+++ /dev/null
-# This file is part of NIT ( http://www.nitlanguage.org ).
-#
-# Copyright 2008 Jean Privat <jean@pryen.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.
-
-# Analysis property bodies, statements and expressions
-package typing
-
-import syntax_base
-import escape
-import control_flow
-
-redef class MMSrcModule
- # Walk trough the module and type statments and expressions
- # Require than supermodules are processed
- fun do_typing(tc: ToolContext)
- do
- var tv = new TypingVisitor(tc, self)
- tv.enter_visit(node)
- end
-end
-
-# Typing visitor
-# * Associate local variables to nodes
-# * Distinguish method call and local variable access
-# * Resolve call and attribute access
-# * Check type conformance
-private class TypingVisitor
-special AbsSyntaxVisitor
- redef fun visit(n)
- do
- if n != null then n.accept_typing(self)
- end
-
- # Current knowledge about variables names and types
- fun variable_ctx: VariableContext do return _variable_ctx.as(not null)
- writable var _variable_ctx: nullable VariableContext
-
- # Non-bypassable knowledge about variables names and types
- fun base_variable_ctx: VariableContext do return _base_variable_ctx.as(not null)
- writable var _base_variable_ctx: nullable VariableContext
-
- # Current knowledge about escapable blocks
- readable writable var _escapable_ctx: EscapableContext = new EscapableContext(self)
-
- # The current reciever
- fun self_var: ParamVariable do return _self_var.as(not null)
- writable var _self_var: nullable ParamVariable
-
- # Block of the current method
- readable writable var _top_block: nullable AExpr
-
- # List of explicit invocation of constructors of super-classes
- readable writable var _explicit_super_init_calls: nullable Array[MMMethod]
-
- # Is a other constructor of the same class invoked
- readable writable var _explicit_other_init_call: Bool = false
-
- # Make the if_true_variable_ctx of the expression effective
- private fun use_if_true_variable_ctx(e: AExpr)
- do
- var ctx = e.if_true_variable_ctx
- if ctx != null then variable_ctx = ctx
- end
-
- # Make the if_false_variable_ctx of the expression effective
- private fun use_if_false_variable_ctx(e: AExpr)
- do
- var ctx = e.if_false_variable_ctx
- if ctx != null then variable_ctx = ctx
- end
-
- # Number of nested once
- readable writable var _once_count: Int = 0
-
- init(tc, module) do super
-
- private fun get_default_constructor_for(n: ANode, c: MMLocalClass, prop: MMSrcMethod): nullable MMMethod
- do
- var v = self
- #var prop = v.local_property
- #assert prop isa MMMethod
- var candidates = new Array[MMMethod]
- var false_candidates = new Array[MMMethod]
- var parity = prop.signature.arity
- for g in c.global_properties do
- if not g.is_init_for(c) then continue
- var gp = c[g]
- var gps = gp.signature_for(c.get_type)
- assert gp isa MMSrcMethod
- var garity = gps.arity
- if gp.name == prop.name then
- if garity == 0 or (parity == garity and prop.signature < gps) then
- return gp
- else
- false_candidates.add(gp)
- end
- else if garity == 0 and gp.name == once ("init".to_symbol) then
- candidates.add(gp)
- false_candidates.add(gp)
- else
- false_candidates.add(gp)
- end
- end
- if candidates.length == 1 then
- return candidates.first
- else if candidates.length > 0 then
- var a = new Array[String]
- for p in candidates do
- a.add("{p.full_name}{p.signature}")
- end
- v.error(n, "Error: Conflicting default constructor to call for {c}: {a.join(", ")}.")
- return null
- else if false_candidates.length > 0 then
- var a = new Array[String]
- for p in false_candidates do
- a.add("{p.full_name}{p.signature}")
- end
- v.error(n, "Error: there is no available compatible constrctor in {c}. Discarded candidates are {a.join(", ")}.")
- return null
- else
- v.error(n, "Error: there is no available compatible constrctor in {c}.")
- return null
- end
- end
-end
-
-
-###############################################################################
-
-redef class ANode
- private fun accept_typing(v: TypingVisitor)
- do
- accept_abs_syntax_visitor(v)
- after_typing(v)
- end
- private fun after_typing(v: TypingVisitor) do end
-end
-
-redef class AClassdef
- redef fun accept_typing(v)
- do
- v.variable_ctx = new RootVariableContext(v, self)
- v.base_variable_ctx = v.variable_ctx
- v.self_var = new ParamVariable("self".to_symbol, self)
- v.self_var.stype = local_class.get_type
- super
- end
-end
-
-redef class APropdef
- redef fun self_var do return _self_var.as(not null)
- var _self_var: nullable ParamVariable
-end
-
-redef class AAttrPropdef
- redef fun accept_typing(v)
- do
- var old_var_ctx = v.variable_ctx
- v.variable_ctx = old_var_ctx.sub(self)
- _self_var = v.self_var
- super
- if n_expr != null then
- v.check_conform_expr(n_expr.as(not null), prop.signature.return_type.as(not null))
- end
- v.variable_ctx = old_var_ctx
- end
-end
-
-redef class AMethPropdef
- redef fun accept_typing(v)
- do
- var old_var_ctx = v.variable_ctx
- v.variable_ctx = old_var_ctx.sub(self)
- _self_var = v.self_var
- super
- v.variable_ctx = old_var_ctx
- end
-end
-
-redef class AConcreteMethPropdef
- redef fun after_typing(v)
- do
- super
- if v.variable_ctx.unreash == false and method.signature.return_type != null then
- v.error(self, "Control error: Reached end of function (a 'return' with a value was expected).")
- end
- end
-end
-
-redef class AConcreteInitPropdef
- redef fun accept_typing(v)
- do
- v.top_block = n_block
- v.explicit_super_init_calls = explicit_super_init_calls
- v.explicit_other_init_call = false
- super
- end
-
- redef fun after_typing(v)
- do
- super
- if v.explicit_other_init_call or method.global.intro != method then
- # TODO: something?
