# Utils and tools related to parsers and AST
module parser_util
-import parser
+intrude import parser
import toolcontext
redef class ToolContext
var eof = tree.n_eof
if eof isa AError then
- self.fatal_error(null, "Fatal Error: {eof.message}")
+ self.fatal_error(null, "Fatal Error: {eof.message}.")
abort
end
return tree.n_base.as(not null)
var nmodule = parse_module(string)
var nclassdefs = nmodule.n_classdefs
if nclassdefs.length != 1 then
- self.fatal_error(null, "Fatal Error: not a classdef")
+ self.fatal_error(null, "Fatal Error: not a classdef.")
abort
end
return nclassdefs.first
var nclassdef = parse_classdef(mod_string)
var npropdefs = nclassdef.n_propdefs
if npropdefs.length != 1 then
- self.fatal_error(null, "Fatal Error: not a propdef")
+ self.fatal_error(null, "Fatal Error: not a propdef.")
abort
end
return npropdefs.first
do
var mod_string = "do\n{string}\nend"
var nmodule = parse_module(mod_string)
- var nblock = nmodule.n_classdefs.first.n_propdefs.first.as(AMainMethPropdef).n_block.as(ABlockExpr).n_expr.first.as(ADoExpr).n_block.as(not null)
+ var nblock = nmodule.n_classdefs.first.n_propdefs.first.as(AMethPropdef).n_block.as(ABlockExpr).n_expr.first.as(ADoExpr).n_block.as(not null)
return nblock
end
do
var mod_string = "var dummy = \n{string}"
var nmodule = parse_module(mod_string)
- var nexpr = nmodule.n_classdefs.first.n_propdefs.first.as(AMainMethPropdef).n_block.as(ABlockExpr).n_expr.first.as(AVardeclExpr).n_expr.as(not null)
+ var nexpr = nmodule.n_classdefs.first.n_propdefs.first.as(AMethPropdef).n_block.as(ABlockExpr).n_expr.first.as(AVardeclExpr).n_expr.as(not null)
return nexpr
end
-end
-redef class ANode
- # Return an array of tokens that match a given text
- fun collect_tokens_by_text(text: String): Array[Token]
+ # Parse a super class declaration
+ # Fatal error if the `string` is not a syntactically correct super class declaration
+ fun parse_superclass(string: String): APropdef
+ do
+ var mod_string = "class Dummy\nsuper {string}\nend"
+ var nclassdef = parse_classdef(mod_string).as(AStdClassdef)
+ var nsuperclasses = nclassdef.n_propdefs
+ if nsuperclasses.length != 1 then
+ self.fatal_error(null, "Fatal Error: not a super class declaration.")
+ abort
+ end
+ return nsuperclasses.first
+ end
+
+ # Try to parse the `string` as something
+ #
+ # Returns the first possible syntacticaly correct type among:
+ #
+ # - a type `AType`
+ # - a single `Token`
+ # - an expression `AExpr`
+ # - a block of statements `ABlockExpr`
+ # - a full module `AModule`
+ # - a `AError` if nothing else matches
+ #
+ # var tc = new ToolContext
+ # assert tc.parse_something("foo") isa TId
+ # assert tc.parse_something("foo[bar]") isa AExpr
+ # assert tc.parse_something("Foo[Bar]") isa AType
+ # assert tc.parse_something("foo\nbar") isa ABlockExpr
+ # assert tc.parse_something("fun foo do bar\nfoo") isa AModule
+ # assert tc.parse_something("fun fun") isa AParserError
+ # assert tc.parse_something("?%^&") isa ALexerError
+ fun parse_something(string: String): ANode
+ do
+ var source = new SourceFile.from_string("", string)
+ var error
+ var tree
+ var eof
+ var lexer
+
+ lexer = new InjectedLexer(source)
+ lexer.injected_before.add new TKwvar
+ lexer.injected_before.add new TId
+ lexer.injected_before.add new TColumn
+ lexer.injected_before.add new TClassid
+ lexer.injected_before.add new TObra
+ lexer.injected_after.add new TCbra
+ tree = (new Parser(lexer)).parse
+ eof = tree.n_eof
+ if not eof isa AError then
