Type checking of expressions / functions!

This is a bit of a chonky commit, but it adds in the basics of checking
the types of expressions / function calls / return types. There's still
a lot of work to be done, including:

(1) Adding new core types, and casting between allowed types
    automatically
(2) Picking the corrent output type based on input types (for instance
    float+int == float)
(3) We need much better error reporting, the error messages are really
    vague and unhelpful as-is
(4) We also need to work to ensure that a function with a return type
    actually returns
(5) Possible re-factoring to make stuff less hacky when we have more
    types / structs / arrays / etc.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/ast.h b/src/ast.h
index 0966550..6773c0b 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -73,6 +73,8 @@ typedef struct data_type_node {
 
 Type *type_new(DataType type);
 i64 size_for_type(Type *type);
+bool type_equals(Type *a, Type *b);
+void print_type_to_file(FILE *out, Type *type);
 
 typedef struct {
     char *name;
@@ -83,6 +85,7 @@ typedef struct {
 typedef struct ast_node Node;
 typedef struct ast_node {
     NodeType type;
+    Type *expr_type;
 
     union {
         // Binary expr
@@ -163,4 +166,6 @@ typedef struct ast_node {
 void Node_add_child(Node *parent, Node *child);
 Node *Node_new(NodeType type);
 
+Node *Node_from_int_literal(i64 value);
+
 void print_ast(Node *node);
\ No newline at end of file