- else
- var i = 0
- var l = explicit_super_init_calls.length
- var cur_m: nullable MMMethod = null
- var cur_c: nullable MMLocalClass = null
- if i < l then
- cur_m = explicit_super_init_calls[i]
- cur_c = cur_m.global.intro.local_class.for_module(v.module)
- end
- var j = 0
- while j < v.local_class.cshe.direct_greaters.length do
- var c = v.local_class.cshe.direct_greaters[j]
- if c.global.is_interface or c.global.is_universal or c.global.is_mixin then
- j += 1
- else if cur_c != null and (c.cshe <= cur_c or cur_c.global.is_mixin) then
- if c == cur_c then j += 1
- super_init_calls.add(cur_m.as(not null))
- i += 1
- if i < l then
- cur_m = explicit_super_init_calls[i]
- cur_c = cur_m.global.intro.local_class.for_module(v.module)
- else
- cur_m = null
- cur_c = null
- end
- else
- var p = v.get_default_constructor_for(self, c, method)
- if p != null then
- super_init_calls.add(p)
- end
- j += 1
- end
- end
- end
- end
-end
-
-redef class AParam
- redef fun after_typing(v)
- do
- v.variable_ctx.add(variable)
- end
-end
-
-redef class AClosureDecl
- # The corresponding escapable object
- readable var _escapable: nullable EscapableBlock
-
- redef fun accept_typing(v)
- do
- # Register the closure for ClosureCallExpr
- v.variable_ctx.add(variable)
-
- var old_var_ctx = v.variable_ctx
- var old_base_var_ctx = v.base_variable_ctx
- v.base_variable_ctx = v.variable_ctx
- v.variable_ctx = v.variable_ctx.sub(self)
-
- var escapable = new EscapableClosure(self, variable.closure, null)
- _escapable = escapable
- v.escapable_ctx.push(escapable, null)
-
- super
-
- if n_expr != null then
- if v.variable_ctx.unreash == false then
- if variable.closure.signature.return_type != null then
- v.error(self, "Control error: Reached end of block (a 'continue' with a value was expected).")
- else if variable.closure.is_break then
- v.error(self, "Control error: Reached end of break block (an 'abort' was expected).")
- end
- end
- end
-
- old_var_ctx.merge(v.variable_ctx)
- v.variable_ctx = old_var_ctx
- v.base_variable_ctx = old_base_var_ctx
- v.escapable_ctx.pop
- end
-end
-
-redef class AType
- redef fun stype: MMType do return _stype.as(not null)
- redef fun is_typed: Bool do return _stype != null
- var _stype: nullable MMType
-
- redef fun after_typing(v)
- do
- _stype = get_stype(v)
- end
-end
-
-redef class AExpr
- redef readable var _is_typed: Bool = false
- redef fun is_statement: Bool do return _stype == null
- redef fun stype
- do
- if not is_typed then
- print "{location}: not is_typed"
- abort
- end
- if is_statement then
- print "{location}: is_statement"
- abort
- end
- return _stype.as(not null)
- end
- var _stype: nullable MMType
-
- redef fun after_typing(v)
- do
- # Default behavior is to be happy
- _is_typed = true
- end
-
- # Is the expression the implicit receiver
- fun is_implicit_self: Bool do return false
-
- # Is the expression the current receiver (implicit or explicit)
- fun is_self: Bool do return false
-
- # The variable accessed is any
- fun its_variable: nullable Variable do return null
-
- # The variable type information if current boolean expression is true
- readable private var _if_true_variable_ctx: nullable VariableContext
-
- # The variable type information if current boolean expression is false
- readable private var _if_false_variable_ctx: nullable VariableContext
-end
-
-redef class AVardeclExpr
- var _variable: nullable VarVariable
- redef fun variable do return _variable.as(not null)
-
- redef fun after_typing(v)
- do
- var va = new VarVariable(n_id.to_symbol, self)
- _variable = va
- v.variable_ctx.add(va)
- if n_expr != null then v.variable_ctx.mark_is_set(va)
-
- if n_type != null then
- if not n_type.is_typed then return
- va.stype = n_type.stype
- if n_expr != null then
- v.check_conform_expr(n_expr.as(not null), va.stype)
- end
- else
- if not v.check_expr(n_expr.as(not null)) then return
- va.stype = n_expr.stype
- end
- _is_typed = true
- end
-end
-
-redef class ABlockExpr
- redef fun accept_typing(v)
- do
- var old_var_ctx = v.variable_ctx
- v.variable_ctx = v.variable_ctx.sub(self)
-
- for e in n_expr do
- if v.variable_ctx.unreash and not v.variable_ctx.already_unreash then
- v.variable_ctx.already_unreash = true
- v.warning(e, "Warning: unreachable statement.")
- end
- v.enter_visit(e)
- end
-
- old_var_ctx.merge(v.variable_ctx)
- v.variable_ctx = old_var_ctx
- _is_typed = true
- end
-end
-
-redef class AReturnExpr
- redef fun after_typing(v)
- do
- v.variable_ctx.unreash = true
- var t = v.local_property.signature.return_type
- var e = n_expr
- if e == null and t != null then
- v.error(self, "Error: Return without value in a function.")
- else if e != null and t == null then
- v.error(self, "Error: Return with value in a procedure.")
- else if e != null and t != null then
- v.check_conform_expr(e, t)
- end
- _is_typed = true
- end
-end
-
-redef class AContinueExpr
- redef fun after_typing(v)
- do
- v.variable_ctx.unreash = true
- var esc = compute_escapable_block(v.escapable_ctx)
- if esc == null then return
-
- if esc.is_break_block then
- v.error(self, "Error: cannot 'continue', only 'break'.")
- return
- end
-
- var t = esc.continue_stype
- if n_expr == null and t != null then
- v.error(self, "Error: continue with a value required in this block.")
- else if n_expr != null and t == null then
- v.error(self, "Error: continue without value required in this block.")
- else if n_expr != null and t != null then
- v.check_conform_expr(n_expr.as(not null), t)
- end
- _is_typed = true
- end
-end
-
-redef class ABreakExpr
- redef fun after_typing(v)
- do
- v.variable_ctx.unreash = true
- var esc = compute_escapable_block(v.escapable_ctx)
- if esc == null then return
-
- var bl = esc.break_list
- if n_expr == null and bl != null then
- v.error(self, "Error: break with a value required in this block.")
- else if n_expr != null and bl == null then
- v.error(self, "Error: break without value required in this block.")