+ var ntype = tree.n_base.n_classdefs.first.n_propdefs.first.as(AMethPropdef).n_block.as(ABlockExpr).n_expr.first.as(AVardeclExpr).n_type.n_types.first
+ ntype.parent = null
+ return ntype
+ end
+ error = eof
+
+ lexer = new Lexer(source)
+ var first = lexer.next
+ if first isa EOF then return first
+ var second = lexer.next
+ if second isa EOF and not second isa AError then
+ first.parent = null
+ return first
+ end
+
+ lexer = new InjectedLexer(source)
+ lexer.injected_before.add new TKwvar
+ lexer.injected_before.add new TId
+ lexer.injected_before.add new TAssign
+ lexer.injected_before.add new TOpar
+ lexer.injected_after.add new TCpar
+ tree = (new Parser(lexer)).parse
+ eof = tree.n_eof
+ if not eof isa AError then
+ var nexpr = tree.n_base.n_classdefs.first.n_propdefs.first.as(AMethPropdef).n_block.as(ABlockExpr).n_expr.first.as(AVardeclExpr).n_expr.as(AParExpr).n_expr
+ nexpr.parent = null
+ return nexpr
+ end
+ if eof.location > error.location then error = eof
+
+ lexer = new InjectedLexer(source)
+ lexer.injected_before.add new TKwdo
+ lexer.injected_before.add new TEol
+ lexer.injected_after.add new TEol
+ lexer.injected_after.add new TKwend
+ tree = (new Parser(lexer)).parse
+ eof = tree.n_eof
+ if not eof isa AError then
+ var nblock = tree.n_base.n_classdefs.first.n_propdefs.first.as(AMethPropdef).n_block.as(ABlockExpr).n_expr.first.as(ADoExpr).n_block.as(ABlockExpr)
+ nblock.n_kwend = null # drop injected token
+ nblock.parent = null
+ return nblock
+ end
+ if eof.location > error.location then error = eof
+
+ lexer = new Lexer(source)
+ tree = (new Parser(lexer)).parse
+ eof = tree.n_eof
+ if not eof isa AError then
+ return tree.n_base.as(not null)
+ end
+ if eof.location > error.location then error = eof
+
+ return error
+ end
+
+ # Parse the input of the user as something
+ fun interactive_parse(prompt: String): ANode
do
- var v = new CollectTokensByTextVisitor(text)
- v.enter_visit(self)
- return v.result
+ var oldtext = ""
+
+ loop
+ printn prompt
+ printn " "
+ var s = sys.stdin.read_line
+ if s == "" then continue
+ if s.chars.first == ':' then
+ var res = new TString
+ res.text = s
+ return res
+ end
+
+ var text = oldtext + s + "\n"
+ oldtext = ""
+ var n = parse_something(text)
+
+ if n isa AParserError and n.token isa EOF then
+ # Unexpected end of file, thus continuing
+ if oldtext == "" then prompt = "." * prompt.length
+ oldtext = text
+ continue
+ end
+
+ return n
+ end
end
end
-private class CollectTokensByTextVisitor
- super Visitor
- var text: String
- init(text: String) do self.text = text
- var result = new Array[Token]
- redef fun visit(node)
+# A modified lexer that feed tokens before and after the real tokens.
+class InjectedLexer
+ super Lexer
+
+ # The tokens to use before the real tokens (in order).
+ var injected_before = new List[Token]
+
+ # The tokens to use after the real tokens (in order).
+ # The real EOF token is produced after these tokens.
+ var injected_after = new List[Token]
+ private var is_finished = false
+
+ redef fun get_token
do
- if node == null then return
- node.visit_all(self)
- if node isa Token and node.text == text then result.add(node)
+ if not injected_before.is_empty then
+ var tok = injected_before.shift
+ return tok
+ end
+ if not is_finished then
+ var next = super
+ if not next isa EOF then return next
+ injected_after.push(next)
+ is_finished = true
+ end
+
+ var tok = injected_after.shift
+ return tok
end
end
nitlanguage / nit.git / blobdiff