1 # This file is part of NIT ( http://www.nitlanguage.org ).
3 # Copyright 2012 Jean Privat <jean@pryen.org>
5 # Licensed under the Apache License, Version 2.0 (the "License");
6 # you may not use this file except in compliance with the License.
7 # You may obtain a copy of the License at
9 # http://www.apache.org/licenses/LICENSE-2.0
11 # Unless required by applicable law or agreed to in writing, software
12 # distributed under the License is distributed on an "AS IS" BASIS,
13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 # See the License for the specific language governing permissions and
15 # limitations under the License.
17 # Parsing of literal values in the abstract syntax tree.
22 redef class ToolContext
23 # Parses literal values in the whole AST and produces errors if needed
24 var literal_phase
: Phase = new LiteralPhase(self, null)
27 private class LiteralPhase
30 redef fun process_nmodule
(nmodule
) do nmodule
.do_literal
(toolcontext
)
34 # Visit the module to compute the real value of the literal-related node of the AST.
35 # Warnings and errors are displayed on the toolcontext.
36 fun do_literal
(toolcontext
: ToolContext)
38 var v
= new LiteralVisitor(toolcontext
)
43 private class LiteralVisitor
46 var toolcontext
: ToolContext
50 n
.accept_literal
(self)
56 private fun accept_literal
(v
: LiteralVisitor) do end
60 # Get `self` as a `String`.
61 # Return null if not a string.
62 fun as_string
: nullable String
64 if not self isa AStringFormExpr then return null
65 return self.value
.as(not null)
68 # Get `self` as an `Int`.
69 # Return null if not an integer.
70 fun as_int
: nullable Int
72 if not self isa AIntExpr then return null
73 return self.value
.as(not null)
76 # Get `self` as a single identifier.
77 # Return null if not a single identifier.
78 fun as_id
: nullable String
80 if self isa AMethidExpr then
81 return self.collect_text
83 if not self isa ACallExpr then return null
84 if not self.n_expr
isa AImplicitSelfExpr then return null
85 if not self.n_args
.n_exprs
.is_empty
then return null
92 # The value of the literal int once computed.
93 var value
: nullable Int
96 redef class ADecIntExpr
97 redef fun accept_literal
(v
)
99 self.value
= self.n_number
.text
.to_i
103 redef class AHexIntExpr
104 redef fun accept_literal
(v
)
106 self.value
= self.n_hex_number
.text
.substring_from
(2).to_hex
110 redef class AFloatExpr
111 # The value of the literal float once computed.
112 var value
: nullable Float
113 redef fun accept_literal
(v
)
115 self.value
= self.n_float
.text
.to_f
119 redef class ACharExpr
120 # The value of the literal char once computed.
121 var value
: nullable Char
122 redef fun accept_literal
(v
)
124 var txt
= self.n_char
.text
.unescape_nit
125 if txt
.length
!= 3 then
126 v
.toolcontext
.error
(self.hot_location
, "Invalid character literal {txt}")
129 self.value
= txt
.chars
[1]
133 redef class AStringFormExpr
134 # The value of the literal string once computed.
135 var value
: nullable String
136 redef fun accept_literal
(v
)
138 var txt
= self.n_string
.text
141 if txt
.chars
[0] == txt
.chars
[1] and txt
.length
>= 6 then
144 if txt
.chars
[0] == '"' and txt
.chars
[3] == '\n' then behead
= 4 # ignore first \n in """
146 self.value
= txt
.substring
(behead
, txt
.length
- behead
- betail
).unescape_nit