- else if n_expr != null and bl != null then
- # Typing check can only be done later
- bl.add(n_expr.as(not null))
- end
- _is_typed = true
- end
-end
-
-redef class AAbortExpr
- redef fun after_typing(v)
- do
- v.variable_ctx.unreash = true
- _is_typed = true
- end
-end
-
-redef class ADoExpr
- # The corresponding escapable block
- readable var _escapable: nullable EscapableBlock
-
- redef fun accept_typing(v)
- do
- var escapable = new BreakOnlyEscapableBlock(self)
- _escapable = escapable
- v.escapable_ctx.push(escapable, n_label)
-
- super
-
- v.escapable_ctx.pop
- _is_typed = true
- end
-end
-
-redef class AIfExpr
- redef fun accept_typing(v)
- do
- var old_var_ctx = v.variable_ctx
- v.enter_visit(n_expr)
- v.check_conform_expr(n_expr, v.type_bool)
-
- # Prepare 'then' context
- v.use_if_true_variable_ctx(n_expr)
-
- # Process the 'then'
- if n_then != null then
- v.variable_ctx = v.variable_ctx.sub(n_then.as(not null))
- v.enter_visit(n_then)
- end
-
- # Remember what appened in the 'then'
- var then_var_ctx = v.variable_ctx
-
- # Prepare 'else' context
- v.variable_ctx = old_var_ctx
- v.use_if_false_variable_ctx(n_expr)
-
- # Process the 'else'
- if n_else != null then
- v.variable_ctx = v.variable_ctx.sub(n_else.as(not null))
- v.enter_visit(n_else)
- end
-
- # Merge 'then' and 'else' contexts
- old_var_ctx.merge2(then_var_ctx, v.variable_ctx, v.base_variable_ctx)
- v.variable_ctx = old_var_ctx
- _is_typed = true
- end
-end
-
-redef class AWhileExpr
- # The corresponding escapable block
- readable var _escapable: nullable EscapableBlock
-
- redef fun accept_typing(v)
- do
- var escapable = new EscapableBlock(self)
- _escapable = escapable
- v.escapable_ctx.push(escapable, n_label)
- var old_var_ctx = v.variable_ctx
- var old_base_var_ctx = v.base_variable_ctx
- v.base_variable_ctx = v.variable_ctx
- v.variable_ctx = v.variable_ctx.sub(self)
-
- # Process condition
- v.enter_visit(n_expr)
- v.check_conform_expr(n_expr, v.type_bool)
-
- # Prepare inside context (assert cond)
- v.use_if_true_variable_ctx(n_expr)
-
- # Process inside
- if n_block != null then
- v.variable_ctx = v.variable_ctx.sub(n_block.as(not null))
- v.enter_visit(n_block)
- end
-
- v.variable_ctx = old_var_ctx
- v.base_variable_ctx = old_base_var_ctx
- v.escapable_ctx.pop
- _is_typed = true
- end
-end
-
-redef class AForExpr
- var _variable: nullable AutoVariable
- redef fun variable do return _variable.as(not null)
-
- # The corresponding escapable block
- readable var _escapable: nullable EscapableBlock
-
- redef fun accept_typing(v)
- do
- var escapable = new EscapableBlock(self)
- _escapable = escapable
- v.escapable_ctx.push(escapable, n_label)
-
- var old_var_ctx = v.variable_ctx
- var old_base_var_ctx = v.base_variable_ctx
- v.base_variable_ctx = v.variable_ctx
- v.variable_ctx = v.variable_ctx.sub(self)
- var va = new AutoVariable(n_id.to_symbol, self)
- _variable = va
- v.variable_ctx.add(va)
-
- # Process collection
- v.enter_visit(n_expr)
-
- if not v.check_conform_expr(n_expr, v.type_collection) then return
- var expr_type = n_expr.stype
-
- # Get iterator
- var meth_iterator = v.get_method(expr_type, once "iterator".to_symbol)
- var iter_type = meth_iterator.signature_for(expr_type).return_type.as(not null)
- var meth_item = v.get_method(iter_type, once ("item".to_symbol))
- var va_stype = meth_item.signature_for(iter_type).return_type.as(not null)
- if not n_expr.is_self then va_stype = va_stype.not_for_self
- va.stype = va_stype
-
- # Body evaluation
- if n_block != null then v.enter_visit(n_block)
-
- # pop context
- v.variable_ctx = old_var_ctx
- v.base_variable_ctx = old_base_var_ctx
- v.escapable_ctx.pop
- _is_typed = true
- end
-end
-
-redef class AAssertExpr
- redef fun after_typing(v)
- do
- v.check_conform_expr(n_expr, v.type_bool)
- v.use_if_true_variable_ctx(n_expr)
- _is_typed = true
- end
-end
-
-redef class AVarFormExpr
- var _variable: nullable Variable
- redef fun variable do return _variable.as(not null)
-end
-
-redef class AVarExpr
- redef fun its_variable do return variable
-
- redef fun after_typing(v)
- do
- v.variable_ctx.check_is_set(self, variable)
- _stype = v.variable_ctx.stype(variable)
- _is_typed = _stype != null
- end
-end
-
-redef class AVarAssignExpr
- redef fun after_typing(v)
- do
- v.variable_ctx.mark_is_set(variable)
- var t = v.variable_ctx.stype(variable)
-
- # Check the base type
- var btype = v.base_variable_ctx.stype(variable)
- if not v.check_conform_expr(n_value, btype) then return
-
- # Always cast
- v.variable_ctx.stype(variable) = n_value.stype
-
- _is_typed = true
- end
-end
-
-redef class AReassignFormExpr
- # Compute and check method used through the reassigment operator
- # On success return the static type of the result of the reassigment operator
- # Else display an error and return null
- private fun do_rvalue_typing(v: TypingVisitor, type_lvalue: nullable MMType): nullable MMType
- do
- if type_lvalue == null then
- return null
- end
- var name = n_assign_op.method_name
- var lc = type_lvalue.local_class
- if not lc.has_global_property_by_name(name) then
- v.error(self, "Error: Method '{name}' doesn't exists in {type_lvalue}.")
