go-pkg/expr
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parser.go: simplified the parser of the function parameters

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This commit is contained in:
Celestino Amoroso 2024-05-04 19:10:02 +02:00
parent f9ed5776cd
commit 0fdd51049d
1 changed files with 60 additions and 15 deletions
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71
parser.go
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@ -58,6 +58,57 @@ func (self *parser) parseFuncCall(scanner *scanner, allowVarRef bool, tk *Token)
return
}
// func (self *parser) parseFuncDef(scanner *scanner) (tree *term, err error) {
// // Example: "add = func(x,y) {x+y}
// var body *ast
// args := make([]*term, 0)
// lastSym := SymUnknown
// itemExpected := false
// tk := scanner.Previous()
// for lastSym != SymClosedRound && lastSym != SymEos {
// var subTree *ast
// if subTree, err = self.parseItem(scanner, true, SymComma, SymClosedRound); err == nil {
// if subTree.root != nil {
// if subTree.root.symbol() == SymIdentifier {
// args = append(args, subTree.root)
// } else {
// err = tk.ErrorExpectedGotString("param-name", subTree.root.String())
// }
// } else if itemExpected {
// prev := scanner.Previous()
// err = prev.ErrorExpectedGot("function-param")
// break
// }
// } else {
// break
// }
// lastSym = scanner.Previous().Sym
// itemExpected = lastSym == SymComma
// }
// if err == nil && lastSym != SymClosedRound {
// err = tk.ErrorExpectedGot(")")
// }
// if err == nil {
// tk = scanner.Next()
// if tk.Sym == SymOpenBrace {
// body, err = self.parseGeneral(scanner, true, true, SymClosedBrace)
// } else {
// err = tk.ErrorExpectedGot("{")
// }
// }
// if err == nil {
// // TODO Check arguments
// if scanner.Previous().Sym != SymClosedBrace {
// err = scanner.Previous().ErrorExpectedGot("}")
// } else {
// tk = scanner.makeValueToken(SymExpression, "", body)
// tree = newFuncDefTerm(tk, args)
// }
// }
// return
// }
func (self *parser) parseFuncDef(scanner *scanner) (tree *term, err error) {
// Example: "add = func(x,y) {x+y}
var body *ast
@ -66,20 +117,14 @@ func (self *parser) parseFuncDef(scanner *scanner) (tree *term, err error) {
itemExpected := false
tk := scanner.Previous()
for lastSym != SymClosedRound && lastSym != SymEos {
var subTree *ast
if subTree, err = self.parseItem(scanner, true, SymComma, SymClosedRound); err == nil {
if subTree.root != nil {
if subTree.root.symbol() == SymIdentifier {
args = append(args, subTree.root)
} else {
err = tk.ErrorExpectedGotString("param-name", subTree.root.String())
}
tk = scanner.Next()
if tk.IsSymbol(SymIdentifier) {
param := newTerm(tk, nil)
args = append(args, param)
tk = scanner.Next()
} else if itemExpected {
prev := scanner.Previous()
err = prev.ErrorExpectedGot("function-param", prev)
break
}
} else {
err = prev.ErrorExpectedGot("function-param")
break
}
lastSym = scanner.Previous().Sym
@ -91,7 +136,7 @@ func (self *parser) parseFuncDef(scanner *scanner) (tree *term, err error) {
}
if err == nil {
tk = scanner.Next()
if tk.Sym == SymOpenBrace {
if tk.IsSymbol(SymOpenBrace) {
body, err = self.parseGeneral(scanner, true, true, SymClosedBrace)
} else {
err = tk.ErrorExpectedGot("{")