue {
-				index = maxValue + v
 			} else {
 				err = indexTerm.Errorf("index %d out of bounds", v)
 			}

parser_test.go

@@ -177,7 +177,7 @@ func parserTest(t *testing.T, section string, inputs []inputType) {
 		ctx := NewSimpleFuncStore()
 		parser := NewParser(ctx)
 
-		logTest(t, i+1, "Iterator", input.source, input.wantResult, input.wantErr)
+		logTest(t, i+1, section, input.source, input.wantResult, input.wantErr)
 
 		r := strings.NewReader(input.source)
 		scanner := NewScanner(r, DefaultTranslations())

utils.go

@@ -24,6 +24,11 @@ func IsFloat(v any) (ok bool) {
 	return ok
 }
 
+func IsBool(v any) (ok bool) {
+	_, ok = v.(bool)
+	return ok
+}
+
 func IsList(v any) (ok bool) {
 	_, ok = v.(*ListType)
 	return ok
@@ -34,6 +39,11 @@ func IsDict(v any) (ok bool) {
 	return ok
 }
 
+func IsFract(v any) (ok bool) {
+	_, ok = v.(*fraction)
+	return ok
+}
+
 func IsNumber(v any) (ok bool) {
 	return IsFloat(v) || IsInteger(v)
 }