- return null
- end
- var prop = lc.select_method(name)
- prop.global.check_visibility(v, self, v.module, false)
- var psig = prop.signature_for(type_lvalue)
- _assign_method = prop
- if not v.check_conform_expr(n_value, psig[0].not_for_self) then return null
- return psig.return_type.not_for_self
- end
-
- redef fun assign_method do return _assign_method.as(not null)
- var _assign_method: nullable MMMethod
-end
-
-redef class AVarReassignExpr
- redef fun after_typing(v)
- do
- v.variable_ctx.check_is_set(self, variable)
- v.variable_ctx.mark_is_set(variable)
- var t = v.variable_ctx.stype(variable)
- var t2 = do_rvalue_typing(v, t)
- if t2 == null then return
-
- # Check the base type
- var btype = v.base_variable_ctx.stype(variable)
- if not v.check_conform(n_value, t2, btype) then return
-
- # Always cast
- v.variable_ctx.stype(variable) = t2
-
- _is_typed = true
- end
-end
-
-redef class AAssignOp
- fun method_name: Symbol is abstract
-end
-redef class APlusAssignOp
- redef fun method_name do return once "+".to_symbol
-end
-redef class AMinusAssignOp
- redef fun method_name do return once "-".to_symbol
-end
-
-redef class ASelfExpr
- var _variable: nullable ParamVariable
- redef fun variable do return _variable.as(not null)
-
- redef fun its_variable do return variable
-
- redef fun after_typing(v)
- do
- _variable = v.self_var
- _stype = v.variable_ctx.stype(variable)
- _is_typed = true
- end
-
- redef fun is_self do return true
-end
-
-redef class AImplicitSelfExpr
- redef fun is_implicit_self do return true
-end
-
-redef class AIfexprExpr
- redef fun accept_typing(v)
- do
- var old_var_ctx = v.variable_ctx
-
- # Process condition
- v.enter_visit(n_expr)
- v.check_conform_expr(n_expr, v.type_bool)
-
- # Prepare 'then' context
- v.use_if_true_variable_ctx(n_expr)
-
- # Process 'then'
- v.enter_visit(n_then)
-
- # Prepare 'else' context
- v.variable_ctx = old_var_ctx
- v.use_if_false_variable_ctx(n_expr)
-
- # Process 'else'
- v.enter_visit(n_else)
-
- var stype = v.check_conform_multiexpr(null, [n_then, n_else])
- if stype == null then return
-
- _stype = stype
- _is_typed = true
- end
-end
-
-redef class ABoolExpr
- redef fun after_typing(v)
- do
- _stype = v.type_bool
- _is_typed = true
- end
-end
-
-redef class AOrExpr
- redef fun accept_typing(v)
- do
- var old_var_ctx = v.variable_ctx
- var stype = v.type_bool
- _stype = stype
-
- # Process left operand
- v.enter_visit(n_expr)
-
- # Prepare right operand context
- v.use_if_false_variable_ctx(n_expr)
-
- # Process right operand
- v.enter_visit(n_expr2)
- if n_expr2.if_false_variable_ctx != null then
- _if_false_variable_ctx = n_expr2.if_false_variable_ctx
- else
- _if_false_variable_ctx = v.variable_ctx
- end
-
- v.variable_ctx = old_var_ctx
-
- v.check_conform_expr(n_expr, stype)
- v.check_conform_expr(n_expr2, stype)
- _stype = stype
- _is_typed = true
- end
-end
-
-redef class AAndExpr
- redef fun accept_typing(v)
- do
- var old_var_ctx = v.variable_ctx
- var stype = v.type_bool
-
- # Process left operand
- v.enter_visit(n_expr)
-
- # Prepare right operand context
- v.use_if_true_variable_ctx(n_expr)
-
- # Process right operand
- v.enter_visit(n_expr2)
- if n_expr2.if_true_variable_ctx != null then
- _if_true_variable_ctx = n_expr2.if_true_variable_ctx
- else
- _if_true_variable_ctx = v.variable_ctx
- end
-
- v.variable_ctx = old_var_ctx
-
- v.check_conform_expr(n_expr, stype)
- v.check_conform_expr(n_expr2, stype)
- _stype = stype
- _is_typed = true
- end
-end
-
-redef class ANotExpr
- redef fun after_typing(v)
- do
- v.check_conform_expr(n_expr, v.type_bool)
-
- # Invert if_true/if_false information
- _if_false_variable_ctx = n_expr._if_true_variable_ctx
- _if_true_variable_ctx = n_expr._if_false_variable_ctx
-
- _stype = v.type_bool
- _is_typed = true
- end
-end
-
-redef class AIntExpr
- redef fun after_typing(v)
- do
- _stype = v.type_int
- _is_typed = true
- end
-end
-
-redef class AFloatExpr
- redef fun after_typing(v)
- do
- _stype = v.type_float
- _is_typed = true
- end
-end
-
-redef class ACharExpr
- redef fun after_typing(v)
- do
- _stype = v.type_char
- _is_typed = true
- end
-end
-
-redef class AStringFormExpr
- redef fun after_typing(v)
- do
- _stype = v.type_string
- _is_typed = true
- end
-end
-
-redef class ASuperstringExpr
- redef fun atype do return _atype.as(not null)
- var _atype: nullable MMType
- redef fun after_typing(v)
- do
- var stype = v.type_string
- _stype = stype
- var atype = v.type_array(stype)
- _atype = atype
- _is_typed = true
- end
-end
-
-redef class ANullExpr
- redef fun after_typing(v)
- do
- _stype = v.type_none
- _is_typed = true
- end
-end
-
-redef class AArrayExpr
- redef fun after_typing(v)
- do
- var stype = v.check_conform_multiexpr(null, n_exprs)
- if stype != null then do_typing(v, stype)
- end
-
- private fun do_typing(v: TypingVisitor, element_type: MMType)
- do
- _stype = v.type_array(element_type)
- _is_typed = true
- end
-end
-
-redef class ARangeExpr
- redef fun after_typing(v)
- do
- if not v.check_expr(n_expr) or not v.check_expr(n_expr2) then return
- var ntype = n_expr.stype
- var ntype2 = n_expr2.stype
- if ntype < ntype2 then
- ntype = ntype2
- else if not ntype2 < ntype then
- v.error(self, "Type error: {ntype} incompatible with {ntype2}.")
- return
- end
- var dtype = v.type_discrete
- if not v.check_conform_expr(n_expr, dtype) or not v.check_conform_expr(n_expr2, dtype) then return
- _stype = v.type_range(ntype)
- _is_typed = true
- end
-end
-
-redef class ASuperExpr
- redef readable var _init_in_superclass: nullable MMMethod
- redef fun compute_raw_arguments do return n_args.to_a
- redef fun after_typing(v)
- do
- var precs: Array[MMLocalProperty] = v.local_property.prhe.direct_greaters
- if not precs.is_empty then
- v.local_property.need_super = true
- else if v.local_property.global.is_init then
- var base_precs = v.local_class.super_methods_named(v.local_property.name)
- for p in base_precs do
- if not p.global.is_init then
- v.error(self, "Error: {p.local_class}::{p} is not a constructor.")
