moved scanner sources to package 'scan'

operator-context.go

@@ -6,29 +6,30 @@ package expr
 
 import (
 	"git.portale-stac.it/go-pkg/expr/kern"
+	"git.portale-stac.it/go-pkg/expr/scan"
 )
 
 //-------- context term
 
-func newContextTerm(tk *Token) (inst *term) {
-	return &term{
-		tk:       *tk,
-		children: make([]*term, 0, 1),
-		position: posPrefix,
-		priority: priIncDec,
-		evalFunc: evalContextValue,
+func newContextTerm(tk *scan.Token) (inst *scan.Term) {
+	return &scan.Term{
+		Tk:       *tk,
+		Children: make([]*scan.Term, 0, 1),
+		Position: scan.PosPrefix,
+		Priority: scan.PriIncDec,
+		EvalFunc: evalContextValue,
 	}
 }
 
-func evalContextValue(ctx kern.ExprContext, opTerm *term) (v any, err error) {
+func evalContextValue(ctx kern.ExprContext, opTerm *scan.Term) (v any, err error) {
 	var childValue any
 
 	var sourceCtx kern.ExprContext
-	if len(opTerm.children) == 0 {
+	if len(opTerm.Children) == 0 {
 		sourceCtx = ctx
-	} else if opTerm.children[0].symbol() == SymVariable && opTerm.children[0].Source() == "global" {
+	} else if opTerm.Children[0].Symbol() == scan.SymVariable && opTerm.Children[0].Source() == "global" {
 		sourceCtx = ctx.GetGlobal()
-	} else if childValue, err = opTerm.evalPrefix(ctx); err == nil {
+	} else if childValue, err = opTerm.EvalPrefix(ctx); err == nil {
 		if dc, ok := childValue.(*dataCursor); ok {
 			sourceCtx = dc.ctx
 		}
@@ -53,12 +54,12 @@ func evalContextValue(ctx kern.ExprContext, opTerm *term) (v any, err error) {
 			v = d
 		}
 	} else {
-		err = opTerm.errIncompatiblePrefixPostfixType(childValue)
+		err = opTerm.ErrIncompatiblePrefixPostfixType(childValue)
 	}
 	return
 }
 
 // init
 func init() {
-	registerTermConstructor(SymDoubleDollar, newContextTerm)
+	scan.RegisterTermConstructor(scan.SymDoubleDollar, newContextTerm)
 }