Add CQL temporal support

FEATURES.md

@@ -80,8 +80,9 @@ It includes [*OGC API - Features*](http://docs.opengeospatial.org/is/17-069r3/17
   - `INTERSECTS`,`DISJOINT`,`CONTAINS`,`WITHIN`,`EQUALS`,`CROSSES`,`OVERLAPS`,`TOUCHES`
 - [x] distance predicate
   - `DWITHIN`
-- [ ] temporal literals
-- [ ] temporal predicates
+- [x] temporal literals
+  - `1999-01-01`, `2001-12-25T10:01:02`
+- [x] temporal predicates
 - [ ] functions
 
 ### Output formats

NEWS.md

@@ -17,7 +17,7 @@
 * Add the `groupby` query parameter, and ability to aggregate query features
 * Support OGC API query parameter `sortby` (`orderBy` is deprecated)
 * Add OGC API query parameters `crs` and `bbox-crs` (#98)
-* Add support for CQL filtering with `filter` and `filter-crs` query parameters (#101, #102, #103)
+* Add CQL filtering query parameters `filter` and `filter-crs`  (#101, #102, #103, #105)
 
 ### Performance Improvements
 

hugo/content/usage/cql.md

@@ -202,3 +202,27 @@ The `DWITHIN` predicate allows testing whether a geometry lies within a given di
 ```
 DWITHIN(geom, POINT(-100 49), 0.1)
 ```
+
+## Temporal filters
+
+Temporal filtering in CQL supports date-time literals and the ability to use
+them in conditions against temporal-valued properties
+(PostgreSQL [dates or timestamps](https://www.postgresql.org/docs/current/datatype-datetime.html)).
+
+Date-time literals specifiy a date, or a timestamp including a date and time (with optional seconds value):
+```
+2001-01-01
+2001-01-01T10:23
+2001-01-01T10:23:45
+```
+
+Temporal values can be compared using the conditional operators `<`,`<=`,`>`,`>=`,`=`,`<>`:
+
+```
+t > 2001-01-01T00:00 AND t <= 2002-12-31T11:59:59
+```
+
+They can also be used in the `BETWEEN` predicate:
+```
+t BETWEEN 2001-01-01 AND 2001-12-31
+```

internal/cql/CQLParser.g4

@@ -2,7 +2,7 @@
 # CQL2 Antlr grammar, with small modifications.
 # - Additions: ILIKE
 
-# Build: in this dir: antlr -Dlanguage=Go -package cql CQL.g4 CqlLexer.g4
+# Build: in this dir: antlr -Dlanguage=Go -package cql CQLParser.g4 CqlLexer.g4
 #
 # See examples:
 # https://portal.ogc.org/files/96288#cql-bnf
@@ -33,7 +33,7 @@ predicate : binaryComparisonPredicate
             | inPredicate
             | spatialPredicate
             | distancePredicate
-//            | temporalPredicate
+            | temporalPredicate
 //            | arrayPredicate
 //            | existencePredicate
             ;
@@ -50,8 +50,8 @@ binaryComparisonPredicate : scalarExpression ComparisonOperator scalarExpression
 likePredicate :  propertyName (NOT)? ( LIKE | ILIKE ) characterLiteral;
 
 betweenPredicate : propertyName (NOT)? BETWEEN
-                             scalarExpression AND scalarExpression ;
-//                             (scalarValue | temporalExpression) AND (scalarValue | temporalExpression);
+//                             scalarExpression AND scalarExpression ;
+                             (scalarExpression | temporalExpression) AND (scalarExpression | temporalExpression);
 
 isNullPredicate : propertyName IS (NOT)? NULL;
 
@@ -68,11 +68,11 @@ scalarExpression : scalarValue
                     ;
 
 scalarValue : propertyName
-                    | characterLiteral
-                    | numericLiteral
-                    | booleanLiteral
-//                    | function
-                    ;
+            | characterLiteral
+            | numericLiteral
+            | booleanLiteral
+//                   | function
+             ;
 
 propertyName: Identifier;
 characterLiteral: CharacterStringLiteral;
@@ -129,16 +129,17 @@ coordinate : NumericLiteral NumericLiteral;
 # A temporal predicate evaluates if two temporal expressions satisfy the
 # specified temporal operator.
 #============================================================================*/
-/*
-temporalPredicate : temporalExpression (TemporalOperator | ComparisonOperator) temporalExpression;
+
+temporalPredicate : temporalExpression ComparisonOperator temporalExpression;
+//temporalPredicate : temporalExpression (TemporalOperator | ComparisonOperator) temporalExpression;
 
 temporalExpression : propertyName
                    | temporalLiteral
                    //| function
                    ;
 
 temporalLiteral: TemporalLiteral;
-*/
+
 
 /*============================================================================
 # The IN predicate

internal/cql/CQLParser.tokens

@@ -64,9 +64,21 @@ Exponent=63
 SignedInteger=64
 UnsignedInteger=65
 Sign=66
-WS=67
-CharacterStringLiteral=68
-QuotedQuote=69
+TemporalLiteral=67
+Instant=68
+FullDate=69
+DateYear=70
+DateMonth=71
+DateDay=72
+UtcTime=73
+TimeZoneOffset=74
+TimeHour=75
+TimeMinute=76
+TimeSecond=77
+NOW=78
+WS=79
+CharacterStringLiteral=80
+QuotedQuote=81
 '<'=2
 '='=3
 '>'=4
@@ -90,4 +102,4 @@ QuotedQuote=69
 ';'=53
 '?'=54
 '|'=55
-'\'\''=69
+'\'\''=81

internal/cql/CqlLexer.g4

@@ -176,22 +176,22 @@ Sign : PLUS | MINUS;
 # Definition of TEMPORAL literals
 #============================================================================*/
 