- else
- precs.add(v.local_class[p.global])
- end
- end
- if precs.is_empty then
- v.error(self, "Error: No contructor named {v.local_property.name} in superclasses.")
- return
- else if precs.length > 1 then
- v.error(self, "Error: Conflicting contructors named {v.local_property.name} in superclasses: {precs.join(", ")}.")
- return
- end
- var p = base_precs.first
- assert p isa MMMethod
- _init_in_superclass = p
- register_super_init_call(v, p)
- if n_args.length > 0 then
- var signature = get_signature(v, v.self_var.stype.as(not null), p, true)
- process_signature(v, signature, p.name, compute_raw_arguments)
- end
- else
- v.error(self, "Error: No super method to call for {v.local_property}.")
- return
- end
-
- if precs.first.signature_for(v.self_var.stype.as(not null)).return_type != null then
- var stypes = new Array[MMType]
- var stype: nullable MMType = null
- for prop in precs do
- assert prop isa MMMethod
- var t = prop.signature_for(v.self_var.stype.as(not null)).return_type.for_module(v.module).adapt_to(v.local_property.signature.recv)
- stypes.add(t)
- if stype == null or stype < t then
- stype = t
- end
- end
- for t in stypes do
- v.check_conform(self, t, stype.as(not null))
- end
- _stype = stype
- end
- var p = v.local_property
- assert p isa MMSrcMethod
- _prop = p
- _is_typed = true
- end
-end
-
-redef class AAttrFormExpr
- redef fun prop do return _prop.as(not null)
- var _prop: nullable MMAttribute
-
- redef fun attr_type do return _attr_type.as(not null)
- var _attr_type: nullable MMType
-
- # Compute the attribute accessed
- private fun do_typing(v: TypingVisitor)
- do
- if not v.check_expr(n_expr) then return
- var type_recv = n_expr.stype
- var name = n_id.to_symbol
- var lc = type_recv.local_class
- if not lc.has_global_property_by_name(name) then
- v.error(self, "Error: Attribute {name} doesn't exists in {type_recv}.")
- return
- end
- var prop = lc.select_attribute(name)
- if v.module.visibility_for(prop.global.local_class.module) < 3 then
- v.error(self, "Error: Attribute {name} from {prop.global.local_class.module} is invisible in {v.module}")
- end
- _prop = prop
- var at = prop.signature_for(type_recv).return_type
- if not n_expr.is_self then at = at.not_for_self
- _attr_type = at
- end
-end
-
-redef class AAttrExpr
- redef fun after_typing(v)
- do
- do_typing(v)
- if _prop == null then return
- _stype = attr_type
- _is_typed = true
- end
-end
-
-redef class AAttrAssignExpr
- redef fun after_typing(v)
- do
- do_typing(v)
- if _prop == null then return
- if not v.check_conform_expr(n_value, attr_type) then return
- _is_typed = true
- end
-end
-
-redef class AAttrReassignExpr
- redef fun after_typing(v)
- do
- do_typing(v)
- if _prop == null then return
- var t = do_rvalue_typing(v, attr_type)
- if t == null then return
- v.check_conform(self, t, n_value.stype)
- _is_typed = true
- end
-end
-
-redef class AIssetAttrExpr
- redef fun after_typing(v)
- do
- do_typing(v)
- if _prop == null then return
- if attr_type.is_nullable then
- v.error(self, "Error: isset on a nullable attribute.")
- end
- _stype = v.type_bool
- _is_typed = true
- end
-end
-
-redef class AAbsAbsSendExpr
- # The signature of the called property
- redef fun prop_signature do return _prop_signature.as(not null)
- var _prop_signature: nullable MMSignature
-
- # Raw arguments used (without vararg transformation)
- redef fun raw_arguments: Array[AExpr]
- do
- var res = _raw_arguments_cache
- if res != null then
- return res
- else
- res = compute_raw_arguments
- if res == null then res = new Array[AExpr]
- _raw_arguments_cache = res
- return res
- end
- end
-
- var _raw_arguments_cache: nullable Array[AExpr] = null
-
- fun compute_raw_arguments: nullable Array[AExpr]
- do
- print "{location} no compute_raw_arguments"
- return null
- end
-
- # Check the conformity of a set of arguments `raw_args' to a signature.
- private fun process_signature(v: TypingVisitor, psig: MMSignature, name: Symbol, raw_args: nullable Array[AExpr]): Bool
- do
- var par_vararg = psig.vararg_rank
- var par_arity = psig.arity
- var raw_arity: Int
- if raw_args == null then raw_arity = 0 else raw_arity = raw_args.length
- if par_arity > raw_arity or (par_arity != raw_arity and par_vararg == -1) then
- v.error(self, "Error: arity missmatch; prototype is '{name}{psig}'.")
- return false
- end
- var arg_idx = 0
- for par_idx in [0..par_arity[ do
- var a: AExpr
- var par_type = psig[par_idx]
- if par_idx == par_vararg then
- for i in [0..(raw_arity-par_arity)] do
- a = raw_args[arg_idx]
- v.check_conform_expr(a, par_type)
- arg_idx = arg_idx + 1
- end
- else
- a = raw_args[arg_idx]
- v.check_conform_expr(a, par_type)
- arg_idx = arg_idx + 1
- end
- end
- return true
- end
-
- # Check the conformity of a set of defined closures
- private fun process_closures(v: TypingVisitor, psig: MMSignature, name: Symbol, cd: nullable Array[AClosureDef]): nullable MMType
- do
- var t = psig.return_type
- var cs = psig.closures # Declared closures
- var min_arity = 0
- for c in cs do
- if not c.is_optional then min_arity += 1
- end
- var arity = 0
- if cd != null then arity = cd.length
- if cs.length > 0 then
- if arity == 0 and min_arity > 0 then
- v.error(self, "Error: {name} requires {cs.length} blocks.")
- else if arity > cs.length or arity < min_arity then
- v.error(self, "Error: {name} requires {cs.length} blocks, {cd.length} found.")
