add boolean type

cmd/moon/main.go

@@ -24,6 +24,15 @@ The following is taken to be the contents of a file named ex.moon:
   first_name: jordan
   last_name: orelli
 
+  # the bare strings true and false are boolean values
+  bool_true: true
+  bool_false: false
+
+  # the quoted strings "true" and "false" are string values.  In the unlikely
+  # event you need literal true and false strings, quote them.
+  string_true: "true"
+  string_false: "false"
+
   # lists of things should be supported
   items: [
       one
@@ -66,7 +75,6 @@ The following is taken to be the contents of a file named ex.moon:
 
   people: [@person_one @person_two]
 
-
 Subcommands
 
 check:  used to syntax check a given file.  To check a given file, in this case ex.moon, to see if it is syntactically valid, one would invoke the following command:

ex.moon

@@ -12,6 +12,15 @@
 first_name: jordan
 last_name: orelli
 
+# the bare strings true and false are boolean values
+bool_true: true
+bool_false: false
+
+# the quoted strings "true" and "false" are string values.  In the unlikely
+# event you need literal true and false strings, quote them.
+string_true: "true"
+string_false: "false"
+
 # lists of things should be supported
 items: [
     one

lib/doc.go

@@ -89,28 +89,7 @@ func setValue(dest, src reflect.Value) error {
 		dest.Set(src)
 		return nil
 	}
-	switch dest.Kind() {
-	case reflect.Bool:
-		setBoolValue(dest, src)
-		return nil
-	default:
-		return fmt.Errorf("src and destination are not of same type. src type: %s, dest type: %s", src.Type().Name(), dest.Type().Name())
-	}
-}
-
-func setBoolValue(dest, src reflect.Value) error {
-	switch src.Kind() {
-	case reflect.String:
-		s := src.String()
-		if s == "false" { // lol
-			dest.Set(reflect.ValueOf(false))
-			return nil
-		}
-		dest.Set(reflect.ValueOf(true))
-		return nil
-	default:
-		return fmt.Errorf("dunno how to set a bool with that damned value")
-	}
+	return fmt.Errorf("src and destination are not of same type. src type: %s, dest type: %s", src.Type().Name(), dest.Type().Name())
 }
 
 // Fill takes the raw values from the moon document and assigns them to the
@@ -165,6 +144,8 @@ func (d *Doc) Fill(dest interface{}) error {
 	return nil
 }
 
+// NoValue is the error type returned when attempting to get a value from a
+// moon doc that isn't found.
 type NoValue struct {
 	fullpath string
 	relpath  string

lib/lex.go

@@ -41,6 +41,8 @@ func (t tokenType) String() string {
 		return "t_imaginary_number"
 	case t_variable:
 		return "t_variable"
+	case t_bool:
+		return "t_bool"
 	default:
 		panic(fmt.Sprintf("unknown token type: %v", t))
 	}
@@ -49,7 +51,8 @@ func (t tokenType) String() string {
 const (
 	t_error            tokenType = iota // a stored lex error
 	t_eof                               // end of file token
-	t_string                            // a string literal
+	t_string                            // a bare string
+	t_string_quoted                     // a quoted string
 	t_name                              // a name
 	t_comment                           // a comment
 	t_list_start                        // [
@@ -60,6 +63,7 @@ const (
 	t_real_number                       // a number
 	t_imaginary_number                  // an imaginary number
 	t_variable                          // e.g. @var_name, a variable name.
+	t_bool                              // a boolean token (true|false)
 )
 
 type stateFn func(*lexer) stateFn
@@ -143,6 +147,13 @@ func (l *lexer) emit(t tokenType) {
 		msg := fmt.Sprintf(`invalid name: "%s" (names cannot contain spaces)`, string(l.buf))
 		l.out <- token{t_error, msg}
 		return
+	case t_string:
+		switch string(l.buf) {
+		case "true", "false":
+			t = t_bool
+		}
+	case t_string_quoted:
+		t = t_string
 	}
 	l.out <- token{t, string(l.buf)}
 	l.buf = l.buf[0:0]
@@ -292,7 +303,7 @@ func lexQuotedString(delim rune) stateFn {
 	return func(l *lexer) stateFn {
 		switch r := l.next(); r {
 		case delim:
-			l.emit(t_string)
+			l.emit(t_string_quoted)
 			return lexRoot
 		case '\\':
 			switch r := l.next(); r {

lib/node.go

@@ -22,6 +22,7 @@ const (
 	n_list
 	n_object
 	n_variable
+	n_bool
 )
 
 var indent = "  "
@@ -476,3 +477,34 @@ func (v *variableNode) eval(ctx *context) (interface{}, error) {
 	}
 	return value, nil
 }
+
+type boolNode bool
+
+func (b *boolNode) Type() nodeType {
+	return n_bool
+}
+
+func (b *boolNode) parse(p *parser) error {
+	t := p.next()
+	if t.t != t_bool {
+		return fmt.Errorf("unexpected %s token while parsing bool", t.t)
+	}
+	switch t.s {
+	case "true":
+		*b = true
+	case "false":
+	default:
+		return fmt.Errorf("illegal lexeme for bool token: %s", t.s)
+	}
+	return nil
+}
+
+func (b *boolNode) pretty(w io.Writer, prefix string) error {
+	fmt.Fprintf(w, "%sbool:\n", prefix)
+	fmt.Fprintf(w, "%s%t\n", prefix+indent, *b)
+	return nil
+}
+
+func (b *boolNode) eval(ctx *context) (interface{}, error) {
+	return bool(*b), nil
+}

lib/parse.go

@@ -153,6 +153,12 @@ func (p *parser) parseValue() (node, error) {
 				return nil, err
 			}
 			return n, nil
+		case t_bool:
+			n := new(boolNode)
+			if err := n.parse(p); err != nil {
+				return nil, err
+			}
+			return n, nil
 		default:
 			return nil, fmt.Errorf("parse error: unexpected %v token while looking for value", t.t)
 		}

lib/tests/lex/10.in

@@ -0,0 +1,4 @@
+true
+false
+"true"
+"false"

lib/tests/lex/10.out

@@ -0,0 +1,4 @@
+{t_bool true}
+{t_bool false}
+{t_string true}
+{t_string false}

lib/tests/parse/07.in

@@ -0,0 +1,4 @@
+b_t: true
+b_f: false
+s_t: "true"
+s_f: "false"

lib/tests/parse/07.out

@@ -0,0 +1,25 @@
+root:
+  assign:
+    name:
+      b_t
+    value:
+      bool:
+        true
+  assign:
+    name:
+      b_f
+    value:
+      bool:
+        false
+  assign:
+    name:
+      s_t
+    value:
+      string:
+        true
+  assign:
+    name:
+      s_f
+    value:
+      string:
+        false