Implement a foreach loop construct. Closes #17.

interpreter.py

@@ -807,6 +807,8 @@ class Interpreter():
             return self.evaluate_orstatement(cur)
         elif isinstance(cur, mparser.NotNode):
             return self.evaluate_notstatement(cur)
+        elif isinstance(cur, mparser.ForeachClauseNode):
+            return self.evaluate_foreach(cur)
         else:
             raise InvalidCode("Unknown statement.")
 
@@ -1486,6 +1488,13 @@ class Interpreter():
     def array_method_call(self, obj, method_name, args):
         if method_name == 'contains':
             return self.check_contains(obj, args)
+        elif method_name == 'get':
+            index = args[0]
+            if not isinstance(index, int):
+                raise InvalidArguments('Array index must be a number.')
+            if index < 0 or index >= len(obj):
+                raise InvalidArguments('Array index %s is out of bounds for array of size %d.' % (index, len(obj)))
+            return obj[index]
         raise InterpreterException('Arrays do not have a method called "%s".' % method_name)
 
     def check_contains(self, obj, args):
@@ -1517,6 +1526,16 @@ class Interpreter():
         if not isinstance(node.elseblock, mparser.EmptyNode):
             self.evaluate_codeblock(node.elseblock)
 
+    def evaluate_foreach(self, node):
+        assert(isinstance(node, mparser.ForeachClauseNode))
+        varname = node.varname.value
+        items = self.evaluate_statement(node.items)
+        if not isinstance(items, list):
+            raise InvalidArguments('Items of foreach loop is not an array')
+        for item in items:
+            self.set_variable(varname, item)
+            self.evaluate_codeblock(node.block)
+
     def is_elementary_type(self, v):
         if isinstance(v, int) or isinstance(v, str) or isinstance(v, bool):
             return True

mparser.py

@@ -17,6 +17,8 @@
 import re
 import sys
 from coredata import MesonException
+from array import array
+from orca.messages import itemsFound
 
 class ParseException(MesonException):
     def __init__(self, text, lineno, colno):
@@ -39,7 +41,7 @@ class Token:
 class Lexer:
     def __init__(self):
         self.keywords = {'true', 'false', 'if', 'else', 'elif',
-                         'endif', 'and', 'or', 'not'}
+                         'endif', 'and', 'or', 'not', 'foreach', 'endforeach'}
         self.token_specification = [
             # Need to be sorted longest to shortest.
             ('ignore', re.compile(r'[ \t]')),
@@ -214,6 +216,14 @@ class AssignmentNode:
         assert(isinstance(var_name, str))
         self.value = value
 
+class ForeachClauseNode():
+    def __init__(self, lineno, colno, varname, items, block):
+        self.lineno = lineno
+        self.colno = colno
+        self.varname = varname
+        self.items = items
+        self.block = block
+
 class IfClauseNode():
     def __init__(self, lineno, colno):
         self.lineno = lineno
@@ -417,6 +427,15 @@ class Parser:
             return self.method_call(method)
         return method
 
+    def foreachblock(self):
+        t = self.current
+        self.expect('id')
+        varname = t
+        self.expect('colon')
+        items = self.statement()
+        block = self.codeblock()
+        return ForeachClauseNode(varname.lineno, varname.colno, varname, items, block)
+
     def ifblock(self):
         condition = self.statement()
         clause = IfClauseNode(condition.lineno, condition.colno)
@@ -445,6 +464,10 @@ class Parser:
             block = self.ifblock()
             self.expect('endif')
             return block
+        if self.accept('foreach'):
+            block = self.foreachblock()
+            self.expect('endforeach')
+            return block
         return self.statement()
 
     def codeblock(self):

test cases/common/67 foreach/installed_files.txt

@@ -0,0 +1,3 @@
+bin/prog1
+bin/prog2
+bin/prog3

test cases/common/67 foreach/meson.build

@@ -0,0 +1,16 @@
+project('foreach', 'c')
+
+tests = [['test1', 'prog1', 'prog1.c'],
+  ['test2', 'prog2', 'prog2.c'],
+  ['test3', 'prog3', 'prog3.c']]
+
+foreach i : tests
+  test(i.get(0), executable(i.get(1), i.get(2), install : true))
+
+  # Ensure that changing the tests variable does not
+  # affect ongoing iteration in the foreach loop.
+  #
+  # Being able to do that would make Meson Turing complete and
+  # we definitely don't want that.
+  tests = ['test4', 'prog4', 'prog4.c']
+endforeach

test cases/common/67 foreach/prog1.c

@@ -0,0 +1,6 @@
+#include<stdio.h>
+
+int main(int argc, char **argv) {
+    printf("This is test #1.\n");
+    return 0;
+}

test cases/common/67 foreach/prog2.c

@@ -0,0 +1,6 @@
+#include<stdio.h>
+
+int main(int argc, char **argv) {
+    printf("This is test #2.\n");
+    return 0;
+}

test cases/common/67 foreach/prog3.c

@@ -0,0 +1,6 @@
+#include<stdio.h>
+
+int main(int argc, char **argv) {
+    printf("This is test #3.\n");
+    return 0;
+}

test cases/failing/10 out of bounds/meson.build

@@ -0,0 +1,4 @@
+project('out of bounds', 'c')
+
+x = []
+y = x.get(0)