- else
- # Initialize the break list if a value is required for breaks (ie. if the method is a function)
- var break_list: nullable Array[ABreakExpr] = null
- if t != null then break_list = new Array[ABreakExpr]
-
- # The n_label, is any in only set on the last decl
- var n_label = if arity > 0 then cd[arity-1].n_label else null
-
- # Process each closure definition
- for i in [0..arity[ do
- var cdi = cd[i]
- var cni = cdi.n_id.to_symbol
- var csi = psig.closure_named(cni)
- if csi != null then
- var esc = new EscapableClosure(cdi, csi, break_list)
- v.escapable_ctx.push(esc, n_label)
- cdi.accept_typing2(v, esc)
- v.escapable_ctx.pop
- else if cs.length == 1 then
- v.error(cdi.n_id, "Error: no closure named '!{cni}' in {name}; only closure is !{cs.first.name}.")
- else
- var a = new Array[String]
- for c in cs do
- a.add("!{c.name}")
- end
- v.error(cdi.n_id, "Error: no closure named '!{cni}' in {name}; only closures are {a.join(",")}.")
- end
- end
-
- # Check break type conformity
- if break_list != null then
- t = v.check_conform_multiexpr(t, break_list)
- end
- end
- else if arity != 0 then
- v.error(self, "Error: {name} does not require blocks.")
- end
- return t
- end
-end
-
-redef class AAbsSendExpr
- # Compute the called global property
- private fun do_typing(v: TypingVisitor, type_recv: MMType, is_implicit_self: Bool, recv_is_self: Bool, name: Symbol, raw_args: nullable Array[AExpr], closure_defs: nullable Array[AClosureDef])
- do
- var prop = get_property(v, type_recv, is_implicit_self, name)
- if prop == null then return
- var sig = get_signature(v, type_recv, prop, recv_is_self)
- if not process_signature(v, sig, prop.name, raw_args) then return
- var rtype = process_closures(v, sig, prop.name, closure_defs)
- if rtype == null and sig.return_type != null then return
- _prop = prop
- _prop_signature = sig
- _return_type = rtype
- end
-
- private fun get_property(v: TypingVisitor, type_recv: MMType, is_implicit_self: Bool, name: Symbol): nullable MMMethod
- do
- var lc = type_recv.local_class
- var prop: nullable MMMethod = null
- if lc.has_global_property_by_name(name) then prop = lc.select_method(name)
- if prop == null and v.local_property.global.is_init then
- var props = type_recv.local_class.super_methods_named(name)
- if props.length > 1 then
- v.error(self, "Error: Ambigous method name '{name}' for {props.join(", ")}. Use explicit designation.")
- return null
- else if props.length == 1 then
- var p = type_recv.local_class[props.first.global]
- assert p isa MMMethod
- prop = p
- end
-
- end
- if prop == null then
- if is_implicit_self then
- v.error(self, "Error: Method or variable '{name}' unknown in {type_recv}.")
- else
- v.error(self, "Error: Method '{name}' doesn't exists in {type_recv}.")
- end
- return null
- end
- return prop
- end
-
- # Get the signature for a local property and a receiver
- private fun get_signature(v: TypingVisitor, type_recv: MMType, prop: MMMethod, recv_is_self: Bool): MMSignature
- do
- prop.global.check_visibility(v, self, v.module, recv_is_self)
- var psig = prop.signature_for(type_recv)
- if not recv_is_self then psig = psig.not_for_self
- return psig
- end
-
- # The invoked method (once computed)
- redef fun prop do return _prop.as(not null)
- var _prop: nullable MMMethod
-
- # The return type (if any) (once computed)
- redef readable var _return_type: nullable MMType
-end
-
-# A possible call of constructor in a super class
-# Could be an explicit call or with the 'super' keyword
-redef class ASuperInitCall
- private fun register_super_init_call(v: TypingVisitor, property: MMMethod)
- do
- if parent != v.top_block and self != v.top_block then
- v.error(self, "Error: Constructor invocation {property} must not be in nested block.")
- end
- var cla = v.module[property.global.intro.local_class.global]
- var prev_class: nullable MMLocalClass = null
- var esic = v.explicit_super_init_calls.as(not null)
- if not esic.is_empty then
- prev_class = esic.last.global.intro.local_class
- end
- var order = v.local_class.cshe.reverse_linear_extension
- if cla == v.local_class then
- v.explicit_other_init_call = true
- else if not order.has(cla) then
- v.error(self, "Error: Constructor of class {cla} must be one in {order.join(", ")}.")
- else if cla == prev_class then
- v.error(self, "Error: Only one super constructor invocation of class {cla} is allowed.")
- else
- var last_is_found = prev_class == null
- for c in order do
- if c == prev_class then
- last_is_found = true
- else if c == cla then
- if not last_is_found then
- v.error(self, "Error: Constructor of {c} must be invoked before constructor of {prev_class}")
- end
- esic.add(property)
- break
- end
- end
- end
- end
-
-end
-
-redef class ANewExpr
- redef fun compute_raw_arguments do return n_args.to_a
- redef fun after_typing(v)
- do
- if not n_type.is_typed then return
- var t = n_type.stype
- if t.local_class.global.is_abstract then
- v.error(self, "Error: try to instantiate abstract class {t.local_class}.")
- return
- end
- var name: Symbol
- if n_id == null then
- name = once "init".to_symbol
- else
- name = n_id.to_symbol
- end
-
- do_typing(v, t, false, false, name, raw_arguments, null)
- if _prop == null then return
-
- if not prop.global.is_init then
- v.error(self, "Error: {prop} is not a constructor.")
- return
- end
- _stype = t
- _is_typed = true
- end
-end
-
-
-redef class ASendExpr
- # Name of the invoked property
- fun name: Symbol is abstract
-
- # Closure definitions
- redef fun closure_defs: nullable Array[AClosureDef] do return null
-
- redef fun after_typing(v)
- do
- do_all_typing(v)
- end
-
- private fun do_all_typing(v: TypingVisitor)
- do
- if not v.check_expr(n_expr) then return
- do_typing(v, n_expr.stype, n_expr.is_implicit_self, n_expr.is_self, name, raw_arguments, closure_defs)
- if _prop == null then return
- var prop = _prop.as(not null)
-
- if prop.global.is_init then
- if not v.local_property.global.is_init then
- v.error(self, "Error: try to invoke constructor {prop} in a method.")
