From 726b5a377b49424835e50e61a6854050913ba2d9 Mon Sep 17 00:00:00 2001
From: Maurice Makaay <maurice@makaay.nl>
Date: Wed, 19 Jun 2019 11:28:03 +0000
Subject: [PATCH] A bit of code cleanup, to let the date/time code better
 represent the ideas behind the followed methodology.

---
 value_datetime.go | 48 ++++++++++++++++++++++++++++++++---------------
 1 file changed, 33 insertions(+), 15 deletions(-)

diff --git a/value_datetime.go b/value_datetime.go
index be2f186..25e7196 100644
--- a/value_datetime.go
+++ b/value_datetime.go
@@ -4,6 +4,7 @@ import (
 	"time"
 
 	"git.makaay.nl/mauricem/go-parsekit/parse"
+	"git.makaay.nl/mauricem/go-parsekit/tokenize"
 )
 
 var (
@@ -63,6 +64,8 @@ var (
 	tzTok  = tok.Str("Z07:00", tz)
 
 	// The full date/time parse format, based on the above definitions.
+	// The first token denotes the type of date/time value.
+	// The rest of the tokens contain layout fragments for time.Parse().
 	offsetDateTime = tok.Str(coffsetDateTime, c.Seq(dateTok, tdelimTok, timeTok, microTok, tzTok))
 	localDateTime  = tok.Str(clocalDateTime, c.Seq(dateTok, tdelimTok, timeTok, microTok))
 	localDate      = tok.Str(clocalDate, dateTok)
@@ -71,21 +74,36 @@ var (
 )
 
 func (t *parser) startDateTime(p *parse.API) {
-	if p.Accept(datetime) {
-		tokens := p.Result().Tokens()
-		valueType := tokens[0].Type.(cmdType)
-		layout := ""
-		for _, l := range tokens[1:] {
-			layout += l.Type.(string)
-		}
-		input := string(tokens[0].Runes)
-		value, err := time.Parse(layout, input)
-		if err == nil {
-			t.emitCommand(valueType, value)
-		} else {
-			p.Error("Cannot parse value 0%s: %s", input, err)
-		}
-	} else {
+	if !p.Accept(datetime) {
 		p.Expected("a date and/or time")
+		return
+	}
+	tokens := p.Result().Tokens()
+	valueType := getDateTimeValueType(&tokens)
+	input, value, err := getDateTimeValue(&tokens)
+	if err == nil {
+		t.emitCommand(valueType, value)
+	} else {
+		p.Error("Cannot parse value 0%s: %s", input, err)
 	}
 }
+
+// The first token is a token that wraps the complete date/time input.
+// Its type denotes the type of date/time value that it wraps.
+func getDateTimeValueType(tokens *[]*tokenize.Token) cmdType {
+	return (*tokens)[0].Type.(cmdType)
+}
+
+// The rest of the tokens contain fragments that can be used with
+// time.Parse() to parse the provided date/time input. Here, these fragments
+// are combined into a layout string, which is then used to parse
+// the input string.
+func getDateTimeValue(tokens *[]*tokenize.Token) (string, time.Time, error) {
+	layout := ""
+	for _, l := range (*tokens)[1:] {
+		layout += l.Type.(string)
+	}
+	input := string((*tokens)[0].Runes)
+	value, err := time.Parse(layout, input)
+	return input, value, err
+}