issue #98 type check for statements

include/ravi_ast.h

@@ -250,6 +250,10 @@ struct ast_node {
       struct ast_node_list *suffix_list;
     } suffixed_expr;
     struct {
+      /* Note that in Ravi the results from a function call must be type asserted during assignment to variables.
+       * This is not explicit in the AST but is required to ensure that function return values do not
+       * overwrite the type of the variables in an inconsistent way.
+       */
       struct var_type type;
       TString *method_name;            /* Optional method_name */
       struct ast_node_list *arg_list; /* Call arguments */

ravi-tests/ravi_test_ast.expected

@@ -1427,7 +1427,7 @@ function()
     function()
     --locals  i
       for
-        i --local symbol ? 
+        i --local symbol integer 
       =
         1
        ,
@@ -1442,9 +1442,9 @@ function()
              --[suffix list start]
                --[function call start] any
                 (
-                  --[suffixed expr start] any
-                   --[primary start] any
-                     i --local symbol ? 
+                  --[suffixed expr start] integer
+                   --[primary start] integer
+                     i --local symbol integer 
                    --[primary end]
                   --[suffixed expr end]
                 )
@@ -1585,3 +1585,83 @@ function()
 end
 
 --
+--[[for i=1,10 do print(i+1) end return
+]]
+function()
+--locals  i
+  for
+    i --local symbol integer 
+  =
+    1
+   ,
+    10
+  do
+     --[expression statement start]
+      --[expression list start]
+        --[suffixed expr start] any
+         --[primary start] any
+           print --global symbol ? 
+         --[primary end]
+         --[suffix list start]
+           --[function call start] any
+            (
+              --[binary expr start] integer
+               --[suffixed expr start] integer
+                --[primary start] integer
+                  i --local symbol integer 
+                --[primary end]
+               --[suffixed expr end]
+              +
+               1
+              --[binary expr end]
+            )
+           --[function call end]
+         --[suffix list end]
+        --[suffixed expr end]
+      --[expression list end]
+     --[expression statement end]
+  end
+  return
+end
+
+--
+--[[for i=1.0, 10.0 do print(i+4.2) end return
+]]
+function()
+--locals  i
+  for
+    i --local symbol number 
+  =
+    1.0000000000000000
+   ,
+    10.0000000000000000
+  do
+     --[expression statement start]
+      --[expression list start]
+        --[suffixed expr start] any
+         --[primary start] any
+           print --global symbol ? 
+         --[primary end]
+         --[suffix list start]
+           --[function call start] any
+            (
+              --[binary expr start] number
+               --[suffixed expr start] number
+                --[primary start] number
+                  i --local symbol number 
+                --[primary end]
+               --[suffixed expr end]
+              +
+               4.2000000000000002
+              --[binary expr end]
+            )
+           --[function call end]
+         --[suffix list end]
+        --[suffixed expr end]
+      --[expression list end]
+     --[expression statement end]
+  end
+  return
+end
+
+--

ravi-tests/ravi_test_ast.lua

@@ -78,4 +78,7 @@ dotest 'return @integer[] {}'
 dotest 'return @number[] {}'
 dotest 'return @closure function() end'
 dotest 'return @number 54.4'
-dotest 'return @User.Type a'
+dotest 'return @User.Type a'
+
+dotest 'for i=1,10 do print(i+1) end return'
+dotest 'for i=1.0, 10.0 do print(i+4.2) end return'

ravi-tests/ravi_test_ast2.expected

@@ -291,7 +291,7 @@ function()
       --[symbols]
         sum --local symbol ? 
       for
-        j --local symbol ? 
+        j --local symbol integer 
       =
         1
        ,
@@ -310,7 +310,7 @@ function()
           --[expression list end]
          --[expression statement end]
          for
-           k --local symbol ? 
+           k --local symbol integer 
          =
            1
           ,
@@ -332,21 +332,21 @@ function()
                  --[primary end]
                 --[suffixed expr end]
                +
-                --[binary expr start] any
+                --[binary expr start] number
                  1.0000000000000000
                 /
-                 --[suffixed expr start] any
-                  --[primary start] any
-                   --[binary expr start] any
-                    --[suffixed expr start] any
-                     --[primary start] any
-                       k --local symbol ? 
+                 --[suffixed expr start] integer
+                  --[primary start] integer
+                   --[binary expr start] integer
+                    --[suffixed expr start] integer
+                     --[primary start] integer
+                       k --local symbol integer 
                      --[primary end]
                     --[suffixed expr end]
                    *
-                    --[suffixed expr start] any
-                     --[primary start] any
-                       k --local symbol ? 
+                    --[suffixed expr start] integer
+                     --[primary start] integer
+                       k --local symbol integer 
                      --[primary end]
                     --[suffixed expr end]
                    --[binary expr end]

src/ravi_ast_typecheck.c

@@ -129,6 +129,9 @@ static void typecheck_binaryop(struct ast_node *function, struct ast_node *node)
     case OPR_MOD:
       if (e1->common_expr.type.type_code == RAVI_TNUMINT && e2->common_expr.type.type_code == RAVI_TNUMINT)
         set_typecode(node->binary_expr.type, RAVI_TNUMINT);
+      else if ((e1->common_expr.type.type_code == RAVI_TNUMINT && e2->common_expr.type.type_code == RAVI_TNUMFLT) ||
+               (e1->common_expr.type.type_code == RAVI_TNUMFLT && e2->common_expr.type.type_code == RAVI_TNUMINT))
+        set_typecode(node->binary_expr.type, RAVI_TNUMFLT);
       break;
     default:
       set_typecode(node->binary_expr.type, RAVI_TANY);
@@ -204,7 +207,7 @@ static void typecheck_var_assignment(struct var_type *var_type, struct var_type
   }
 
