Merge pull request #43 from shellcromancer/main

feat: add kusto scalar functions: now(), toupper(), tolower()

.gitignore

@@ -0,0 +1,2 @@
+# binaries in cmd/
+pql

README.md

@@ -82,12 +82,16 @@ list will be passed through to the underlying SQL engine. This allows the usage
 of the full APIs implemented by the underlying engine.
 
 - [`not`](https://learn.microsoft.com/en-us/azure/data-explorer/kusto/query/not-function)
+- [`now`](https://learn.microsoft.com/en-us/azure/data-explorer/kusto/query/now-function)
 - [`isnull`](https://learn.microsoft.com/en-us/azure/data-explorer/kusto/query/isnull-function)
   and [`isnotnull`](https://learn.microsoft.com/en-us/azure/data-explorer/kusto/query/isnotnull-function)
 - [`strcat`](https://learn.microsoft.com/en-us/azure/data-explorer/kusto/query/strcat-function)
 - [`iff`/`iif`](https://learn.microsoft.com/en-us/azure/data-explorer/kusto/query/iff-function)
 - [`count`](https://learn.microsoft.com/en-us/azure/data-explorer/kusto/query/count-aggregation-function)
 - [`countif`](https://learn.microsoft.com/en-us/azure/data-explorer/kusto/query/countif-aggregation-function)
+- [`tolower`](https://learn.microsoft.com/en-us/azure/data-explorer/kusto/query/tolower-function)
+- [`toupper`](https://learn.microsoft.com/en-us/azure/data-explorer/kusto/query/toupper-function)
+
 
 Column names with special characters can be escaped with backticks.
 

pql.go

@@ -711,14 +711,17 @@ var knownFunctions struct {
 func initKnownFunctions() map[string]*functionRewrite {
 	knownFunctions.init.Do(func() {
 		knownFunctions.m = map[string]*functionRewrite{
-			"not":       {write: writeNotFunction},
-			"isnull":    {write: writeIsNullFunction, needsParens: true},
-			"isnotnull": {write: writeIsNotNullFunction, needsParens: true},
-			"strcat":    {write: writeStrcatFunction, needsParens: true},
 			"count":     {write: writeCountFunction},
 			"countif":   {write: writeCountIfFunction},
-			"iff":       {write: writeIfFunction, needsParens: true},
 			"iif":       {write: writeIfFunction, needsParens: true},
+			"iff":       {write: writeIfFunction, needsParens: true},
+			"isnotnull": {write: writeIsNotNullFunction, needsParens: true},
+			"isnull":    {write: writeIsNullFunction, needsParens: true},
+			"not":       {write: writeNotFunction},
+			"now":       {write: writeNowFunction},
+			"strcat":    {write: writeStrcatFunction, needsParens: true},
+			"tolower":   {write: writeToLowerFunction, needsParens: true},
+			"toupper":   {write: writeToUpperFunction, needsParens: true},
 		}
 	})
 	return knownFunctions.m
@@ -742,6 +745,21 @@ func writeNotFunction(ctx *exprContext, sb *strings.Builder, x *parser.CallExpr)
 	return nil
 }
 
+func writeNowFunction(ctx *exprContext, sb *strings.Builder, x *parser.CallExpr) error {
+	if len(x.Args) != 0 {
+		return &compileError{
+			source: ctx.source,
+			span: parser.Span{
+				Start: x.Lparen.End,
+				End:   x.Rparen.Start,
+			},
+			err: fmt.Errorf("now()) takes a no arguments (got %d)", len(x.Args)),
+		}
+	}
+	sb.WriteString("CURRENT_TIMESTAMP")
+	return nil
+}
+
 func writeIsNullFunction(ctx *exprContext, sb *strings.Builder, x *parser.CallExpr) error {
 	if len(x.Args) != 1 {
 		return &compileError{
@@ -862,6 +880,44 @@ func writeIfFunction(ctx *exprContext, sb *strings.Builder, x *parser.CallExpr)
 	return nil
 }
 
+func writeToLowerFunction(ctx *exprContext, sb *strings.Builder, x *parser.CallExpr) error {
+	if len(x.Args) != 1 {
+		return &compileError{
+			source: ctx.source,
+			span: parser.Span{
+				Start: x.Lparen.End,
+				End:   x.Rparen.Start,
+			},
+			err: fmt.Errorf("tolower(x) takes a single argument (got %d)", len(x.Args)),
+		}
+	}
+	sb.WriteString("LOWER(")
+	if err := writeExpression(ctx, sb, x.Args[0]); err != nil {
+		return err
+	}
+	sb.WriteString(")")
+	return nil
+}
+
+func writeToUpperFunction(ctx *exprContext, sb *strings.Builder, x *parser.CallExpr) error {
+	if len(x.Args) != 1 {
+		return &compileError{
+			source: ctx.source,
+			span: parser.Span{
+				Start: x.Lparen.End,
+				End:   x.Rparen.Start,
+			},
+			err: fmt.Errorf("toupper(x) takes a single argument (got %d)", len(x.Args)),
+		}
+	}
+	sb.WriteString("UPPER(")
+	if err := writeExpression(ctx, sb, x.Args[0]); err != nil {
+		return err
+	}
+	sb.WriteString(")")
+	return nil
+}
+
 func quoteSQLString(sb *strings.Builder, s string) {
 	sb.WriteString("'")
 	for _, b := range []byte(s) {

testdata/Goldens/ProjectNow/input.pql

@@ -0,0 +1,2 @@
+StormEvents
+| project now = now(), State

testdata/Goldens/ProjectNow/output.sql

@@ -0,0 +1 @@
+SELECT CURRENT_TIMESTAMP AS "now", "State" AS "State" FROM "StormEvents";

testdata/Goldens/WhereToLower/input.pql

@@ -0,0 +1,2 @@
+StormEvents
+| where tolower(EventType) == "tornado"

testdata/Goldens/WhereToLower/output.csv

@@ -0,0 +1,2 @@
+EventId,State,EventType,DamageProperty
+60913,FLORIDA,Tornado,6200000

testdata/Goldens/WhereToLower/output.sql

@@ -0,0 +1 @@
+SELECT * FROM "StormEvents" WHERE coalesce((LOWER("EventType")) = 'tornado', FALSE);

testdata/Goldens/WhereToUpper/input.pql

@@ -0,0 +1,2 @@
+StormEvents
+| where toupper(EventType) == "TORNADO"

testdata/Goldens/WhereToUpper/output.csv

@@ -0,0 +1,2 @@
+EventId,State,EventType,DamageProperty
+60913,FLORIDA,Tornado,6200000

testdata/Goldens/WhereToUpper/output.sql

@@ -0,0 +1 @@
+SELECT * FROM "StormEvents" WHERE coalesce((UPPER("EventType")) = 'TORNADO', FALSE);