func (buffer *lexBuffer) factor() *types.TreeNode {
var node *types.TreeNode
var err error
switch buffer.token.TokenType {
case types.NUM:
node = newExpNode(types.ConstK, buffer.token.Lineno)
if buffer.token.TokenType == types.NUM {
node.Val, err = strconv.Atoi(buffer.token.TokenString)
if err != nil {
panic(err)
}
}
buffer.match(types.NUM)
case types.ID:
node = newExpNode(types.IdK, buffer.token.Lineno)
if buffer.token.TokenType == types.ID {
node.Name = buffer.token.TokenString
}
buffer.match(types.ID)
case types.STRING:
node = newExpNode(types.StringK, buffer.token.Lineno)
node.ValString = buffer.token.TokenString
buffer.match(types.STRING)
case types.LPAREN:
buffer.match(types.LPAREN)
node = buffer.exp()
buffer.match(types.RPAREN)
default:
syntaxError(buffer.token)
}
return node
}
func (buffer *lexBuffer) lexSequence() *types.TreeNode {
var node, p, q *types.TreeNode = nil, nil, nil
for buffer.token.TokenType != types.ENDFILE {
if buffer.token.TokenType == types.END ||
buffer.token.TokenType == types.ELSE ||
buffer.token.TokenType == types.UNTIL {
buffer.nextToken()
}
if buffer.token.TokenType == types.ENDFILE {
break
}
p = buffer.stmtSequence()
if node == nil {
node = p
} else {
q = node
for q.Sibling != nil {
q = q.Sibling
}
q.Sibling = p
}
}
return node
}
func checkNode(buf *buffer, node *types.TreeNode) {
switch node.Node {
case types.ExpK:
if node.Exp == types.OpK {
if node.Children[0].Type != types.Integer || node.Children[1].Type != types.Integer {
typeError(node.Lineno, locale.Locale.AnalyzeTypeOpError)
}
if node.Op == types.EQ || node.Op == types.LT {
node.Type = types.Boolean
} else {
node.Type = types.Integer
}
} else if node.Exp == types.ConstK || node.Exp == types.IdK {
node.Type = types.Integer
} else if node.Exp == types.StringK {
node.Type = types.String
}
case types.StmtK:
switch node.Stmt {
case types.IfK:
if node.Children[0].Type == types.Integer {
typeError(node.Lineno, locale.Locale.AnalyzeTypeIfError)
}
case types.AssignK:
if node.Children[0].Type != types.Integer {
typeError(node.Lineno, locale.Locale.AnalyzeTypeAssignError)
}
case types.WriteK:
if node.Children[0].Type != types.Integer && node.Children[0].Type != types.String {
typeError(node.Lineno, locale.Locale.AnalyzeTypeWriteError)
}
case types.RepeatK:
if node.Children[0].Type == types.Integer {
typeError(node.Lineno, locale.Locale.AnalyzeTypeRepeatError)
}
}
}
}
func newExpNode(kind types.ExpKind, lineno int) *types.TreeNode {
node := new(types.TreeNode)
node.Children = make([]*types.TreeNode, 0, 0)
node.Sibling = nil
node.Node = types.ExpK
node.Exp = kind
node.Lineno = lineno
return node
}