# State of the parser automata as stored in the parser stack.
private class State
# The internal state number
- readable writable attr _state: Int
+ readable writable var _state: Int
# The node stored with the state in the stack
- readable writable attr _nodes: Object
+ readable writable var _nodes: nullable Object
- init(state: Int, nodes: Object)
+ init(state: Int, nodes: nullable Object)
do
_state = state
_nodes = nodes
class Parser
special ParserTable
# Associated lexer
- attr _lexer: Lexer
+ var _lexer: Lexer
# Stack of pushed states and productions
- attr _stack: Array[State]
+ var _stack: Array[State]
# Position in the stack
- attr _stack_pos: Int
+ var _stack_pos: Int
# Create a new parser based on a given lexer
init(lexer: Lexer)
end
# Do a transition in the automata
- private meth go_to(index: Int): Int
+ private fun go_to(index: Int): Int
do
var state = state
var table = _goto_table[index]
end
# Push someting in the state stack
- private meth push(numstate: Int, list_node: Object)
+ private fun push(numstate: Int, list_node: nullable Object)
do
var pos = _stack_pos + 1
_stack_pos = pos
end
# The current state
- private meth state: Int
+ private fun state: Int
do
return _stack[_stack_pos].state
end
# Pop something from the stack state
- private meth pop: Object
+ private fun pop: nullable Object
do
var res = _stack[_stack_pos].nodes
_stack_pos = _stack_pos -1
end
# Build and return a full AST.
- meth parse: Start
+ fun parse: Start
do
push(0, null)
- var ign: List[Token] = null
var lexer = _lexer
while true do
var token = lexer.peek
var last_line = token.line
if token isa PError then
- assert token isa PError
return new Start(null, token)
end
return node
end
end
- return null
+ abort
end
- attr _reduce_table: Array[ReduceAction]
- private meth build_reduce_table
+ var _reduce_table: Array[ReduceAction]
+ private fun build_reduce_table
do
_reduce_table = new Array[ReduceAction].with_items(
$ foreach {rules/rule}
# Find first and last tokens of production nodes
private class SearchTokensVisitor
special Visitor
- attr _untokenned_nodes: Array[Prod]
- attr _last_token: Token
- redef meth visit(n: PNode)
+ var _untokenned_nodes: Array[Prod]
+ var _last_token: nullable Token = null
+ redef fun visit(n: nullable PNode)
do
- if n isa Token then
- assert n isa Token
+ if n == null then
+ return
+ else if n isa Token then
_last_token = n
for no in _untokenned_nodes do
no.first_token = n
# Each reduca action has its own class, this one is the root of the hierarchy.
private abstract class ReduceAction
- meth action(p: Parser) is abstract
+ fun action(p: Parser) is abstract
end
$ foreach {rules/rule}
private class ReduceAction@index
special ReduceAction
- redef meth action(p: Parser)
+ redef fun action(p: Parser)
do
- var node_list: Object = null
+ var node_list: nullable Object = null
$ foreach {action}
$ choose
$ when {@cmd='POP'}
var ${translate(@result,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")} = p.pop
$ end
$ when {@cmd='FETCHLIST'}
- var ${translate(@result,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")} = ${translate(@from,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")}
+ var ${translate(@result,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")} = ${translate(@from,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")}
assert ${translate(@result,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")} isa Array[Object]
$ end
$ when {@cmd='FETCHNODE'}
var ${translate(@result,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")} = ${translate(@from,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")}
- assert ${translate(@result,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")} isa @etype
+ assert ${translate(@result,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")} isa nullable @etype
$ end
$ when {@cmd='ADDNODE'}
if ${translate(@node,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")} != null then
end
$ end
$ when {@cmd='ADDLIST'}
- if ${translate(@fromlist,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")} != null then
+# if ${translate(@fromlist,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")} != null then
if ${translate(@tolist,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")}.is_empty then
${translate(@tolist,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")} = ${translate(@fromlist,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")}
else
${translate(@tolist,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")}.append(${translate(@fromlist,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")})
end
- end
+# end
$ end
$ when {@cmd='MAKELIST'}
var ${translate(@result,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")} = new Array[Object]
$ end
$ when {@cmd='MAKENODE'}
- var ${translate(@result,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")} = new @etype.init_${translate(@etype,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")}(
+ var ${translate(@result,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")}: nullable @etype = new @etype.init_${translate(@etype,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")}(
$ foreach {arg}
$ if @null
null[-sep ','-]
$ template make_parser_tables()
# Parser that build a full AST
abstract class ParserTable
- attr _action_table: Array[Array[Int]] = null
- private meth build_action_table
+ var _action_table: Array[Array[Int]]
+ private fun build_action_table
do
_action_table = once [
$ foreach {parser_data/action_table/row}
end
$ foreach {parser_data/action_table/row}
- private meth action_table_row${position()}: Array[Int]
+ private fun action_table_row${position()}: Array[Int]
do
return [
$ foreach {action}
end
$ end foreach
- attr _goto_table: Array[Array[Int]] = null
- private meth build_goto_table
+ var _goto_table: Array[Array[Int]]
+ private fun build_goto_table
do
_goto_table = once [
$ foreach {parser_data/goto_table/row}
]
end
- private meth error_messages: Array[String]
+ private fun error_messages: Array[String]
do
return once [
$ foreach {parser_data/error_messages/msg}
]
end
- private meth errors: Array[Int]
+ private fun errors: Array[Int]
do
return once [
[-foreach {parser_data/errors/i}-]${.} [-sep ','-] [-end-]
]
end
+
+ init do end
end
$ end template
nitlanguage / nit.git / blobdiff