What is still generated is thus more minimal.
Signed-off-by: Jean Privat <jean@pryen.org>
module parser
intrude import parser_prod
+intrude import parser_work
import tables
-# 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 AError 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 AModule
- var node = new Start(node1, node2)
- (new ComputeProdLocationVisitor).enter_visit(node)
- return node
- else if action_type == 3 then # ERROR
- var node2 = new AParserError.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
+redef class Parser
+ redef fun build_reduce_table
do
_reduce_table = new Array[ReduceAction].with_items(
new ReduceAction0(0),
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
-
private class ReduceAction0
super ReduceAction
redef fun action(p: Parser)
--- /dev/null
+# This file is part of NIT ( http://www.nitlanguage.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.
+
+# Internal algorithm and data structures for the Nit parser
+module parser_work
+
+intrude import parser_prod
+
+# 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 AError 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 AModule
+ var node = new Start(node1, node2)
+ (new ComputeProdLocationVisitor).enter_visit(node)
+ return node
+ else if action_type == 3 then # ERROR
+ var node2 = new AParserError.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 is abstract
+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
module parser
intrude import parser_prod
+intrude import parser_work
import tables
$ call make_parser()
$ end output
$ 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
+redef class Parser
+ redef fun build_reduce_table
do
_reduce_table = new Array[ReduceAction].with_items(
$ foreach {rules/rule}
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
nitlanguage / nit.git / commitdiff