go-pkg/expr
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Expr's functions now support parameters with default value

Browse Source
This commit is contained in:
Celestino Amoroso
2024-06-01 19:56:40 +02:00
parent f66cd1fdb1
commit 9bba40f155
12 changed files with 180 additions and 247 deletions
Download Patch File Download Diff File Expand all files Collapse all files
parser.go
+27 -74
View File
@@ -23,34 +23,28 @@ func NewParser(ctx ExprContext) (p *parser) {
}
func (self *parser) parseFuncCall(scanner *scanner, allowVarRef bool, tk *Token) (tree *term, err error) {
// name, _ := tk.Value.(string)
// funcObj := self.ctx.GetFuncInfo(name)
// if funcObj == nil {
// err = fmt.Errorf("unknown function %s()", name)
// return
// }
// maxArgs := funcObj.MaxArgs()
// if maxArgs < 0 {
// maxArgs = funcObj.MinArgs() + 10
// }
// args := make([]*term, 0, maxArgs)
args := make([]*term, 0, 10)
itemExpected := false
lastSym := SymUnknown
for lastSym != SymClosedRound && lastSym != SymEos {
var subTree *ast
if subTree, err = self.parseItem(scanner, allowVarRef, SymComma, SymClosedRound); err == nil {
if subTree.root != nil {
args = append(args, subTree.root)
}
} else {
if subTree, err = self.parseItem(scanner, allowVarRef, SymComma, SymClosedRound); err != nil {
break
}
prev := scanner.Previous()
if subTree.root != nil {
args = append(args, subTree.root)
} else if itemExpected {
err = prev.ErrorExpectedGot("function-param-value")
break
}
itemExpected = prev.Sym == SymComma
lastSym = scanner.Previous().Sym
}
if err == nil {
// TODO Check arguments
if lastSym != SymClosedRound {
err = errors.New("unterminate arguments list")
err = errors.New("unterminated arguments list")
} else {
tree = newFuncCallTerm(tk, args)
}
@@ -58,62 +52,12 @@ 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
args := make([]*term, 0)
lastSym := SymUnknown
defaultParamsStarted := false
itemExpected := false
tk := scanner.Previous()
for lastSym != SymClosedRound && lastSym != SymEos {
@@ -122,9 +66,20 @@ func (self *parser) parseFuncDef(scanner *scanner) (tree *term, err error) {
param := newTerm(tk)
args = append(args, param)
tk = scanner.Next()
if tk.Sym == SymEqual {
var paramExpr *ast
defaultParamsStarted = true
if paramExpr, err = self.parseItem(scanner, false, SymComma, SymClosedRound); err != nil {
break
}
param.forceChild(paramExpr.root)
} else if defaultParamsStarted {
err = tk.Errorf("can't mix default and non-default parameters")
break
}
} else if itemExpected {
prev := scanner.Previous()
err = prev.ErrorExpectedGot("function-param")
err = prev.ErrorExpectedGot("function-param-spec")
break
}
lastSym = scanner.Previous().Sym
@@ -143,7 +98,6 @@ func (self *parser) parseFuncDef(scanner *scanner) (tree *term, err error) {
}
}
if err == nil {
// TODO Check arguments
if scanner.Previous().Sym != SymClosedBrace {
err = scanner.Previous().ErrorExpectedGot("}")
} else {
@@ -225,7 +179,6 @@ func (self *parser) parseIterDef(scanner *scanner, allowVarRef bool) (subtree *t
itemExpected = lastSym == SymComma
}
if err == nil {
// TODO Check arguments
if lastSym != SymClosedRound {
err = scanner.Previous().ErrorExpectedGot(")")
} else {
@@ -252,7 +205,6 @@ func (self *parser) parseDictKey(scanner *scanner, allowVarRef bool) (key any, e
key = tk.Value
}
} else {
// err = tk.Errorf("expected dictionary key or closed brace, got %q", tk)
err = tk.ErrorExpectedGot("dictionary-key or }")
}
return
@@ -290,7 +242,6 @@ func (self *parser) parseDictionary(scanner *scanner, allowVarRef bool) (subtree
itemExpected = lastSym == SymComma
}
if err == nil {
// TODO Check arguments
if lastSym != SymClosedBrace {
err = scanner.Previous().ErrorExpectedGot("}")
} else {
@@ -394,6 +345,8 @@ func (self *parser) parseGeneral(scanner *scanner, allowForest bool, allowVarRef
if allowForest {
tree.ToForest()
firstToken = true
currentTerm = nil
selectorTerm = nil
continue
} else {
err = tk.Errorf(`unexpected token %q, expected ",", "]", or ")"`, tk.source)