-/*
-TemporalLiteral : Instant | Interval;
+TemporalLiteral : Instant
+    // | Interval
+    ;
 Instant : FullDate | FullDate 'T' UtcTime | NOW LEFTPAREN RIGHTPAREN;
-Interval : (InstantInInterval)? SOLIDUS (InstantInInterval)?;
-InstantInInterval : '..' | Instant;
+//Interval : (InstantInInterval)? SOLIDUS (InstantInInterval)?;
+//InstantInInterval : '..' | Instant;
 FullDate : DateYear '-' DateMonth '-' DateDay;
 DateYear : DIGIT DIGIT DIGIT DIGIT;
 DateMonth : DIGIT DIGIT;
 DateDay : DIGIT DIGIT;
-UtcTime : TimeHour ':' TimeMinute ':' TimeSecond (TimeZoneOffset)?;
+UtcTime : TimeHour ':' TimeMinute  (':' TimeSecond)? (TimeZoneOffset)?;
 TimeZoneOffset : 'Z' | Sign TimeHour ':' TimeMinute;
 TimeHour : DIGIT DIGIT;
 TimeMinute : DIGIT DIGIT;
 TimeSecond : DIGIT DIGIT (PERIOD (DIGIT)+)?;
 NOW : N O W;
-*/
 
 /*============================================================================
 # ANTLR ignore whitespace

internal/cql/CqlLexer.tokens

@@ -64,9 +64,21 @@ Exponent=63
 SignedInteger=64
 UnsignedInteger=65
 Sign=66
-WS=67
-CharacterStringLiteral=68
-QuotedQuote=69
+TemporalLiteral=67
+Instant=68
+FullDate=69
+DateYear=70
+DateMonth=71
+DateDay=72
+UtcTime=73
+TimeZoneOffset=74
+TimeHour=75
+TimeMinute=76
+TimeSecond=77
+NOW=78
+WS=79
+CharacterStringLiteral=80
+QuotedQuote=81
 '<'=2
 '='=3
 '>'=4
@@ -90,4 +102,4 @@ QuotedQuote=69
 ';'=53
 '?'=54
 '|'=55
-'\'\''=69
+'\'\''=81

internal/cql/cql.go

@@ -261,6 +261,8 @@ func (l *cqlListener) ExitPredicate(ctx *PredicateContext) {
 		sql = sqlFor(ctx.SpatialPredicate())
 	} else if ctx.DistancePredicate() != nil {
 		sql = sqlFor(ctx.DistancePredicate())
+	} else if ctx.TemporalPredicate() != nil {
+		sql = sqlFor(ctx.TemporalPredicate())
 	}
 	ctx.SetSql(sql)
 }
@@ -323,8 +325,20 @@ func (l *cqlListener) ExitBetweenPredicate(ctx *BetweenPredicateContext) {
 	if ctx.NOT() != nil {
 		not = " NOT"
 	}
-	expr1 := sqlFor(ctx.ScalarExpression(0))
-	expr2 := sqlFor(ctx.ScalarExpression(1))
+	var expr1 string
+	if ctx.ScalarExpression(0) != nil {
+		expr1 = sqlFor(ctx.ScalarExpression(0))
+	}
+	if ctx.TemporalExpression(0) != nil {
+		expr1 = sqlFor(ctx.TemporalExpression(0))
+	}
+	var expr2 string
+	if ctx.ScalarExpression(0) != nil {
+		expr2 = sqlFor(ctx.ScalarExpression(1))
+	}
+	if ctx.TemporalExpression(0) != nil {
+		expr2 = sqlFor(ctx.TemporalExpression(1))
+	}
 	sql := " " + prop + not + " BETWEEN " + expr1 + " AND " + expr2
 	ctx.SetSql(sql)
 }
@@ -400,6 +414,35 @@ func (l *cqlListener) ExitDistancePredicate(ctx *DistancePredicateContext) {
 	ctx.SetSql(sb.String())
 }
 
+func (l *cqlListener) ExitTemporalPredicate(ctx *TemporalPredicateContext) {
+	expr1 := sqlFor(ctx.TemporalExpression(0))
+	expr2 := sqlFor(ctx.TemporalExpression(1))
+	op := getNodeText(ctx.ComparisonOperator())
+	sql := expr1 + " " + op + " " + expr2
+	ctx.SetSql(sql)
+}
+
+func (l *cqlListener) ExitTemporalExpression(ctx *TemporalExpressionContext) {
+	var sb strings.Builder
+	if ctx.PropertyName() != nil {
+		sb.WriteString(quotedName(getText(ctx.PropertyName())))
+	} else {
+		sb.WriteString(sqlFor(ctx.TemporalLiteral()))
+	}
+	ctx.SetSql(sb.String())
+}
+
+func (l *cqlListener) ExitTemporalLiteral(ctx *TemporalLiteralContext) {
+	val := strings.ToUpper(ctx.GetText())
+	//var sql string
+	if strings.HasPrefix(val, "NOW") {
+		val = "NOW"
+	}
+	sql := fmt.Sprintf("timestamp '%s'", val)
+	//TODO: handle NOW()
+	ctx.SetSql(sql)
+}
+
 func (l *cqlListener) ExitGeomExpression(ctx *GeomExpressionContext) {
 	var sb strings.Builder
 	if ctx.PropertyName() != nil {