Mercurial Repositories > eric / file diff

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/eric6/Plugins/CheckerPlugins/CodeStyleChecker/AstUtilities.py	Fri Oct 04 17:31:14 2019 +0200
@@ -0,0 +1,191 @@
+# -*- coding: utf-8 -*-
+
+# Copyright (c) 2019 Detlev Offenbach <detlev@die-offenbachs.de>
+#
+
+"""
+Module implementing some utility and compatibility functions for working with
+the ast module.
+"""
+
+import sys
+import ast
+
+if sys.version_info >= (3, 8, 0):
+    # functions for Python >= 3.8
+    
+    import numbers
+    
+    def isNumber(node):
+        """
+        Function to check that a node is a number.
+        
+        @param node reference to the node to check
+        @type ast.AST
+        @return flag indicating a number
+        @rtype bool
+        """
+        return (
+            isinstance(node, ast.Constant) and
+            isinstance(node.value, numbers.Number)
+        )
+    
+    def isString(node):
+        """
+        Function to check that a node is a string.
+        
+        @param node reference to the node to check
+        @type ast.AST
+        @return flag indicating a string
+        @rtype bool
+        """
+        return (
+            isinstance(node, ast.Constant) and
+            isinstance(node.value, str)
+        )
+    
+    def isBytes(node):
+        """
+        Function to check that a node is a bytes.
+        
+        @param node reference to the node to check
+        @type ast.AST
+        @return flag indicating a bytes
+        @rtype bool
+        """
+        return (
+            isinstance(node, ast.Constant) and
+            isinstance(node.value, bytes)
+        )
+    
+    def isBaseString(node):
+        """
+        Function to check that a node is a bytes or string.
+        
+        @param node reference to the node to check
+        @type ast.AST
+        @return flag indicating a bytes or string
+        @rtype bool
+        """
+        return (
+            isinstance(node, ast.Constant) and
+            isinstance(node.value, (bytes, str))
+        )
+    
+    def isNameConstant(node):
+        """
+        Function to check that a node is a name constant.
+        
+        @param node reference to the node to check
+        @type ast.AST
+        @return flag indicating a name constant
+        @rtype bool
+        """
+        return (
+            isinstance(node, ast.Constant) and
+            not isinstance(node.value, (bytes, str, numbers.Number))
+        )
+    
+    def getValue(node):
+        """
+        Function to extract the value of a node.
+        
+        @param node reference to the node to extract the value from
+        @type ast.Constant
+        @return value of the node
+        @rtype any
+        @exception TypeError raised to indicate an unsupported type
+        """
+        if isinstance(node, ast.Constant):
+            return node.value
+        else:
+            raise TypeError("Illegal node type passed.")
+
+else:
+    # functions for Python < 3.8
+    
+    def isNumber(node):
+        """
+        Function to check that a node is a number.
+        
+        @param node reference to the node to check
+        @type ast.AST
+        @return flag indicating a number
+        @rtype bool
+        """
+        return isinstance(node, ast.Num)
+    
+    def isString(node):
+        """
+        Function to check that a node is a string.
+        
+        @param node reference to the node to check
+        @type ast.AST
+        @return flag indicating a string
+        @rtype bool
+        """
+        return isinstance(node, ast.Str)
+    
+    def isBytes(node):
+        """
+        Function to check that a node is a bytes.
+        
+        @param node reference to the node to check
+        @type ast.AST
+        @return flag indicating a bytes
+        @rtype bool
+        """
+        return (
+            sys.version_info[0] >= 3 and
+            isinstance(node, ast.Bytes)
+        )
+    
+    def isBaseString(node):
+        """
+        Function to check that a node is a bytes or string.
+        
+        @param node reference to the node to check
+        @type ast.AST
+        @return flag indicating a bytes or string
+        @rtype bool
+        """
+        typ = (ast.Str,)
+        if sys.version_info[0] > 2:
+            typ += (ast.Bytes,)
+        return isinstance(node, typ)
+    
+    def isNameConstant(node):
+        """
+        Function to check that a node is a name constant.
+        
+        @param node reference to the node to check
+        @type ast.AST
+        @return flag indicating a name constant
+        @rtype bool
+        """
+        return isinstance(node, ast.NameConstant)
+    
+    def getValue(node):
+        """
+        Function to extract the value of a node.
+        
+        @param node reference to the node to extract the value from
+        @type one of ast.Num, ast.Str, ast.Bytes or ast.NameConstant
+        @return value of the node
+        @rtype one of str, bytes, int
+        @exception TypeError raised to indicate an unsupported type
+        """
+        if isinstance(node, ast.Num):
+            return node.n
+        
+        elif isinstance(node, ast.Str):
+            return node.s
+        
+        elif sys.version_info[0] > 2 and isinstance(node, ast.Bytes):
+            return node.s
+        
+        elif isinstance(node, ast.NameConstant):
+            return node.value
+        
+        else:
+            raise TypeError("Illegal node type passed.")