- else if not n_expr.is_self then
- v.error(self, "Error: constructor {prop} is not invoken on 'self'.")
- else
- register_super_init_call(v, prop)
- end
- end
-
- _stype = return_type
- _is_typed = true
- end
-end
-
-redef class ASendReassignExpr
- redef fun read_prop do return _read_prop.as(not null)
- var _read_prop: nullable MMMethod
- redef fun do_all_typing(v)
- do
- if not v.check_expr(n_expr) then return
- var raw_args = raw_arguments
- do_typing(v, n_expr.stype, n_expr.is_implicit_self, n_expr.is_self, name, raw_args, null)
- var prop = _prop
- if prop == null then return
- if prop.global.is_init then
- if not v.local_property.global.is_init then
- v.error(self, "Error: try to invoke constructor {prop} in a method.")
- else if not n_expr.is_self then
- v.error(self, "Error: constructor {prop} is not invoken on 'self'.")
- end
- end
- var t = prop.signature_for(n_expr.stype).return_type.as(not null)
- if not n_expr.is_self then t = t.not_for_self
-
- var t2 = do_rvalue_typing(v, t)
- if t2 == null then return
- v.check_conform(self, t2, n_value.stype)
-
- _read_prop = prop
- raw_args = raw_args.to_a
- raw_args.add(n_value)
-
- do_typing(v, n_expr.stype, n_expr.is_implicit_self, n_expr.is_self, "{name}=".to_symbol, raw_args, null)
- if prop.global.is_init then
- if not v.local_property.global.is_init then
- v.error(self, "Error: try to invoke constructor {prop} in a method.")
- else if not n_expr.is_self then
- v.error(self, "Error: constructor {prop} is not invoken on 'self'.")
- end
- end
-
- _is_typed = true
- end
-end
-
-redef class ABinopExpr
- redef fun compute_raw_arguments do return [n_expr2]
-end
-redef class AEqExpr
- redef fun name do return once "==".to_symbol
- redef fun after_typing(v)
- do
- super
- if not n_expr.is_typed or not n_expr2.is_typed then return
- if n_expr.stype isa MMTypeNone and not n_expr2.stype.is_nullable or
- n_expr2.stype isa MMTypeNone and not n_expr.stype.is_nullable then
- v.warning(self, "Warning: comparaison between null and a non nullable value.")
- end
-
- if n_expr.stype isa MMTypeNone then
- try_to_isa(v, n_expr2)
- else if n_expr2.stype isa MMTypeNone then
- try_to_isa(v, n_expr)
- end
- end
-
- private fun try_to_isa(v: TypingVisitor, n: AExpr)
- do
- var variable = n.its_variable
- if variable != null then
- _if_false_variable_ctx = v.variable_ctx.sub_with(self, variable, n.stype.as_notnull)
- end
- end
-end
-redef class ANeExpr
- redef fun name do return once "!=".to_symbol
- redef fun after_typing(v)
- do
- super
- if not n_expr.is_typed or not n_expr2.is_typed then return
- if n_expr.stype isa MMTypeNone and not n_expr2.stype.is_nullable or
- n_expr2.stype isa MMTypeNone and not n_expr.stype.is_nullable then
- v.warning(self, "Warning: comparaison between null and a non nullable value.")
- end
-
- if n_expr.stype isa MMTypeNone then
- try_to_isa(v, n_expr2)
- else if n_expr2.stype isa MMTypeNone then
- try_to_isa(v, n_expr)
- end
- end
-
- private fun try_to_isa(v: TypingVisitor, n: AExpr)
- do
- var variable = n.its_variable
- if variable != null then
- _if_true_variable_ctx = v.variable_ctx.sub_with(self, variable, n.stype.as_notnull)
- end
- end
-end
-redef class ALtExpr
- redef fun name do return once "<".to_symbol
-end
-redef class ALeExpr
- redef fun name do return once "<=".to_symbol
-end
-redef class AGtExpr
- redef fun name do return once ">".to_symbol
-end
-redef class AGeExpr
- redef fun name do return once ">=".to_symbol
-end
-redef class APlusExpr
- redef fun name do return once "+".to_symbol
-end
-redef class AMinusExpr
- redef fun name do return once "-".to_symbol
-end
-redef class AStarshipExpr
- redef fun name do return once "<=>".to_symbol
-end
-redef class AStarExpr
- redef fun name do return once "*".to_symbol
-end
-redef class ASlashExpr
- redef fun name do return once "/".to_symbol
-end
-redef class APercentExpr
- redef fun name do return once "%".to_symbol
-end
-
-redef class AUminusExpr
- redef fun name do return once "unary -".to_symbol
- redef fun compute_raw_arguments do return null
-end
-
-redef class ACallFormExpr
- redef fun after_typing(v)
- do
- if n_expr.is_implicit_self then
- var name = n_id.to_symbol
- var variable = v.variable_ctx[name]
- if variable != null then
- var n: AExpr
- if variable isa ClosureVariable then
- n = new AClosureCallExpr.init_aclosurecallexpr(n_id, n_args, n_closure_defs)
- n._variable = variable
- else
- if not n_args.is_empty then
- v.error(self, "Error: {name} is variable, not a function.")