   // all other types must strictly match
-  if (!is_type_same(*var_type, *expr_type)) { // We should probably check type convertability here
+  if (!is_type_same(*var_type, *expr_type)) {  // We should probably check type convertability here
     fprintf(stderr, "Assignment to local symbol %s is not type compatible\n", var_name);
   }
 }
@@ -238,7 +241,6 @@ static void typecheck_local_statement(struct ast_node *function, struct ast_node
 }
 
 static void typecheck_expr_statement(struct ast_node *function, struct ast_node *node) {
-
   if (node->expression_stmt.var_expr_list)
     typecheck_ast_list(function, node->expression_stmt.var_expr_list);
   typecheck_ast_list(function, node->expression_stmt.expr_list);
@@ -257,7 +259,7 @@ static void typecheck_expr_statement(struct ast_node *function, struct ast_node
 
     struct var_type *var_type = &var->common_expr.type;
     struct var_type *expr_type = &expr->common_expr.type;
-    const char *var_name = ""; // FIXME how do we get this?
+    const char *var_name = "";  // FIXME how do we get this?
 
     typecheck_var_assignment(var_type, expr_type, var_name);
 
@@ -266,6 +268,46 @@ static void typecheck_expr_statement(struct ast_node *function, struct ast_node
   }
 }
 
+static void typecheck_for_statment(struct ast_node *function, struct ast_node *node) {
+  typecheck_ast_list(function, node->for_stmt.expr_list);
+  if (node->type != AST_FORNUM_STMT) {
+    typecheck_ast_list(function, node->for_stmt.for_statement_list);
+    return;
+  }
+  /* for num case, the index variable's type */
+  struct ast_node *expr;
+  ravitype_t index_type = RAVI_TNUMINT;
+  int match_count = 0; /* number of expression matching index type */
+  /* First expression decides between int / float types. We allow int or float in subsequent
+   * expressions ... TODO may need changing.
+   */
+  FOR_EACH_PTR(node->for_stmt.expr_list, expr) {
+    if (expr->common_expr.type.type_code == RAVI_TNUMFLT) {
+      if (index_type != RAVI_TNUMFLT) {
+        index_type = (match_count == 0) ? RAVI_TNUMFLT : RAVI_TANY;
+      }
+    }
+    else if (expr->common_expr.type.type_code != RAVI_TNUMINT) {
+      index_type = RAVI_TANY;
+    }
+    if (index_type == RAVI_TANY)
+      break;
+    match_count++;
+  }
+  END_FOR_EACH_PTR(expr);
+  if (index_type == RAVI_TNUMINT || index_type == RAVI_TNUMFLT) {
+    struct lua_symbol_list *symbols = node->for_stmt.symbols;
+    struct lua_symbol *sym;
+    /* actually there will be only index variable */
+    FOR_EACH_PTR(symbols, sym) {
+      if (sym->symbol_type == SYM_LOCAL) {
+        set_typecode(sym->value_type, index_type);
+      }
+    }
+    END_FOR_EACH_PTR(sym);
+  }
+  typecheck_ast_list(function, node->for_stmt.for_statement_list);
+}
 
 /* Type checker - WIP  */
 static void typecheck_ast_node(struct ast_node *function, struct ast_node *node) {
@@ -317,9 +359,11 @@ static void typecheck_ast_node(struct ast_node *function, struct ast_node *node)
       break;
     }
     case AST_FORIN_STMT: {
+      typecheck_for_statment(function, node);
       break;
     }
     case AST_FORNUM_STMT: {
+      typecheck_for_statment(function, node);
       break;
     }
     case AST_SUFFIXED_EXPR: {
@@ -331,10 +375,12 @@ static void typecheck_ast_node(struct ast_node *function, struct ast_node *node)
       }
       else {
       }
+      typecheck_ast_list(function, node->function_call_expr.arg_list);
       break;
     }
     case AST_SYMBOL_EXPR: {
-      /* type should have been set when symbol was created */
+      /* symbol type should have been set when symbol was created */
+      copy_type(node->symbol_expr.type, node->symbol_expr.var->value_type);
       break;
     }
     case AST_BINARY_EXPR: {
@@ -370,7 +416,6 @@ static void typecheck_ast_node(struct ast_node *function, struct ast_node *node)
   }
 }
 
-
 /* Type checker - WIP  */
 static void typecheck_function(struct ast_node *func) {
   typecheck_ast_list(func, func->function_expr.function_statement_list);