--- /dev/null
+$ // This file is part of NIT ( http://www.nitlanguage.org ).
+$ //
+$ // Copyright 2008 Jean Privat <jean@pryen.org>
+$ // Based on algorithms developped for ( http://www.sablecc.org/ ).
+$ //
+$ // Licensed under the Apache License, Version 2.0 (the "License");
+$ // you may not use this file except in compliance with the License.
+$ // You may obtain a copy of the License at
+$ //
+$ // http://www.apache.org/licenses/LICENSE-2.0
+$ //
+$ // Unless required by applicable law or agreed to in writing, software
+$ // distributed under the License is distributed on an "AS IS" BASIS,
+$ // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+$ // See the License for the specific language governing permissions and
+$ // limitations under the License.
+
+$ template make_parser()
+
+# State of the parser automata as stored in the parser stack.
+private class State
+ # The internal state number
+ readable writable var _state: Int
+
+ # The node stored with the state in the stack
+ readable writable var _nodes: nullable Object
+
+ init(state: Int, nodes: nullable Object)
+ do
+ _state = state
+ _nodes = nodes
+ end
+end
+
+class Parser
+ super TablesCapable
+ # Associated lexer
+ var _lexer: Lexer
+
+ # Stack of pushed states and productions
+ var _stack: Array[State]
+
+ # Position in the stack
+ var _stack_pos: Int
+
+ # Create a new parser based on a given lexer
+ init(lexer: Lexer)
+ do
+ _lexer = lexer
+ _stack = new Array[State]
+ _stack_pos = -1
+ build_reduce_table
+ end
+
+ # Do a transition in the automata
+ private fun go_to(index: Int): Int
+ do
+ var state = state
+ var low = 1
+ var high = parser_goto(index, 0) - 1
+
+ while low <= high do
+ var middle = (low + high) / 2
+ var subindex = middle * 2 + 1 # +1 because parser_goto(index, 0) is the length
+
+ var goal = parser_goto(index, subindex)
+ if state < goal then
+ high = middle - 1
+ else if state > goal then
+ low = middle + 1
+ else
+ return parser_goto(index, subindex+1)
+ end
+ end
+
+ return parser_goto(index, 2) # Default value
+ end
+
+ # Push someting in the state stack
+ private fun push(numstate: Int, list_node: nullable Object)
+ do
+ var pos = _stack_pos + 1
+ _stack_pos = pos
+ if pos < _stack.length then
+ var state = _stack[pos]
+ state.state = numstate
+ state.nodes = list_node
+ else
+ _stack.push(new State(numstate, list_node))
+ end
+ end
+
+ # The current state
+ private fun state: Int
+ do
+ return _stack[_stack_pos].state
+ end
+
+ # Pop something from the stack state
+ private fun pop: nullable Object
+ do
+ var res = _stack[_stack_pos].nodes
+ _stack_pos = _stack_pos -1
+ return res
+ end
+
+ # Build and return a full AST.
+ fun parse: Start
+ do
+ push(0, null)
+
+ var lexer = _lexer
+ loop
+ var token = lexer.peek
+ if token isa PError then
+ return new Start(null, token)
+ end
+
+ var state = self.state
+ var index = token.parser_index
+ var action_type = parser_action(state, 2)
+ var action_value = parser_action(state, 3)
+
+ var low = 1
+ var high = parser_action(state, 0) - 1
+
+ while low <= high do
+ var middle = (low + high) / 2
+ var subindex = middle * 3 + 1 # +1 because parser_action(state, 0) is the length
+
+ var goal = parser_action(state, subindex)
+ if index < goal then
+ high = middle - 1
+ else if index > goal then
+ low = middle + 1
+ else
+ action_type = parser_action(state, subindex+1)
+ action_value = parser_action(state, subindex+2)
+ break
+ end
+ end
+
+ if action_type == 0 then # SHIFT
+ push(action_value, lexer.next)
+ else if action_type == 1 then # REDUCE
+ _reduce_table[action_value].action(self)
+ else if action_type == 2 then # ACCEPT
+ var node2 = lexer.next
+ assert node2 isa EOF
+ var node1 = pop
+ assert node1 isa ${/parser/prods/prod/@ename}
+ var node = new Start(node1, node2)
+ (new ComputeProdLocationVisitor).enter_visit(node)
+ return node
+ else if action_type == 3 then # ERROR
+ var node2 = new PParserError.init_parser_error("Syntax error: unexpected {token}.", token.location, token)
+ var node = new Start(null, node2)
+ return node
+ end
+ end
+ end
+
+ var _reduce_table: Array[ReduceAction]
+ private fun build_reduce_table
+ do
+ _reduce_table = new Array[ReduceAction].with_items(
+$ foreach {rules/rule}
+ new ReduceAction@index(@leftside)[-sep ','-]
+$ end foreach
+ )
+ end
+end
+
+redef class Prod
+ # Location on the first token after the start of a production
+ # So outside the production for epilon production
+ var _first_location: nullable Location
+end
+
+# Find location of production nodes
+# Uses existing token locations to infer location of productions.
