add float support to scanner/parser for arguments

pql/parser.go

@@ -174,6 +174,12 @@ func (p *Parser) parseArgs() (map[string]interface{}, error) {
 				return nil, err
 			}
 			value = v
+		case FLOAT:
+			v, err := strconv.ParseFloat(lit, 64)
+			if err != nil {
+				return nil, err
+			}
+			value = v
 		case LBRACK:
 			v, err := p.parseList()
 			if err != nil {

pql/parser_test.go

@@ -80,6 +80,24 @@ func TestParser_Parse(t *testing.T) {
 		}
 	})
 
+	// Parse with float arguments.
+	t.Run("WithFloatArgs", func(t *testing.T) {
+		q, err := pql.ParseString(`MyCall( key=12.25, foo= 13.167)`)
+		if err != nil {
+			t.Fatal(err)
+		} else if !reflect.DeepEqual(q.Calls[0],
+			&pql.Call{
+				Name: "MyCall",
+				Args: map[string]interface{}{
+					"key": 12.25,
+					"foo": 13.167,
+				},
+			},
+		) {
+			t.Fatalf("unexpected call: %#v", q.Calls[0])
+		}
+	})
+
 	// Parse with both child calls and arguments.
 	t.Run("ChildrenAndArguments", func(t *testing.T) {
 		q, err := pql.ParseString(`TopN(Bitmap(id=100, frame=other), frame=f, n=3)`)

pql/scanner.go

@@ -143,17 +143,23 @@ func (s *Scanner) scanIdent() (tok Token, pos Pos, lit string) {
 // scanNumber consumes consecutive integer digits.
 func (s *Scanner) scanNumber() (tok Token, pos Pos, lit string) {
 	pos = s.pos
+	tok = NUMBER
 
 	var buf bytes.Buffer
+	var seenDot bool
 	for {
 		ch := s.read()
-		if !isDigit(ch) {
+		if !isDigit(ch) && (seenDot || ch != '.') {
 			s.unread()
 			break
 		}
+		if ch == '.' {
+			seenDot = true
+			tok = FLOAT
+		}
 		buf.WriteRune(ch)
 	}
-	return NUMBER, pos, buf.String()
+	return tok, pos, buf.String()
 }
 
 // scanString consumes a single-quoted or double-quoted string.

pql/scanner_test.go

@@ -30,6 +30,7 @@ func TestScanner_Scan(t *testing.T) {
 
 		{s: `foo`, tok: pql.IDENT, lit: `foo`},
 		{s: `100`, tok: pql.NUMBER, lit: `100`},
+		{s: `100.3`, tok: pql.FLOAT, lit: `100.3`},
 
 		{s: `all`, tok: pql.ALL, lit: `all`},
 		{s: `ALL`, tok: pql.ALL, lit: `ALL`}, // case insensitive

pql/token.go

@@ -16,6 +16,7 @@ const (
 	STRING    // "foo"
 	BADSTRING // bad escape or unclosed string
 	NUMBER    // 12345
+	FLOAT     // 100.2
 	literal_end
 
 	keyword_beg