class CollectNameVisitor
super Visitor
+ # All the productions
var nprods = new Array[Nprod]
# Symbol table to associate things (prods and exprs) with their name
# Read the result of the visit here
var nfa = new Automaton.empty
+ # The current production, used to initialize priorities
+ var prod: nullable Production = null
+
+ # The current priority counter to name transformed productions
+ var pricpt: Int = 0
+
# Run the semantic analysis of the grammar
fun start(n: Node)
do
# First visit to collect names
enter_visit(n)
- # Second visit to use collectec names and build rhings
+ # Second visit to use collected names and build things
var v2 = new CheckNameVisitor(self)
v2.enter_visit(n)
- # Inline all the ?
+ # Inline all the `?`
gram.inline(v2.quesizes.values)
- # Inlile all the prods sufixed by '_imline' #TODO use a real keyword
+ # Inline all the prods suffixed by '_inline' #TODO use a real keyword
for p in gram.prods do
if not p.name.has_suffix("_inline") then continue
print "inline {p}"
# Build the NFA automaton
for t in gram.tokens do
- var nexpr = t.nexpr
- var nfa2
- if nexpr == null then
- nfa2 = new Automaton.epsilon
- for c in t.text.as(not null) do
- nfa2.concat(new Automaton.atom(c.ascii))
- end
- else
- nfa2 = nexpr.build_nfa
- end
+ var nfa2 = t.build_nfa
nfa2.tag_accept(t)
nfa.absorb(nfa2)
end
+
+ if not v2.ignoreds.is_empty then
+ var ign = new Token("Ignored")
+ var nfa2 = new Automaton.empty
+ for t in v2.ignoreds do
+ assert t isa Token
+ var nfa3 = t.build_nfa
+ nfa2.alternate(nfa3)
+ end
+ nfa2.tag_accept(ign)
+ nfa.absorb(nfa2)
+ end
+
end
redef fun visit(n) do n.accept_collect_prod(self)
# The collected element names, for the alternative
var elems_names = new Array[nullable String]
- # The collected elementname, for the nelem
+ # The collected element names, for the nelem
var elemname: nullable String = null
# Is the alternative transformed, for the alternative
var trans = false
+ # The current priority class
+ # Used the check, and transform the grammar
+ var pri: nullable Npriority = null
+
+ # Known ignored tokens
+ var ignoreds = new Array[Element]
+
# Known rejected tokens
var rejecteds = new Array[Element]
# Pool of elements that are modified with + (reuse them!)
- private var plusizes = new HashMap[Element, Production]
+ var plusizes = new HashMap[Element, Production]
# Create a + version of an element
fun plusize(e: Element): Production
end
# Pool of elements that are modified with ? (reuse them!)
- private var quesizes = new HashMap[Element, Production]
+ var quesizes = new HashMap[Element, Production]
# Create a ? version of an element
fun quesize(e: Element): Production
end
# The current nexpr, used to track dependency on named expressions (see `Nexpr::precs`)
- var nexpr: nullable Nexpr
+ var nexpr: nullable Nexpr = null
# The current production, used to initialize alternatives
- var prod: nullable Production
+ var prod: nullable Production = null
# The main visitor, used to access the grammar of the symbol table
var v1: CollectNameVisitor
- init(v1: CollectNameVisitor) do self.v1 = v1
redef fun visit(n) do n.accept_check_name_visitor(self)
end
# The associated NFA (cached, see `build_nfa`)
private var nfa: nullable Automaton
- # Build the NFA, possibily building the NFA of required expressions
+ # Build the NFA, possibly building the NFA of required expressions
# Print an error if there is a circular dependency
# The result is cached
fun build_nfa: Automaton do
end
redef class Nign
- # The named element
- var elem: nullable Element
-
redef fun accept_check_name_visitor(v) do
- var id = children[1].as(Nid)
- var name = id.text
- if not v.v1.names.has_key(name) then
- print "{id.position.to_s} Error: unknown name {name}"
- exit(1)
- abort
- end
- var node = v.v1.names[name]
- var elem: nullable Element
- if node isa Nprod then
- print "{id.position.to_s} Error: cannot ignore a production"
- exit(1)
- abort
- else if node isa Nexpr then
- elem = node.token
- if elem == null then
- elem = new Token("Ignored")
- elem.nexpr = node
- v.v1.gram.tokens.add(elem)
- node.token = elem
+ # Add elements to the ignored list
+ v.elems = v.ignoreds
+ super
+ for e in v.elems do
+ if e isa Production then
+ print "Error: cannot ignore {e}, it is a production"
+ exit(1)
+ abort
+ else if e isa Token then
+ # The token was build and registered during the visit
+ # So, unregister them, the big Ignored token will be build later
+ v.v1.gram.tokens.remove(e)
+ else
+ abort
end
- else
- abort
end
- self.elem = elem
end
end
end
redef class Nprod
- # The associated production
+ # The associated main production.
+ # i.e. the last priority class.
var prod: nullable Production
+ # The associated most-priority production.
+ # i.e. the first priority class.
+ # If there is no priority then `sub_prod == prod`.
+ var sub_prod: nullable Production
+
redef fun accept_collect_prod(v) do
var id = children.first.as(Nid)
var name = id.text
end
v.names[name] = self
v.nprods.add(self)
- prod = new Production(name)
- v.gram.prods.add(prod.as(not null))
+ var prod = new Production(name)
+ self.prod = prod
+ v.gram.prods.add(prod)
+
+ # Check priority block
+ var pris = children[4]
+ if pris isa Nodes[Npriority] then
+ var lastpri = pris.children.last
+ lastpri.is_last = true
+
+ v.pricpt = pris.children.length
+
+ # Create a new production for the first priority class
+ # The main production will be used for the last priority class
+ var spe = prod
+ prod = new Production(name + "$0")
+ prod.spe = spe
+ v.gram.prods.add(prod)
+ end
+ self.sub_prod = prod
+
+ v.prod = prod
+ super
+ v.prod = null
end
redef fun accept_check_name_visitor(v) do
- v.prod = prod
+ v.prod = sub_prod
super
v.prod = null
end
end
end
+redef class Npriority
+ # It is the last priority group?
