Fixed panic when parsing commands, the lexer is a bit too permissive, c…

…loses #78 Now: ``` ⧐ $1 parser errors: Illegal token '$1' no prefix parse function for ILLEGAL found ``
abs-lang · Dec 28, 2018 · 5e7d003 · 5e7d003
1 parent 1080673
commit 5e7d003
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Showing 3 changed files with 17 additions and 5 deletions.
diff --git a/lexer/lexer.go b/lexer/lexer.go
@@ -74,7 +74,7 @@ func (l *Lexer) NextToken() token.Token {
 	case '/':
 		if l.peekChar() == '/' {
 			tok.Type = token.COMMENT
-			tok.Literal = l.readComment()
+			tok.Literal = l.readLine()
 		} else if l.peekChar() == '=' {
 			tok.Type = token.COMP_SLASH
 			tok.Literal = "/="
@@ -84,7 +84,7 @@ func (l *Lexer) NextToken() token.Token {
 		}
 	case '#':
 		tok.Type = token.COMMENT
-		tok.Literal = l.readComment()
+		tok.Literal = l.readLine()
 	case '&':
 		if l.peekChar() == '&' {
 			tok.Type = token.AND
@@ -178,8 +178,13 @@ func (l *Lexer) NextToken() token.Token {
 		tok.Type = token.STRING
 		tok.Literal = l.readString()
 	case '$':
-		tok.Type = token.COMMAND
-		tok.Literal = l.readCommand()
+		if l.peekChar() == '(' {
+			tok.Type = token.COMMAND
+			tok.Literal = l.readCommand()
+		} else {
+			tok.Type = token.ILLEGAL
+			tok.Literal = l.readLine()
+		}
 	case '[':
 		tok = newToken(token.LBRACKET, l.ch)
 	case ']':
@@ -331,7 +336,7 @@ func (l *Lexer) readString() string {
 // Go ahead until you find a new line.
 // This makes it so that comments take
 // a full line.
-func (l *Lexer) readComment() string {
+func (l *Lexer) readLine() string {
 	position := l.position
 	for {
 		l.readChar()

diff --git a/lexer/lexer_test.go b/lexer/lexer_test.go
@@ -71,6 +71,7 @@ one | two | tree
 null
 nullo
 &^>><<
+$111
 `
 
 	tests := []struct {
@@ -265,6 +266,7 @@ nullo
 		{token.BIT_XOR, "^"},
 		{token.BIT_RSHIFT, ">>"},
 		{token.BIT_LSHIFT, "<<"},
+		{token.ILLEGAL, "$111"},
 		{token.EOF, ""},
 	}
 

diff --git a/parser/parser.go b/parser/parser.go
@@ -146,6 +146,11 @@ func New(l *lexer.Lexer) *Parser {
 func (p *Parser) nextToken() {
 	p.curToken = p.peekToken
 	p.peekToken = p.l.NextToken()
+
+	if p.curTokenIs(token.ILLEGAL) {
+		msg := fmt.Sprintf(`Illegal token '%s'`, p.curToken.Literal)
+		p.errors = append(p.errors, msg)
+	}
 }
 
 func (p *Parser) curTokenIs(t token.TokenType) bool {