add file trace to parser, refactor, fix inner type

core/parser.go

@@ -17,6 +17,7 @@ type ParsingError struct {
 	Description string
 	Causer      *Token
 	Source      string
+	Trace       []string
 }
 
 func (p ParsingError) Error() string {
@@ -26,7 +27,7 @@ func (p ParsingError) Error() string {
 // Format Print a rich and informative error
 func (p ParsingError) Format() string {
 	src := []rune(p.Source)
-	builder := strings.Builder{}
+	b := strings.Builder{}
 
 	lineNumber := 1
 	lineBeginning := 0
@@ -46,39 +47,46 @@ func (p ParsingError) Format() string {
 	}
 
 	descriptor := fmt.Sprintf("%d:%d", lineNumber, int(p.Causer.Start)-lineBeginning+1)
-	builder.WriteString(p.Description)
-	builder.WriteRune('\n')
+	b.WriteString(p.Description)
+	b.WriteRune('\n')
 
-	builder.WriteString(descriptor)
-	builder.WriteString(" | ")
-	builder.WriteString(string(src[lineBeginning:lineEnd]))
+	b.WriteString(descriptor)
+	b.WriteString(" | ")
+	b.WriteString(string(src[lineBeginning:lineEnd]))
 
-	builder.WriteString("\n")
-	builder.WriteString(strings.Repeat(" ", len(descriptor)))
-	builder.WriteString("  ")
+	b.WriteString("\n")
+	b.WriteString(strings.Repeat(" ", len(descriptor)))
+	b.WriteString("  ")
 	for i := lineBeginning; i <= int(p.Causer.Start); i++ {
-		builder.WriteRune(' ')
+		b.WriteRune(' ')
 	}
 
 	for i := 0; i < int(p.Causer.Length); i++ {
-		builder.WriteRune('^')
+		b.WriteRune('^')
 	}
-	builder.WriteRune('\n')
+	b.WriteRune('\n')
+	b.WriteRune('\n')
 
-	return builder.String()
+	for i := len(p.Trace) - 1; i >= 0; i-- {
+		b.WriteString(fmt.Sprintf("[%d] %s\n", i, p.Trace[i]))
+	}
+
+	return b.String()
 }
 
 type Parser struct {
 	source string
+	trace  []string
 	tokens []Token
 	prev   *Token
 	curr   *Token
 	pos    Pos
 }
 
-func NewParser(source string, tokens []Token) *Parser {
+func NewParser(source string, trace []string, tokens []Token) *Parser {
 	return &Parser{
 		source: source,
+		trace:  trace,
 		tokens: tokens,
 		pos:    0,
 	}
@@ -121,6 +129,7 @@ func (p *Parser) Parse(path string) (*Program, error) {
 			}
 
 			imports = append(imports, p.prev.Lexeme[1:len(p.prev.Lexeme)-1])
+			continue
 		}
 
 		b, err := p.block(true)
@@ -190,6 +199,7 @@ func (p *Parser) error(error string, causer *Token) error {
 		Description: error,
 		Causer:      causer,
 		Source:      p.source,
+		Trace:       p.trace,
 	}
 }