+ var is_last = false
+
+ # The associated production
+ var prod: nullable Production
+
+ # The production in the with the next less priority class.
+ # `null` if there is no priority or if the first priority class.
+ var next: nullable Production
+
+ redef fun accept_collect_prod(v) do
+ var old = v.prod
+ assert old != null
+ var spe = old.spe
+ assert spe != null
+ if is_last then
+ prod = spe
+ else
+ v.pricpt -= 1
+ prod = new Production(spe.name + "${v.pricpt}")
+ prod.spe = spe
+ v.gram.prods.add(prod.as(not null))
+ end
+ next = old
+ v.prod = prod
+ super
+
+ end
+ redef fun accept_check_name_visitor(v) do
+ var old = v.prod
+ v.prod = prod
+ v.pri = self
+ super
+
+ # Inject a new alternative that goes to the next less priority class
+ var alt = prod.new_alt2(prod.name + "_" + prod.alts.length.to_s, [next.as(not null)])
+ alt.trans = true
+ alt.codes = [new CodePop]
+
+ v.pri = null
+ v.prod = old
+ end
+
+ # Check and transform `v.elems` for priority
+ private fun check_priority(v: CheckNameVisitor) is abstract
+end
+
+redef class Npriority_left
+ redef fun check_priority(v) do
+ var p = prod.spe or else prod
+ assert p != null
+ if v.elems.length < 2 or v.elems.first != p or v.elems.last != p then
+ print("Error: in a Left priority class, left and right must be the production")
+ exit(1)
+ end
+ v.elems.first = prod.as(not null)
+ v.elems.last = next.as(not null)
+ end
+end
+
+redef class Npriority_right
+ redef fun check_priority(v) do
+ var p = prod.spe or else prod
+ assert p != null
+ if v.elems.length < 2 or v.elems.first != p or v.elems.last != p then
+ print("Error: in a Right priority class, left and right must be the production")
+ exit(1)
+ end
+ v.elems.first = next.as(not null)
+ v.elems.last = prod.as(not null)
+ end
+end
+
+redef class Npriority_unary
+ redef fun check_priority(v) do
+ var p = prod.spe or else prod
+ assert p != null
+ if v.elems.length < 2 or (v.elems.first != p and v.elems.last != p) then
+ print("Error: in a Unary priority class, left or right must be the production")
+ exit(1)
+ end
+ if v.elems.first == p then v.elems.first = prod.as(not null)
+ if v.elems.last == p then v.elems.last = prod.as(not null)
+ end
+end
+
redef class Alternative
+ # The short name of the alternative.
+ # Used for errors
var short_name: nullable String
end
v.trans = false
v.elems = new Array[Element]
v.elems_names = new Array[nullable String]
+
super
+
+ var pri = v.pri
+ if pri != null then pri.check_priority(v)
+
var prod = v.prod.as(not null)
var prodabs = prod.spe
if prodabs == null then prodabs = prod
if name == null then
if v.trans then
name = prod.name + "_" + prod.alts.length.to_s
- else if prod.spe == null and prod.alts.is_empty then
+ else if prod.spe == null and prod.alts.is_empty and pri == null then
name = prod.name
prod.altone = true
else
end
name = prodabs.name + "_" + name
end
+
var alt = prod.new_alt2(name, v.elems)
alt.short_name = v.altname
alt.elems_names.add_all(v.elems_names)
do
assert self.elem == null
self.elem = elem
- if elem isa Token and v.rejecteds.has(elem) then
- if pos != null then
- print "{pos} Error: {elem.name} is already a rejected token."
- else
- print "Error: {elem.name} is already a rejected token."
+ if elem isa Token then
+ if v.ignoreds.has(elem) then
+ if pos != null then
+ print "{pos} Error: {elem.name} is already an ignored token."
+ else
+ print "Error: {elem.name} is already an ignored token."
+ end
+ exit(1)
+ end
+ if v.rejecteds.has(elem) then
+ if pos != null then
+ print "{pos} Error: {elem.name} is already a rejected token."
+ else
+ print "Error: {elem.name} is already a rejected token."
+ end
+ exit(1)
end
- exit(1)
end
v.elems.push(elem)
end
var nexpr: nullable Nexpr
# The associated text (if any, ie defined in the parser part)
var text: nullable String
+
+ # Build a NFA according to nexpr or text
+ # Does not tag it!
+ fun build_nfa: Automaton
+ do
+ var nexpr = self.nexpr
+ if nexpr != null then
+ assert self.text == null
+ return nexpr.build_nfa
+ end
+ var text = self.text
+ if text != null then
+ var nfa = new Automaton.epsilon
+ for c in text.chars do
+ nfa.concat(new Automaton.atom(c.code_point))
+ end
+ return nfa
+ end
+ abort
+ end
end
redef class Nnelem
set_elem(v, null, elem)
end
end
+
+redef class Ntree_part
+ redef fun accept_collect_prod(v) do
+ print "NOT YET IMPLEMENTED: `Tree` part; it is ignored"
+ # SKIP by doing nothing
+ end
+
+ redef fun accept_check_name_visitor(v) do
+ # SKIP by doing nothing
+ end
+end
nitlanguage / nit.git / blobdiff