Remove unused PreprocPattern, allow sensible defaults with aws setup, and add a little more documentation

3 files changed, 12 insertions, 4 deletions

diff --git a/aws.go b/aws.go
index 70189ea..59f1a7e 100644
--- a/aws.go
+++ b/aws.go
@@ -20,7 +20,7 @@ import (
 	"github.com/aws/aws-sdk-go/service/sqs"
 )
 
-const PreprocPattern = `_bin[0-9].[0-9].png`
+const defaultAwsRegion = `eu-west-2`
 
 type Qmsg struct {
 	Id, Handle, Body string
@@ -35,8 +35,11 @@ type ObjMeta struct {
 	Date time.Time
 }
 
+// AwsConn contains the necessary things to interact with various AWS
+// services in ways useful for the bookpipeline package. It is
+// designed to be generic enough to swap in other backends easily.
 type AwsConn struct {
-	// these need to be set before running Init()
+	// these should be set before running Init(), or left to defaults
 	Region string
 	Logger *log.Logger
 
@@ -53,10 +56,10 @@ type AwsConn struct {
 // MinimalInit does the bare minimum to initialise aws services
 func (a *AwsConn) MinimalInit() error {
 	if a.Region == "" {
-		return errors.New("No Region set")
+		a.Region = defaultAwsRegion
 	}
 	if a.Logger == nil {
-		return errors.New("No logger set")
+		a.Logger = log.New(os.Stdout, "", 0)
 	}
 
 	var err error
diff --git a/graph.go b/graph.go
index 8d6c857..a7b46bc 100644
--- a/graph.go
+++ b/graph.go
@@ -32,6 +32,8 @@ type GraphConf struct {
 	Pgnum, Conf float64
 }
 
+// createLine creates a horizontal line with a particular y value for
+// a graph
 func createLine(xvalues []float64, y float64, c drawing.Color) chart.ContinuousSeries {
 	var yvalues []float64
 	for range xvalues {
@@ -46,10 +48,12 @@ func createLine(xvalues []float64, y float64, c drawing.Color) chart.ContinuousS
 	}
 }
 
+// Graph creates a graph of the confidence of each page in a book
 func Graph(confs map[string]*Conf, bookname string, w io.Writer) error {
 	return GraphOpts(confs, bookname, "Page number", true, w)
 }
 
+// Graph creates a graph of confidences
 func GraphOpts(confs map[string]*Conf, bookname string, xaxis string, guidelines bool, w io.Writer) error {
 	if len(confs) < 2 {
 		return errors.New("Not enough valid confidences")
diff --git a/pdf.go b/pdf.go
index a03aecc..f8217ba 100644
--- a/pdf.go
+++ b/pdf.go
@@ -31,6 +31,7 @@ func pxToPt(i int) float64 {
 	return float64(i) / pageWidth
 }
 
+// Fpdf abstracts the gofpdf.Fpdf adding some useful methods
 type Fpdf struct {
 	fpdf *gofpdf.Fpdf
 }