Add crossref resolution, minor api changes, first template inspired by plain.bst

1 files changed, 37 insertions, 12 deletions

diff --git a/parser.go b/parser.go
index b4a3ada..15e941d 100644
--- a/parser.go
+++ b/parser.go
@@ -48,11 +48,12 @@ func NewParser(r io.Reader) *parser {
 	default:
 		name = ""
 	}
-	res := make(map[string]Value)
+	res := make(map[string]Value, len(strings))
 	for key, s := range strings {
-		res[key] = []Literal{StringLiteral(s)}
+		res[key] = StringLiteral(s)
 	}
-	db := &Database{Strings: res, Entries: make(map[string]Entry)}
+	db := &Database{Strings: res, Entries: make(map[string]Entry),
+		CrossRefs: make(map[string]int)}
 	return &parser{Reader: bufio.NewReader(r), lineno: 1, colno: 0,
 		fname: name, Database: db}
 }
@@ -229,7 +230,7 @@ func (p *parser) readNumber() NumberLiteral {
 	return NumberLiteral(n)
 }
 
-func (p *parser) readLiteral() Literal {
+func (p *parser) readLiteral() Value {
 	if ch := p.peek(); ch == '{' {
 		return p.readBraceLiteral()
 	} else if ch == '"' {
@@ -242,16 +243,18 @@ func (p *parser) readLiteral() Literal {
 			panic(p.NewError("Expected an identifier"))
 		}
 		if v, in := p.Strings[id]; in {
-			return VariableLiteral{id, &v}
+			return VarLiteral{id, &v}
 		} else {
 			p.Warning(fmt.Sprintf("Unknown string %q", id))
-			return VariableLiteral{id, &v}
+			l := Value(StringLiteral(""))
+			return VarLiteral{id, &l}
 		}
 	}
 }
 
-func (p *parser) readValue() (res Value) {
+func (p *parser) readValue() Value {
 	var ch rune
+	var res LiteralList
 	res = append(res, p.readLiteral())
 	for {
 		p.eatSpace()
@@ -263,7 +266,11 @@ func (p *parser) readValue() (res Value) {
 			break
 		}
 	}
-	return
+	if len(res) == 1 {
+		return res[0]
+	} else {
+		return res
+	}
 }
 
 func (p *parser) readIdValue() (string, Value) {
@@ -297,7 +304,8 @@ func (p *parser) readOpen() rune {
 func (p *parser) readPreamble() {
 	close := p.readOpen()
 	p.eatSpace()
-	p.Preamble = append(p.Preamble, p.readValue())
+	prb := p.Preamble.(LiteralList)
+	p.Preamble = append(prb, p.readValue())
 	p.eatSpace()
 	if ch := p.read(); ch != close {
 		p.unread()
@@ -323,6 +331,18 @@ func (p *parser) readString() {
 	}
 }
 
+func (p *parser) checkCrossRef(id string, value Value) {
+	if id != "crossref" {
+		return
+	}
+	key := strings.ToLower(value.String())
+	if _, in := p.Entries[key]; in {
+		p.Warning(fmt.Sprintf("Crossreference %q defined before being used",
+			key))
+	}
+	p.CrossRefs[key] += 1
+}
+
 func (p *parser) readEntry(t string) {
 	close := p.readOpen()
 	p.eatSpace()
@@ -332,10 +352,11 @@ func (p *parser) readEntry(t string) {
 	entry.Type = t
 	entry.Fields = make(map[string]Value)
 	key = strings.ToLower(key)
+	store := true
 
 	if _, in := p.Entries[key]; in {
 		p.Warning(fmt.Sprintf("Entry %q already defined, ignoring", key))
-		return
+		store = false
 	}
 
 	for {
@@ -354,6 +375,7 @@ func (p *parser) readEntry(t string) {
 					p.Warning(fmt.Sprintf("Field %q already defined, ignoring",
 						id))
 				} else {
+					p.checkCrossRef(id, value)
 					entry.Fields[id] = value
 					entry.FNames = append(entry.FNames, id)
 				}
@@ -363,8 +385,11 @@ func (p *parser) readEntry(t string) {
 			panic(p.NewError(fmt.Sprintf("Expected ',' or %q", close)))
 		}
 	}
-	p.Entries[key] = entry
-	p.EKeys = append(p.EKeys, key)
+
+	if store {
+		p.Entries[key] = entry
+		p.EKeys = append(p.EKeys, key)
+	}
 }
 
 func (p *parser) readDeclaration() (err error) {