+private class ComputeProdLocationVisitor
+ super Visitor
+ # Currenlty visited productions that need a first token
+ var _need_first_prods: Array[Prod] = new Array[Prod]
+
+ # Already visited epsilon productions that waits something after them
+ var _need_after_epsilons: Array[Prod] = new Array[Prod]
+
+ # Location of the last visited token in the current production
+ var _last_location: nullable Location = null
+
+ redef fun visit(n: ANode)
+ do
+ if n isa Token then
+ var loc = n.location
+ _last_location = loc
+
+ # Add a first token to productions that need one
+ if not _need_first_prods.is_empty then
+ for no in _need_first_prods do
+ no._first_location = loc
+ end
+ _need_first_prods.clear
+ end
+
+ # Find location for already visited epsilon production that need one
+ if not _need_after_epsilons.is_empty then
+ var loco = new Location(loc.file, loc.line_start, loc.line_start, loc.column_start, loc.column_start)
+ for no in _need_after_epsilons do
+ no.location = loco
+ end
+ _need_after_epsilons.clear
+ end
+ else
+ assert n isa Prod
+ _need_first_prods.add(n)
+
+ n.visit_all(self)
+
+ var startl = n._first_location
+ if startl != null then
+ # Non-epsilon production
+ var endl = _last_location
+ assert endl != null
+
+ n.location = new Location(startl.file, startl.line_start, endl.line_end, startl.column_start, endl.column_end)
+
+ if not _need_after_epsilons.is_empty then
+ var loc = new Location(endl.file, endl.line_end, endl.line_end, endl.column_end, endl.column_end)
+ for no in _need_after_epsilons do
+ # Epsilon production that finishes the current non-epsilon production
+ no.location = loc
+ end
+ _need_after_epsilons.clear
+ end
+ else
+ # Epsilon production in the middle or that finishes a parent non-epsilon production
+ _need_after_epsilons.add(n)
+ end
+ end
+ end
+
+ init do end
+end
+
+# Each reduca action has its own class, this one is the root of the hierarchy.
+private abstract class ReduceAction
+ fun action(p: Parser) is abstract
+ fun concat(l1, l2 : Array[Object]): Array[Object]
+ do
+ if l1.is_empty then return l2
+ l1.append(l2)
+ return l1
+ end
+ var _goto: Int
+ init(g: Int) do _goto = g
+end
+
+$ foreach {rules/rule}
+private class ReduceAction@index
+ super ReduceAction
+ redef fun action(p: Parser)
+ do
+ 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")}
+ assert ${translate(@result,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")} isa Array[Object]
+$ end
+$ when {@cmd='FETCHNODE'}
+ var ${translate(@result,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")} = ${translate(@from,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")}
+ assert ${translate(@result,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")} isa nullable @etype
+$ end
+$ when {@cmd='ADDNODE'}
+ if ${translate(@node,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")} != null then
+ ${translate(@tolist,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")}.add(${translate(@node,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")})
+ end
+$ end
+$ when {@cmd='ADDLIST'}
+ ${translate(@tolist,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")} = concat(${translate(@tolist,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")}, ${translate(@fromlist,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")})
+$ end
+$ when {@cmd='MAKELIST'}
+ var ${translate(@result,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")} = new Array[Object]
+$ end
+$ when {@cmd='MAKENODE'}
+$ if {count(arg)!=0}
+ var ${translate(@result,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")}: nullable @etype = new @etype.init_${translate(@etype,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")}(
+$ foreach {arg}
+$ if @null
+ null[-sep ','-]
+$ else
+ ${translate(.,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")}[-sep ','-]
+$ end
+$ end foreach
+ )
+$ else
+ var ${translate(@result,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")}: nullable @etype = new @etype.init_${translate(@etype,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")}
+$ end
+$ end
+$ when {@cmd='RETURNNODE'}
+$ if @null
+ node_list = null
+$ else
+ node_list = ${translate(@node,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")}
+$ end
+$ end
+$ when {@cmd='RETURNLIST'}
+ node_list = ${translate(@list,"ABCDEFGHIJKLMNOPQRSTUVWXYZ","abcdefghijklmnopqrstuvwxyz")}
+$ end
+$ end choose
+$ end foreach
+ p.push(p.go_to(_goto), node_list)
+ end
+end
+$ end foreach
+$ end template
+
+$ template make_parser_table()
+$ foreach {parser_data/action_table/row}
+static int parser_action_row${position()}[] = {
+ ${count(action)},
+$ foreach {action}
+ @from, @action, @to[-sep ','-]
+$ end foreach
+};
+$ end foreach
+
+const int* const parser_action_table[] = {
+$ foreach {parser_data/action_table/row}
+ parser_action_row${position()}[-sep ','-]
+$ end foreach
+};
+
+$ foreach {parser_data/goto_table/row}
+static int parser_goto_row${position()}[] = {
+ ${count(goto)},
+$ foreach {goto}
+ @from, @to[-sep ','-]
+$ end foreach
+};
+$ end foreach
+
+const int* const parser_goto_table[] = {
+$ foreach {parser_data/goto_table/row}
+ parser_goto_row${position()}[-sep ','-]
+$ end foreach
+};
+$ end template
nitlanguage / nit.git / blobdiff