src: new module parser_util.nit

Signed-off-by: Jean Privat <jean@pryen.org>

diff --git a/src/parser_util.nit b/src/parser_util.nit
new file mode 100644 (file)
index 0000000..f9ea467
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+++ b/src/parser_util.nit
@@ -0,0 +1,108 @@
+# This file is part of NIT ( http://www.nitlanguage.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.
+
+# Utils and tools related to parsers and AST
+module parser_util
+
+import parser
+import toolcontext
+
+redef class ToolContext
+       # Parse a full module given as a string
+       # Fatal error if the `string` is not a syntactically correct module
+       fun parse_module(string: String): AModule
+       do
+               var source = new SourceFile.from_string("", string)
+               var lexer = new Lexer(source)
+               var parser = new Parser(lexer)
+               var tree = parser.parse
+
+               var eof = tree.n_eof
+               if eof isa AError then
+                       self.fatal_error(null, "Fatal Error: {eof.message}")
+                       abort
+               end
+               return tree.n_base.as(not null)
+       end
+
+       # Parse a full classdef given as a string
+       # Fatal error if the `string` is not a syntactically correct class definition
+       fun parse_classdef(string: String): AClassdef
+       do
+               var nmodule = parse_module(string)
+               var nclassdefs = nmodule.n_classdefs
+               if nclassdefs.length != 1 then
+                       self.fatal_error(null, "Fatal Error: not a classdef")
+                       abort
+               end
+               return nclassdefs.first
+       end
+
+       # Parse a full propdef given as a string
+       # Fatal error if the `string` is not a syntactically correct property definition
+       fun parse_propdef(string: String): APropdef
+       do
+               var mod_string = "class Dummy\n{string}\nend"
+               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")
+                       abort
+               end
+               return npropdefs.first
+       end
+
+       # Parse a full statement block given as a string
+       # Fatal error if the `string` is not a syntactically correct statement block
+       fun parse_stmts(string: String): AExpr
+       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)
+               return nblock
+       end
+
+       # Parse a full expression given as a string
+       # Fatal error if the `string` is not a syntactically correct expression
+       fun parse_expr(string: String): AExpr
+       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)
+               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]
+       do
+               var v = new CollectTokensByTextVisitor(text)
+               v.enter_visit(self)
+               return v.result
+       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)
+       do
+               if node == null then return
+               node.visit_all(self)
+               if node isa Token and node.text == text then result.add(node)
+       end
+end