From 7a537da9f4ded461ebadfdb71950e255cc8d139c Mon Sep 17 00:00:00 2001
From: shellyln <shellyln@users.noreply.github.com>
Date: Fri, 11 Feb 2022 23:21:19 +0900
Subject: [PATCH] Add date and datetime string parser.

---
 extra/classes/classes.go |  2 +
 extra/extra.go           | 94 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 96 insertions(+)

diff --git a/extra/classes/classes.go b/extra/classes/classes.go
index 23f88bb..b944568 100644
--- a/extra/classes/classes.go
+++ b/extra/classes/classes.go
@@ -7,4 +7,6 @@ const (
 	IntegerNumberStr = ":extra:IntegerNumberStr"
 	FloatNumberStr   = ":extra:FloatNumberStr"
 	NumericStr       = ":extra:NumericStr"
+	DateStr          = ":extra:DateStr"
+	DateTimeStr      = ":extra:DateTimeStr"
 )
diff --git a/extra/extra.go b/extra/extra.go
index 07fc99a..ec80822 100644
--- a/extra/extra.go
+++ b/extra/extra.go
@@ -174,3 +174,97 @@ func NumericStr() ParserFn {
 		ChangeClassName(clsz.NumericStr),
 	)
 }
+
+// Parse the ISO 8601 date string. (yyyy-MM-dd)
+func DateStr() ParserFn {
+	return Trans(
+		FlatGroup(
+			ZeroOrOnce(Seq("-")),
+			Repeat(Times{Min: 4, Max: -1}, Number()),
+			Seq("-"),
+			CharRange(RuneRange{Start: '0', End: '1'}),
+			CharRange(RuneRange{Start: '0', End: '9'}),
+			Seq("-"),
+			CharRange(RuneRange{Start: '0', End: '3'}),
+			CharRange(RuneRange{Start: '0', End: '9'}),
+		),
+		Concat,
+		ChangeClassName(clsz.DateStr),
+	)
+}
+
+// Parse the ISO 8601 datetime string.
+// (yyyy-MM-ddThh:mmZ , ... , yyyy-MM-ddThh:mm:ss.fffffffffZ)
+// (yyyy-MM-ddThh:mm+00:00 , ... , yyyy-MM-ddThh:mm:ss.fffffffff+00:00)
+func DateTimeStr() ParserFn {
+	return Trans(
+		FlatGroup(
+			ZeroOrOnce(Seq("-")),
+			Repeat(Times{Min: 4, Max: -1}, Number()),
+			Seq("-"),
+			CharRange(RuneRange{Start: '0', End: '1'}),
+			CharRange(RuneRange{Start: '0', End: '9'}),
+			Seq("-"),
+			CharRange(RuneRange{Start: '0', End: '3'}),
+			CharRange(RuneRange{Start: '0', End: '9'}),
+			Seq("T"),
+			CharRange(RuneRange{Start: '0', End: '2'}),
+			CharRange(RuneRange{Start: '0', End: '9'}),
+			Seq(":"),
+			CharRange(RuneRange{Start: '0', End: '5'}),
+			CharRange(RuneRange{Start: '0', End: '9'}),
+			First(
+				FlatGroup(
+					Seq(":"),
+					CharRange(RuneRange{Start: '0', End: '6'}),
+					CharRange(RuneRange{Start: '0', End: '9'}),
+					First(
+						FlatGroup(
+							Seq("."),
+							Trans(
+								Repeat(Times{Min: 1, Max: 9}, // 3: milli, 6: micro, 9: nano
+									CharRange(RuneRange{Start: '0', End: '9'}),
+								),
+								Concat,
+								func(ctx ParserContext, asts AstSlice) (AstSlice, error) {
+									return AstSlice{{
+										Type:  AstType_String,
+										Value: (asts[len(asts)-1].Value.(string) + "000000000")[0:9],
+									}}, nil
+								},
+							),
+						),
+						Zero(Ast{
+							Type:  AstType_String,
+							Value: ".000000000",
+						}),
+					),
+				),
+				Zero(Ast{
+					Type:  AstType_String,
+					Value: ":00.000000000",
+				}),
+			),
+			First(
+				FlatGroup(
+					erase(Seq("Z")),
+					Zero(Ast{
+						Type:  AstType_String,
+						Value: "+00:00",
+					}),
+				),
+				FlatGroup(
+					CharClass("+", "-"),
+					Repeat(Times{Min: 2, Max: 2},
+						CharRange(RuneRange{Start: '0', End: '9'}),
+					),
+					Seq(":"),
+					CharRange(RuneRange{Start: '0', End: '5'}),
+					CharRange(RuneRange{Start: '0', End: '9'}),
+				),
+			),
+		),
+		Concat,
+		ChangeClassName(clsz.DateTimeStr),
+	)
+}