Generate code for parser

G2 code generation used after benchmarking.

style	benchmark           old ns/op     new ns/op     delta
T0		BenchmarkParser     672           5631          +737.95%
T1		BenchmarkParser     672           5579          +730.21%
G0		BenchmarkParser     672           4049          +502.53%
G1		BenchmarkParser     672           3868          +475.60%
G2		BenchmarkParser     672           3543          +427.23%

F0 and F1 create massive Go source (6.0M) and so were not tested.

Invalid tests removed, additional tests for invalid input to be added
later.

nquads/nquads.go

@@ -19,7 +19,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"strings"
 
 	"github.com/google/cayley/graph"
 )
@@ -32,143 +31,11 @@ var (
 )
 
 func Parse(str string) (*graph.Triple, error) {
-	// Skip leading whitespace.
-	str = trimSpace(str)
-	// Check for a comment
-	if str != "" && str[0] == '#' {
-		return nil, nil
+	t, err := parse([]rune(str))
+	if err != nil {
+		return nil, err
 	}
-	sub, remainder := getTripleComponent(str)
-	if sub == "" {
-		return nil, ErrAbsentSubject
-	}
-	str = trimSpace(remainder)
-	pred, remainder := getTripleComponent(str)
-	if pred == "" {
-		return nil, ErrAbsentPredicate
-	}
-	str = trimSpace(remainder)
-	obj, remainder := getTripleComponent(str)
-	if obj == "" {
-		return nil, ErrAbsentObject
-	}
-	str = trimSpace(remainder)
-	prov, remainder := getTripleComponent(str)
-	str = trimSpace(remainder)
-	if str != "" && str[0] == '.' {
-		return &graph.Triple{sub, pred, obj, prov}, nil
-	}
-	return nil, ErrUnterminated
-}
-
-func isSpace(s uint8) bool {
-	return s == ' ' || s == '\t' || s == '\r'
-}
-
-func trimSpace(str string) string {
-	i := 0
-	for i < len(str) && isSpace(str[i]) {
-		i += 1
-	}
-	return str[i:]
-}
-
-func getTripleComponent(str string) (head, tail string) {
-	if len(str) == 0 {
-		return "", str
-	}
-	if str[0] == '<' {
-		return getUriPart(str[1:])
-	} else if str[0] == '"' {
-		return getQuotedPart(str[1:])
-	} else if str[0] == '.' {
-		return "", str
-	} else {
-		// Technically not part of the spec. But we do it anyway for convenience.
-		return getUnquotedPart(str)
-	}
-}
-
-func getUriPart(str string) (head, tail string) {
-	i := 0
-	for i < len(str) && str[i] != '>' {
-		i += 1
-	}
-	if i == len(str) {
-		return "", str
-	}
-	head = str[0:i]
-	return head, str[i+1:]
-}
-
-func getQuotedPart(str string) (head, tail string) {
-	var (
-		i     int
-		start int
-	)
-	for i < len(str) && str[i] != '"' {
-		if str[i] == '\\' {
-			head += str[start:i]
-			switch str[i+1] {
-			case '\\':
-				head += "\\"
-			case 'r':
-				head += "\r"
-			case 'n':
-				head += "\n"
-			case 't':
-				head += "\t"
-			case '"':
-				head += "\""
-			default:
-				return "", str
-			}
-			i += 2
-			start = i
-			continue
-		}
-		i += 1
-	}
-	if i == len(str) {
-		return "", str
-	}
-	head += str[start:i]
-	i += 1
-	switch {
-	case strings.HasPrefix(str[i:], "^^<"):
-		// Ignore type, for now
-		_, tail = getUriPart(str[i+3:])
-	case str[i] == '@':
-		_, tail = getUnquotedPart(str[i+1:])
-	default:
-		tail = str[i:]
-	}
-
-	return head, tail
-}
-
-func getUnquotedPart(str string) (head, tail string) {
-	var (
-		i       int
-		initStr = str
-		start   int
-	)
-	for i < len(str) && !isSpace(str[i]) {
-		if str[i] == '"' {
-			part, remainder := getQuotedPart(str[i+1:])
-			if part == "" {
-				return part, initStr
-			}
-			head += str[start:i]
-			str = remainder
-			i = 0
-			start = 0
-			head += part
-		}
-		i += 1
-	}
-	head += str[start:i]
-	return head, str[i:]
+	return &t, nil
 }
 
 type Decoder struct {