Cleaner, simpler elif.

interpreter.py

@@ -1209,32 +1209,13 @@ class Interpreter():
                 self.evaluate_codeblock(node.trueblock)
             else:
                 block = node.falseblock
-                if isinstance(block, nodes.ElifStatement):
-                    self.evaluate_elif(block)
+                if isinstance(block, nodes.IfStatement):
+                    self.evaluate_if(block)
                 else:
                     self.evaluate_codeblock(block)
         else:
             raise InvalidCode('If clause does not evaluate to true or false.')
 
-    def evaluate_elif(self, node):
-        result = self.evaluate_statement(node.clause)
-        cond = None
-        if isinstance(result, nodes.BoolExpression) or \
-           isinstance(result, nodes.BoolStatement):
-            cond = result.get_value()
-        if isinstance(result, bool):
-            cond = result
-        if cond is not None:
-            if cond:
-                self.evaluate_codeblock(node.trueblock)
-            else:
-                block = node.elseblock
-                if isinstance(block, nodes.ElifStatement):
-                    self.evaluate_elif(block)
-                self.evaluate_codeblock(block)
-        else:
-            raise InvalidCode('Elif clause does not evaluate to true or false.')
-
     def is_elementary_type(self, v):
         if isinstance(v, int) or isinstance(v, str) or isinstance(v, bool):
             return True

mparser.py

@@ -208,7 +208,7 @@ def p_statement_not(t):
 
 def p_statement_elif(t):
     'elseblock : ELIF statement EOL codeblock elseblock'
-    t[0] = nodes.ElifStatement(t[2], t[4], t[5], t.lineno(1))
+    t[0] = nodes.IfStatement(t[2], t[4], t[5], t.lineno(1))
 
 def p_empty_else(t):
     'elseblock : '

nodes.py

@@ -106,13 +106,6 @@ class IfStatement(Statement):
         self.trueblock = trueblock
         self.falseblock = falseblock
 
-class ElifStatement(Statement):
-    def __init__(self, clause, trueblock, elseblock, lineno):
-        Statement.__init__(self, lineno)
-        self.clause = clause
-        self.trueblock = trueblock
-        self.elseblock = elseblock
-
     def get_clause(self):
         return self.clause
 

test cases/common/41 elif/meson.build

@@ -0,0 +1,28 @@
+project('elseif', 'c')
+
+t = true
+f = false
+
+if true
+  message('Ok.')
+elif true
+  error('Error')
+else
+  error('Error')
+endif
+
+if f
+  error('Error.')
+elif t
+  message('Ok')
+else
+  error('Error')
+endif
+
+if f
+  error('Error.')
+elif false
+  error('Error')
+else
+  message('Ok')
+endif