From 5d73aea0169c691b4c96d85353b1dccc5c1199e2 Mon Sep 17 00:00:00 2001
From: Silvan Jegen <s.jegen@gmail.com>
Date: Sun, 25 Dec 2016 19:29:55 +0100
Subject: Start writing the parser

---
 conf/parser.go | 49 ++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 42 insertions(+), 7 deletions(-)

(limited to 'conf/parser.go')

diff --git a/conf/parser.go b/conf/parser.go
index 85d9b11..75f610c 100644
--- a/conf/parser.go
+++ b/conf/parser.go
@@ -1,3 +1,14 @@
+// grammar of the config file
+//
+// config = module module module
+// module = name object
+// name = 'input' | 'filter' | 'etc.'
+// object = '{' keyvalue | keyvalue | ... '}'
+// keyvalue = statement '=>' value
+// statement = name | if
+// value = literal | '[' literal ']'
+// literal = '"' name '"'
+
 package conf
 
 import (
@@ -12,17 +23,41 @@ type Config struct {
 }
 
 type parser struct {
-	scanner
+	s    scanner
+	last token
+	cur  token
+}
+
+func newParser(s *scanner) *parser {
+	p := &parser{
+		s: *s,
+	}
+
+	return p
 }
 
 func NewConfig(r io.Reader) *Config {
-	s := newScanner(r)
-	tok, err := s.Scan()
+	p := newParser(newScanner(r))
+	p.startparsing()
+
+	return &Config{}
+}
+
+func (p *parser) startparsing() {
+	var err error
+
+	p.last = p.cur
+	p.cur, err = p.s.Scan()
 	for err == nil {
-		fmt.Fprintf(os.Stderr, "tokentype: %d, token: %q offset: %d, line: %d\n", tok.Type, tok.Lit, tok.Offset, tok.LineNr)
-		tok, err = s.Scan()
+		fmt.Fprintf(os.Stderr, "tokentype: %d, token: %q offset: %d, line: %d\n", p.cur.Type, p.cur.Lit, p.cur.Offset, p.cur.LineNr)
+		p.last = p.cur
+		p.cur, err = p.s.Scan()
 	}
-	fmt.Fprintf(os.Stderr, "Error: tokentype: %d, token: %q, err: %v\n", tok.Type, tok.Lit, err)
+	fmt.Fprintf(os.Stderr, "Error: tokentype: %d, token: %q, err: %v\n", p.cur.Type, p.cur.Lit, err)
+}
 
-	return &Config{}
+func (p *parser) module(name string) {
+}
+
+func (p *parser) object() {
 }
-- 
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