# Parsing of literal values in the abstract syntax tree.
module literal
-import parser
-import toolcontext
import phase
-import modelbuilder #FIXME useless
-
redef class ToolContext
+ # Parses literal values in the whole AST and produces errors if needed
var literal_phase: Phase = new LiteralPhase(self, null)
end
var toolcontext: ToolContext
- init(toolcontext: ToolContext)
- do
- self.toolcontext = toolcontext
- end
-
redef fun visit(n)
do
n.accept_literal(self)
private fun accept_literal(v: LiteralVisitor) do end
end
+redef class AExpr
+ # Get `self` as a `String`.
+ # Return null if not a string.
+ fun as_string: nullable String
+ do
+ if not self isa AStringFormExpr then return null
+ return self.value.as(not null)
+ end
+
+ # Get `self` as an `Int`.
+ # Return null if not an integer.
+ fun as_int: nullable Int
+ do
+ if not self isa AIntExpr then return null
+ return self.value.as(not null)
+ end
+
+ # Get `self` as a single identifier.
+ # Return null if not a single identifier.
+ fun as_id: nullable String
+ do
+ if self isa AMethidExpr then
+ return self.collect_text
+ end
+ if not self isa ACallExpr then return null
+ if not self.n_expr isa AImplicitSelfExpr then return null
+ if not self.n_args.n_exprs.is_empty then return null
+ return self.n_id.text
+ end
+end
+
+
redef class AIntExpr
# The value of the literal int once computed.
var value: nullable Int
+end
+
+redef class ADecIntExpr
redef fun accept_literal(v)
do
self.value = self.n_number.text.to_i
end
end
+redef class AHexIntExpr
+ redef fun accept_literal(v)
+ do
+ self.value = self.n_hex_number.text.substring_from(2).to_hex
+ end
+end
+
redef class AFloatExpr
# The value of the literal float once computed.
var value: nullable Float
do
var txt = self.n_char.text.unescape_nit
if txt.length != 3 then
- v.toolcontext.error(self.hot_location, "Invalid character literal {txt}")
+ v.toolcontext.error(self.hot_location, "Syntax Error: invalid character literal `{txt}`.")
return
end
- self.value = txt[1]
+ self.value = txt.chars[1]
end
end
redef fun accept_literal(v)
do
var txt = self.n_string.text
- var skip = 1
- if txt[0] == txt[1] and txt.length >= 6 then skip = 3
- self.value = txt.substring(skip, txt.length-(2*skip)).unescape_nit
- end
-end
-
-redef class String
- # Return a string where Nit escape sequences are transformed.
- #
- # Example:
- # var s = "\\n"
- # print s.length # -> 2
- # var u = s.unescape_nit
- # print s.length # -> 1
- # print s[0].ascii # -> 10 (the ASCII value of the "new line" character)
- fun unescape_nit: String
- do
- var res = new Buffer.with_capacity(self.length)
- var was_slash = false
- for c in self do
- if not was_slash then
- if c == '\\' then
- was_slash = true
- else
- res.add(c)
- end
- continue
- end
- was_slash = false
- if c == 'n' then
- res.add('\n')
- else if c == 'r' then
- res.add('\r')
- else if c == 't' then
- res.add('\t')
- else if c == '0' then
- res.add('\0')
- else
- res.add(c)
- end
+ var behead = 1
+ var betail = 1
+ if txt.chars[0] == txt.chars[1] and txt.length >= 6 then
+ behead = 3
+ betail = 3
+ if txt.chars[0] == '"' and txt.chars[3] == '\n' then behead = 4 # ignore first \n in """
end
- return res.to_s
+ self.value = txt.substring(behead, txt.length - behead - betail).unescape_nit
end
end