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Eprx now supports range of indeces to extract parts of strings or lists

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This commit is contained in:
Celestino Amoroso
2024-05-26 06:19:08 +02:00
parent 691c213d17
commit 2c87d6bf9e
6 changed files with 215 additions and 53 deletions
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parser.go
+50 -22
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@@ -154,16 +154,34 @@ func (self *parser) parseFuncDef(scanner *scanner) (tree *term, err error) {
return
}
func (self *parser) parseList(scanner *scanner, allowVarRef bool) (subtree *term, err error) {
func (self *parser) parseList(scanner *scanner, parsingIndeces bool, allowVarRef bool) (subtree *term, err error) {
r, c := scanner.lastPos()
args := make([]*term, 0)
lastSym := SymUnknown
itemExpected := false
for lastSym != SymClosedSquare && lastSym != SymEos {
var subTree *ast
zeroRequired := scanner.current.Sym == SymColon
if subTree, err = self.parseItem(scanner, allowVarRef, SymComma, SymClosedSquare); err == nil {
if subTree.root != nil {
args = append(args, subTree.root)
root := subTree.root
if root != nil {
if !parsingIndeces && root.symbol() == SymColon {
err = root.Errorf("unexpected range expression")
break
}
args = append(args, root)
if parsingIndeces && root.symbol() == SymColon && zeroRequired { //len(root.children) == 0 {
if len(root.children) == 1 {
root.children = append(root.children, root.children[0])
} else if len(root.children) > 1 {
err = root.Errorf("invalid range specification")
break
}
zeroTk := NewValueToken(root.tk.row, root.tk.col, SymInteger, "0", int64(0))
zeroTerm := newTerm(zeroTk)
zeroTerm.setParent(root)
root.children[0] = zeroTerm
}
} else if itemExpected {
prev := scanner.Previous()
err = prev.ErrorExpectedGot("list-item")
@@ -176,7 +194,6 @@ func (self *parser) parseList(scanner *scanner, allowVarRef bool) (subtree *term
itemExpected = lastSym == SymComma
}
if err == nil {
// TODO Check arguments
if lastSym != SymClosedSquare {
err = scanner.Previous().ErrorExpectedGot("]")
} else {
@@ -295,7 +312,7 @@ func (self *parser) parseSelectorCase(scanner *scanner, allowVarRef bool, defaul
err = tk.Errorf("case list in default clause")
return
}
if filterList, err = self.parseList(scanner, allowVarRef); err != nil {
if filterList, err = self.parseList(scanner, false, allowVarRef); err != nil {
return
}
tk = scanner.Next()
@@ -353,6 +370,14 @@ func (self *parser) Parse(scanner *scanner, termSymbols ...Symbol) (tree *ast, e
return self.parseGeneral(scanner, true, false, termSymbols...)
}
func couldBeACollection(t *term) bool {
var sym = SymUnknown
if t != nil {
sym = t.symbol()
}
return sym == SymList || sym == SymString || sym == SymDict || sym == SymExpression || sym == SymVariable
}
func (self *parser) parseGeneral(scanner *scanner, allowForest bool, allowVarRef bool, termSymbols ...Symbol) (tree *ast, err error) {
var selectorTerm *term = nil
var currentTerm *term = nil
@@ -402,12 +427,9 @@ func (self *parser) parseGeneral(scanner *scanner, allowForest bool, allowVarRef
}
case SymOpenSquare:
var listTerm *term
if listTerm, err = self.parseList(scanner, allowVarRef); err == nil {
var sym = SymUnknown
if currentTerm != nil {
sym = currentTerm.symbol()
}
if sym == SymList || sym == SymString || sym == SymDict || sym == SymExpression || sym == SymVariable {
parsingIndeces := couldBeACollection(currentTerm)
if listTerm, err = self.parseList(scanner, parsingIndeces, allowVarRef); err == nil {
if parsingIndeces {
indexTk := NewToken(listTerm.tk.row, listTerm.tk.col, SymIndex, listTerm.source())
indexTerm := newTerm(indexTk)
if err = tree.addTerm(indexTerm); err == nil {
@@ -419,10 +441,14 @@ func (self *parser) parseGeneral(scanner *scanner, allowForest bool, allowVarRef
currentTerm = listTerm
}
case SymOpenBrace:
var mapTerm *term
if mapTerm, err = self.parseDictionary(scanner, allowVarRef); err == nil {
err = tree.addTerm(mapTerm)
currentTerm = mapTerm
if currentTerm != nil && currentTerm.symbol() == SymColon {
err = currentTerm.Errorf(`selector-case outside of a selector context`)
} else {
var mapTerm *term
if mapTerm, err = self.parseDictionary(scanner, allowVarRef); err == nil {
err = tree.addTerm(mapTerm)
currentTerm = mapTerm
}
}
case SymEqual:
if err = checkPrevSymbol(lastSym, SymIdentifier, tk); err == nil {
@@ -452,14 +478,16 @@ func (self *parser) parseGeneral(scanner *scanner, allowForest bool, allowVarRef
}
case SymColon, SymDoubleColon:
var caseTerm *term
if selectorTerm == nil {
err = tk.Errorf("selector-case outside of a selector context")
} else if caseTerm, err = self.parseSelectorCase(scanner, allowVarRef, tk.Sym == SymDoubleColon); err == nil {
addSelectorCase(selectorTerm, caseTerm)
currentTerm = caseTerm
if tk.Sym == SymDoubleColon {
selectorTerm = nil
if selectorTerm != nil {
if caseTerm, err = self.parseSelectorCase(scanner, allowVarRef, tk.Sym == SymDoubleColon); err == nil {
addSelectorCase(selectorTerm, caseTerm)
currentTerm = caseTerm
if tk.Sym == SymDoubleColon {
selectorTerm = nil
}
}
} else {
currentTerm, err = tree.addToken2(tk)
}
default:
currentTerm, err = tree.addToken2(tk)