move files

backend/v3/storage/database/operators.go

@@ -0,0 +1,139 @@
+package database
+
+import (
+	"time"
+
+	"golang.org/x/exp/constraints"
+)
+
+type Value interface {
+	Boolean | Number | Text | Instruction
+}
+
+type Operation interface {
+	BooleanOperation | NumberOperation | TextOperation
+}
+
+type Text interface {
+	~string | ~[]byte
+}
+
+type TextOperation uint8
+
+const (
+	// TextOperationEqual compares two strings for equality.
+	TextOperationEqual TextOperation = iota + 1
+	// TextOperationEqualIgnoreCase compares two strings for equality, ignoring case.
+	TextOperationEqualIgnoreCase
+	// TextOperationNotEqual compares two strings for inequality.
+	TextOperationNotEqual
+	// TextOperationNotEqualIgnoreCase compares two strings for inequality, ignoring case.
+	TextOperationNotEqualIgnoreCase
+	// TextOperationStartsWith checks if the first string starts with the second.
+	TextOperationStartsWith
+	// TextOperationStartsWithIgnoreCase checks if the first string starts with the second, ignoring case.
+	TextOperationStartsWithIgnoreCase
+)
+
+var textOperations = map[TextOperation]string{
+	TextOperationEqual:                " = ",
+	TextOperationEqualIgnoreCase:      " LIKE ",
+	TextOperationNotEqual:             " <> ",
+	TextOperationNotEqualIgnoreCase:   " NOT LIKE ",
+	TextOperationStartsWith:           " LIKE ",
+	TextOperationStartsWithIgnoreCase: " LIKE ",
+}
+
+func writeTextOperation[T Text](builder *StatementBuilder, col Column, op TextOperation, value T) {
+	switch op {
+	case TextOperationEqual, TextOperationNotEqual:
+		col.Write(builder)
+		builder.WriteString(textOperations[op])
+		builder.WriteString(builder.AppendArg(value))
+	case TextOperationEqualIgnoreCase, TextOperationNotEqualIgnoreCase:
+		if ignoreCaseCol, ok := col.(ignoreCaseColumn); ok {
+			ignoreCaseCol.WriteIgnoreCase(builder)
+		} else {
+			builder.WriteString("LOWER(")
+			col.Write(builder)
+			builder.WriteString(")")
+		}
+		builder.WriteString(textOperations[op])
+		builder.WriteString("LOWER(")
+		builder.WriteString(builder.AppendArg(value))
+		builder.WriteString(")")
+	case TextOperationStartsWith:
+		col.Write(builder)
+		builder.WriteString(textOperations[op])
+		builder.WriteString(builder.AppendArg(value))
+		builder.WriteString(" || '%'")
+	case TextOperationStartsWithIgnoreCase:
+		if ignoreCaseCol, ok := col.(ignoreCaseColumn); ok {
+			ignoreCaseCol.WriteIgnoreCase(builder)
+		} else {
+			builder.WriteString("LOWER(")
+			col.Write(builder)
+			builder.WriteString(")")
+		}
+		builder.WriteString(textOperations[op])
+		builder.WriteString("LOWER(")
+		builder.WriteString(builder.AppendArg(value))
+		builder.WriteString(")")
+		builder.WriteString(" || '%'")
+	default:
+		panic("unsupported text operation")
+	}
+}
+
+type Number interface {
+	constraints.Integer | constraints.Float | constraints.Complex | time.Time | time.Duration
+}
+
+type NumberOperation uint8
+
+const (
+	// NumberOperationEqual compares two numbers for equality.
+	NumberOperationEqual NumberOperation = iota + 1
+	// NumberOperationNotEqual compares two numbers for inequality.
+	NumberOperationNotEqual
+	// NumberOperationLessThan compares two numbers to check if the first is less than the second.
+	NumberOperationLessThan
+	// NumberOperationLessThanOrEqual compares two numbers to check if the first is less than or equal to the second.
+	NumberOperationAtLeast
+	// NumberOperationGreaterThan compares two numbers to check if the first is greater than the second.
+	NumberOperationGreaterThan
+	// NumberOperationGreaterThanOrEqual compares two numbers to check if the first is greater than or equal to the second.
+	NumberOperationAtMost
+)
+
+var numberOperations = map[NumberOperation]string{
+	NumberOperationEqual:       " = ",
+	NumberOperationNotEqual:    " <> ",
+	NumberOperationLessThan:    " < ",
+	NumberOperationAtLeast:     " <= ",
+	NumberOperationGreaterThan: " > ",
+	NumberOperationAtMost:      " >= ",
+}
+
+func writeNumberOperation[T Number](builder *StatementBuilder, col Column, op NumberOperation, value T) {
+	col.Write(builder)
+	builder.WriteString(numberOperations[op])
+	builder.WriteString(builder.AppendArg(value))
+}
+
+type Boolean interface {
+	~bool
+}
+
+type BooleanOperation uint8
+
+const (
+	BooleanOperationIsTrue BooleanOperation = iota + 1
+	BooleanOperationIsFalse
+)
+
+func writeBooleanOperation[T Boolean](builder *StatementBuilder, col Column, value T) {
+	col.Write(builder)
+	builder.WriteString(" IS ")
+	builder.WriteString(builder.AppendArg(value))
+}