- return
- end
- n = variable_create(variable)
- n._variable = variable
- end
- replace_with(n)
- n.after_typing(v)
- return
- end
- end
-
- super
- end
-
- redef fun closure_defs
- do
- if n_closure_defs.is_empty then
- return null
- else
- return n_closure_defs.to_a
- end
- end
-
- # Create a variable acces corresponding to the call form
- fun variable_create(variable: Variable): AVarFormExpr is abstract
-end
-
-redef class ACallExpr
- redef fun variable_create(variable)
- do
- return new AVarExpr.init_avarexpr(n_id)
- end
-
- redef fun name do return n_id.to_symbol
- redef fun compute_raw_arguments do return n_args.to_a
-end
-
-redef class ACallAssignExpr
- redef fun variable_create(variable)
- do
- return new AVarAssignExpr.init_avarassignexpr(n_id, n_assign, n_value)
- end
-
- redef fun name do return (n_id.text + "=").to_symbol
- redef fun compute_raw_arguments do
- var res = n_args.to_a
- res.add(n_value)
- return res
- end
-end
-
-redef class ACallReassignExpr
- redef fun variable_create(variable)
- do
- return new AVarReassignExpr.init_avarreassignexpr(n_id, n_assign_op, n_value)
- end
-
- redef fun name do return n_id.to_symbol
- redef fun compute_raw_arguments do return n_args.to_a
-end
-
-redef class ABraExpr
- redef fun name do return once "[]".to_symbol
- redef fun compute_raw_arguments do return n_args.to_a
- redef fun closure_defs
- do
- if n_closure_defs.is_empty then
- return null
- else
- return n_closure_defs.to_a
- end
- end
-end
-
-redef class ABraAssignExpr
- redef fun name do return once "[]=".to_symbol
- redef fun compute_raw_arguments do
- var res = n_args.to_a
- res.add(n_value)
- return res
- end
-end
-
-redef class ABraReassignExpr
- redef fun name do return once "[]".to_symbol
- redef fun compute_raw_arguments do return n_args.to_a
-end
-
-redef class AInitExpr
- redef fun name do return once "init".to_symbol
- redef fun compute_raw_arguments do return n_args.to_a
-end
-
-redef class AClosureCallExpr
- var _variable: nullable ClosureVariable
- redef fun variable do return _variable.as(not null)
- redef fun compute_raw_arguments do return n_args.to_a
-
- redef fun after_typing(v)
- do
- var va = variable
- if va.closure.is_break then v.variable_ctx.unreash = true
- var sig = va.closure.signature
- var s = process_signature(v, sig, n_id.to_symbol, compute_raw_arguments)
- if not n_closure_defs.is_empty then
- process_closures(v, sig, n_id.to_symbol, n_closure_defs.to_a)
- end
- if not s then return
- _prop_signature = sig
- _stype = sig.return_type
- _is_typed = true
- end
-end
-
-redef class AClosureId
- fun to_symbol: Symbol is abstract
-end
-redef class ASimpleClosureId
- redef fun to_symbol: Symbol do return n_id.to_symbol
-end
-redef class ABreakClosureId
- redef fun to_symbol: Symbol do return n_kwbreak.to_symbol
-end
-
-redef class AClosureDef
- var _closure: nullable MMClosure
- redef fun closure do return _closure.as(not null)
-
- # The corresponding escapable object
- readable var _escapable: nullable EscapableBlock
-
- var _accept_typing2: Bool = false
- redef fun accept_typing(v)
- do
- # Typing is deferred, wait accept_typing2(v)
- if _accept_typing2 then super
- end
-
- private fun accept_typing2(v: TypingVisitor, esc: EscapableClosure)
- do
- _escapable = esc
-
- var sig = esc.closure.signature
- if sig.arity != n_ids.length then
- v.error(self, "Error: {sig.arity} automatic variable names expected, {n_ids.length} found.")
- return
- end
-
- _closure = esc.closure
-
- var old_var_ctx = v.variable_ctx
- var old_base_var_ctx = v.base_variable_ctx
- v.base_variable_ctx = v.variable_ctx
- v.variable_ctx = v.variable_ctx.sub(self)
- variables = new Array[AutoVariable]
- for i in [0..n_ids.length[ do
- var va = new AutoVariable(n_ids[i].to_symbol, self)
- variables.add(va)
- va.stype = sig[i]
- v.variable_ctx.add(va)
- end
-
- _accept_typing2 = true
- accept_typing(v)
-
- if v.variable_ctx.unreash == false then
- if closure.signature.return_type != null then
- v.error(self, "Control error: Reached end of block (a 'continue' with a value was expected).")
- else if closure.is_break then
- v.error(self, "Control error: Reached end of break block (a 'break' was expected).")
- end
- end
- v.variable_ctx = old_var_ctx
- v.base_variable_ctx = old_base_var_ctx
- end
-end
-
-class ATypeCheckExpr
-special AExpr
- private fun check_expr_cast(v: TypingVisitor, n_expr: AExpr, n_type: AType)
- do
- if not v.check_expr(n_expr) then return
- if not n_type.is_typed then return
- var etype = n_expr.stype
- var ttype = n_type.stype
- if etype == ttype then
- v.warning(self, "Warning: Expression is already a {ttype}.")
- else if etype < ttype then
- v.warning(self, "Warning: Expression is already a {ttype} since it is a {etype}.")
- else if etype.is_nullable and etype.as_notnull == ttype then
- if ttype isa MMTypeFormal and ttype.bound.is_nullable then
- # No warning in this case since with
- # type T: nullable A
- # var x: nullable T
- # 'x.as(not null)' != 'x.as(T)'
- # 'x != null' != 'x isa T'
- else if self isa AIsaExpr then
- v.warning(self, "Warning: Prefer '!= null'.")
- else
- v.warning(self, "Warning: Prefer '.as(not null)'.")
- end
- end
- end
-end
-
-redef class AIsaExpr
-special ATypeCheckExpr
- redef fun after_typing(v)
- do
- check_expr_cast(v, n_expr, n_type)
- if not n_type.is_typed then return
- var variable = n_expr.its_variable
- if variable != null then
- _if_true_variable_ctx = v.variable_ctx.sub_with(self, variable, n_type.stype)
- end
- _stype = v.type_bool
- _is_typed = true
- end
-end
-
-redef class AAsCastExpr
-special ATypeCheckExpr
- redef fun after_typing(v)
- do
- check_expr_cast(v, n_expr, n_type)
- if not n_type.is_typed then return
- _stype = n_type.stype
- _is_typed = _stype != null
- end
-end
-
-redef class AAsNotnullExpr
- redef fun after_typing(v)
- do
- if not v.check_expr(n_expr) then return
- var t = n_expr.stype
- if t isa MMTypeNone then
- v.error(n_expr, "Type error: 'as(not null)' on 'null' value.")
- return
- else if not t.is_nullable then
- v.warning(n_expr, "Warning: 'as(not null)' on non nullable type.")
- end
- _stype = n_expr.stype.as_notnull
- _is_typed = true
- end
-end
-
-redef class AProxyExpr
- redef fun after_typing(v)
- do
- if not n_expr.is_typed then return
- _is_typed = true
- if n_expr.is_statement then return
- _stype = n_expr.stype
- end
-end
-
-redef class AOnceExpr
- redef fun accept_typing(v)
- do
- if v.once_count > 0 then
- v.warning(self, "Useless once in a once expression.")
- end
- v.once_count = v.once_count + 1
-
- super
-
- v.once_count = v.once_count - 1
- end
-end
-