Refactor AST and Parser into modular subdirectories

- Split ast.h into granular headers in v0/ast/
- Split parser.c into modular implementation files in v0/parser/
- Move and rename parser tests to v0/parser/test_*.c
- Update build system (include.mk) with modular sub-makefiles
- Maintain v0/ast.h and v0/parser.h as umbrella headers

v0/parser/expression.c

@@ -0,0 +1,105 @@
+#include "internal.h"
+#include "../log.h"
+#include <stdlib.h>
+
+bool parse_primitive_type_expression(Parser* p, TypeExpression* expr) {
+    if (parser_accept(p, TOKEN_U8)) {
+        expr->tag = TYPE_EXPRESSION_BUILTIN;
+        expr->builtin.bitSize = 8;
+        expr->builtin.isSigned = false;
+        return true;
+    } else if (parser_accept(p, TOKEN_U16)) {
+        expr->tag = TYPE_EXPRESSION_BUILTIN;
+        expr->builtin.bitSize = 16;
+        expr->builtin.isSigned = false;
+        return true;
+    } else if (parser_accept(p, TOKEN_U32)) {
+        expr->tag = TYPE_EXPRESSION_BUILTIN;
+        expr->builtin.bitSize = 32;
+        expr->builtin.isSigned = false;
+        return true;
+    } else if (parser_accept(p, TOKEN_U64)) {
+        expr->tag = TYPE_EXPRESSION_BUILTIN;
+        expr->builtin.bitSize = 64;
+        expr->builtin.isSigned = false;
+        return true;
+    } else if (parser_accept(p, TOKEN_I8)) {
+        expr->tag = TYPE_EXPRESSION_BUILTIN;
+        expr->builtin.bitSize = 8;
+        expr->builtin.isSigned = true;
+        return true;
+    } else if (parser_accept(p, TOKEN_I16)) {
+        expr->tag = TYPE_EXPRESSION_BUILTIN;
+        expr->builtin.bitSize = 16;
+        expr->builtin.isSigned = true;
+        return true;
+    } else if (parser_accept(p, TOKEN_I32)) {
+        expr->tag = TYPE_EXPRESSION_BUILTIN;
+        expr->builtin.bitSize = 32;
+        expr->builtin.isSigned = true;
+        return true;
+    } else if (parser_accept(p, TOKEN_I64)) {
+        expr->tag = TYPE_EXPRESSION_BUILTIN;
+        expr->builtin.bitSize = 64;
+        expr->builtin.isSigned = true;
+        return true;
+    } else {
+        log_on_line(&p->token.location, "expected type expression");
+        return false;
+    }
+}
+
+bool parse_array_type_expression(Parser* p, TypeExpression* expr) {
+    TypeExpression elementType;
+    if (!parse_primitive_type_expression(p, &elementType)) {
+        return false;
+    }
+
+    if (parser_accept(p, TOKEN_BRACKET_OPEN)) {
+        expr->tag = TYPE_EXPRESSION_ARRAY;
+        expr->array.array = malloc(sizeof(TypeExpression));
+        *expr->array.array = elementType;
+
+        if (!parser_expect(p, TOKEN_BRACKET_CLOSE, "expected ']' to end array type")) {
+            return false;
+        }
+    } else {
+         *expr = elementType;
+         return true;
+    }
+    return true;
+}
+
+bool parse_type_expression(Parser* p, TypeExpression* expr) {
+    return parse_array_type_expression(p, expr);
+}
+
+bool parse_expression(Parser* p, Expression* expr) {
+    if (parser_peek(p, TOKEN_INTEGER)) {
+        expr->tag = EXPRESSION_INTEGER;
+        expr->integer = atoi(p->token.text.data);
+        parser_next_token(p);
+        return true;
+    } else if (parser_peek(p, TOKEN_STRING)) {
+        expr->tag = EXPRESSION_STRING;
+        expr->string = parser_to_text(p);
+        return true;
+    } else if (parser_accept(p, TOKEN_TRUE)) {
+        expr->tag = EXPRESSION_BOOLEAN;
+        expr->boolean = true;
+        return true;
+    } else if (parser_accept(p, TOKEN_FALSE)) {
+        expr->tag = EXPRESSION_BOOLEAN;
+        expr->boolean = false;
+        return true;
+    }
+    log_on_line(&p->token.location, "expected expression");
+    return false;
+}
+
+void free_type_expression(TypeExpression* expr) {
+    if (expr->tag == TYPE_EXPRESSION_ARRAY) {
+        free_type_expression(expr->array.array);
+        free(expr->array.array);
+    }
+}