1 files changed, 93 insertions, 0 deletions
diff --git a/internal/mapr/setcondition.go b/internal/mapr/setcondition.go
new file mode 100644
index 0000000..8c5cfc9
--- /dev/null
+++ b/internal/mapr/setcondition.go
@@ -0,0 +1,93 @@
+package mapr
+
+import (
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/mimecast/dtail/internal/mapr/funcs"
+)
+
+// Represent a parsed "set" clause, used by mapr.Query
+type setCondition struct {
+	lString string
+
+	rType   fieldType
+	rString string
+	rFloat  float64
+
+	// For now only text functions are supported.
+	// Maybe in the future we can have typed functions too
+	// so that a float input/output is possible.
+	functionStack funcs.FunctionStack
+}
+
+func (sc *setCondition) String() string {
+	return fmt.Sprintf("setCondition(lString:%s,rString:%s,rType:%s,functionStack:%v)",
+		sc.lString, sc.rString, sc.rType.String(), sc.functionStack)
+}
+
+func makeSetConditions(tokens []token) (set []setCondition, err error) {
+	parse := func(tokens []token) (setCondition, []token, error) {
+		var sc setCondition
+		if len(tokens) < 3 {
+			return sc, nil, errors.New(invalidQuery + "Not enough arguments in 'set' clause")
+		}
+
+		setOp := strings.ToLower(tokens[1].str)
+		switch setOp {
+		case "=":
+		default:
+			return sc, nil, errors.New(invalidQuery + "Unknown operation in 'set' clause: " + setOp)
+		}
+
+		if !tokens[0].isBareword {
+			return sc, nil, errors.New(invalidQuery + "Expected bareword at 'set' clause's lValue: " + tokens[0].str)
+		}
+
+		sc.lString = tokens[0].str
+		if !strings.HasPrefix(sc.lString, "$") {
+			return sc, nil, errors.New(invalidQuery + "Expected field variable name (starting with $) at 'set' clause's lValue: " + tokens[0].str)
+		}
+		sc.rType = Field
+
+		rString := tokens[2].str
+		// Seems like a function call?
+		if strings.HasSuffix(rString, ")") {
+			functionStack, functionArg, err := funcs.NewFunctionStack(tokens[2].str)
+			if err != nil {
+				return sc, nil, err
+			}
+			sc.functionStack = functionStack
+			sc.rType = FunctionStack
+			sc.rString = functionArg
+			return sc, tokens[3:], nil
+		}
+
+		sc.rString = rString
+		if f, err := strconv.ParseFloat(sc.rString, 64); err == nil {
+			sc.rFloat = f
+			sc.rType = Float
+		} else {
+			sc.rType = Field
+		}
+
+		return sc, tokens[3:], nil
+	}
+
+	for len(tokens) > 0 {
+		var sc setCondition
+		var err error
+
+		sc, tokens, err = parse(tokens)
+		if err != nil {
+			return nil, err
+		}
+
+		set = append(set, sc)
+		tokens = tokensConsumeOptional(tokens, ",")
+	}
+
+	return
+}