Files
expr/operand-func.go
T

89 lines
2.2 KiB
Go

// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
// All rights reserved.
// operand-func.go
package expr
import (
"errors"
"git.portale-stac.it/go-pkg/expr/kern"
"git.portale-stac.it/go-pkg/expr/scan"
)
// -------- function call term
func newFuncCallTerm(tk *scan.Token, args []*scan.Term) *scan.Term {
var pos scan.TermPosition = scan.PosLeaf
if len(args) > 0 {
pos = scan.PosMultifix
}
return &scan.Term{
Tk: *tk,
Parent: nil,
Children: args,
Position: pos,
Priority: scan.PriValue,
EvalFunc: evalFuncCall,
}
}
// -------- eval func call
// func _evalFuncCall(ctx ExprContext, opTerm *term) (v any, err error) {
// name, _ := opTerm.Tk.Value.(string)
// params := make([]any, len(opTerm.Children), len(opTerm.Children)+5)
// for i, tree := range opTerm.Children {
// var param any
// if param, err = tree.Compute(ctx); err != nil {
// break
// }
// params[i] = param
// }
// if err == nil {
// v, err = CallFunction(ctx, name, params)
// }
// return
// }
func evalFuncCall(ctx kern.ExprContext, opTerm *scan.Term) (v any, err error) {
name, _ := opTerm.Tk.Value.(string)
v, err = kern.CallFunctionByTerm(ctx, name, opTerm)
return
}
// -------- function definition term
func newFuncDefTerm(tk *scan.Token, args []*scan.Term) *scan.Term {
return &scan.Term{
Tk: *tk, // value is the expression body
Parent: nil,
Children: args, // function params
Position: scan.PosLeaf,
Priority: scan.PriValue,
EvalFunc: evalFuncDef,
}
}
// -------- eval func def
func evalFuncDef(ctx kern.ExprContext, opTerm *scan.Term) (v any, err error) {
bodySpec := opTerm.Value()
if ast, ok := bodySpec.(*scan.Ast); ok {
paramList := make([]kern.ExprFuncParam, 0, len(opTerm.Children))
for _, param := range opTerm.Children {
var defValue any
flags := paramFlags(0)
if len(param.Children) > 0 {
flags |= PfDefault
if defValue, err = param.Children[0].Compute(ctx); err != nil {
return
}
}
info := NewFuncParamFlagDef(param.Source(), flags, defValue)
paramList = append(paramList, info)
}
v = newExprFunctor(ast, paramList, ctx)
} else {
err = errors.New("invalid function definition: the body specification must be an expression")
}
return
}