Use 'fn' to define closure to make parsing/reading the language easier

It caused issues when you have parentheses to surround math expression,
for example: ((func() + 34) * 54)
is easier to parse if closure has to begin with 'fn'.

Also removed requirement for semicolons. Semicolons can't even be used
optionally yet.

2 files changed, 36 insertions, 22 deletions

diff --git a/src/parser.c b/src/parser.c
index 539ebd3..babb2d9 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -94,20 +94,24 @@ static CHECK_RESULT int parser_parse_lhs(Parser *self, LhsExpr **result) {
 }
 
 /*
-CLOSURE = '(' PARAM* ')' '{' BODY_LOOP '}'
+CLOSURE = 'fn' ('(' PARAM* ')')? '{' BODY_LOOP '}'
 */
 static CHECK_RESULT int parser_parse_function_decl(Parser *self, FunctionDecl **func_decl) {
-    bool result;
+    bool match;
     *func_decl = NULL;
 
-    return_if_error(tokenizer_consume_if(&self->tokenizer, TOK_OPEN_PAREN, &result));
-    if(!result)
+    return_if_error(tokenizer_consume_if(&self->tokenizer, TOK_FN, &match));
+    if(!match)
         return PARSER_OK;
 
-    /* TODO: Parse parameters */
-    return_if_error(tokenizer_accept(&self->tokenizer, TOK_CLOSING_PAREN));
-    /* TODO: Parse return types */
-    return_if_error(tokenizer_accept(&self->tokenizer, TOK_OPEN_BRACE));
+    return_if_error(tokenizer_consume_if(&self->tokenizer, TOK_OPEN_BRACE, &match));
+    if(!match) {
+        return_if_error(tokenizer_accept(&self->tokenizer, TOK_OPEN_PAREN));
+        /* TODO: Parse parameters */
+        return_if_error(tokenizer_accept(&self->tokenizer, TOK_CLOSING_PAREN));
+        /* TODO: Parse return types */
+        return_if_error(tokenizer_accept(&self->tokenizer, TOK_OPEN_BRACE));
+    }
 
     return_if_error(scoped_allocator_alloc(self->allocator, sizeof(FunctionDecl), (void**)func_decl));
     return_if_error(funcdecl_init(*func_decl, self->allocator));
@@ -147,17 +151,17 @@ VARIABLE = IDENTIFIER
 FUNC_CALL_OR_VARIABLE = VARIABLE '(' FUNC_ARGS ')'
 */
 static CHECK_RESULT int parser_parse_function_call_or_variable(Parser *self, Ast *expr) {
-    bool result;
+    bool match;
     BufferView identifier;
     FunctionCall *func_call;
 
-    return_if_error(tokenizer_consume_if(&self->tokenizer, TOK_IDENTIFIER, &result));
-    if(!result)
+    return_if_error(tokenizer_consume_if(&self->tokenizer, TOK_IDENTIFIER, &match));
+    if(!match)
         return PARSER_OK;
     
     identifier = self->tokenizer.value.identifier;
-    return_if_error(tokenizer_consume_if(&self->tokenizer, TOK_OPEN_PAREN, &result));
-    if(!result) {
+    return_if_error(tokenizer_consume_if(&self->tokenizer, TOK_OPEN_PAREN, &match));
+    if(!match) {
         Variable *variable;
         return_if_error(scoped_allocator_alloc(self->allocator, sizeof(Variable), (void**)&variable));
         variable->name = identifier;
@@ -177,11 +181,11 @@ static CHECK_RESULT int parser_parse_function_call_or_variable(Parser *self, Ast
 IMPORT = IMPORT_SYMBOL
 */
 static CHECK_RESULT int parser_parse_import(Parser *self, Import **import) {
-    bool result;
+    bool match;
     *import = NULL;
 
-    return_if_error(tokenizer_consume_if(&self->tokenizer, TOK_IMPORT, &result));
-    if(!result)
+    return_if_error(tokenizer_consume_if(&self->tokenizer, TOK_IMPORT, &match));
+    if(!match)
         return PARSER_OK;
     
     return_if_error(scoped_allocator_alloc(self->allocator, sizeof(Import), (void**)import));
@@ -190,11 +194,11 @@ static CHECK_RESULT int parser_parse_import(Parser *self, Import **import) {
 }
 
 static CHECK_RESULT int parser_parse_number(Parser *self, Ast *rhs_expr) {
-    bool result;
+    bool match;
     Number *number;
 
-    return_if_error(tokenizer_consume_if(&self->tokenizer, TOK_NUMBER, &result));
-    if(!result)
+    return_if_error(tokenizer_consume_if(&self->tokenizer, TOK_NUMBER, &match));
+    if(!match)
         return PARSER_OK;
     
     return_if_error(scoped_allocator_alloc(self->allocator, sizeof(Number), (void**)&number));
@@ -208,10 +212,10 @@ static CHECK_RESULT int parser_parse_number(Parser *self, Ast *rhs_expr) {
 RHS = STRING | NUMBER | FUNC_CALL_OR_VARIABLE
 */
 static CHECK_RESULT int parser_parse_rhs(Parser *self, Ast *rhs_expr) {
-    bool result;
+    bool match;
 
-    return_if_error(tokenizer_consume_if(&self->tokenizer, TOK_STRING, &result));
-    if(result) {
+    return_if_error(tokenizer_consume_if(&self->tokenizer, TOK_STRING, &match));
+    if(match) {
         String *string;
         return_if_error(scoped_allocator_alloc(self->allocator, sizeof(String), (void**)&string));
         return_if_error(string_init(string, self->tokenizer.value.string));
diff --git a/src/tokenizer.c b/src/tokenizer.c
index 41d46fb..b996354 100644
--- a/src/tokenizer.c
+++ b/src/tokenizer.c
@@ -146,6 +146,13 @@ static CHECK_RESULT int __tokenizer_next(Tokenizer *self, Token *token) {
         self->value.identifier = create_buffer_view(self->code.data + identifier_start, self->index - identifier_start);
 
         switch(self->value.identifier.size) {
+            case 2: {
+                if(am_memeql(self->value.identifier.data, "fn", 2)) {
+                    *token = TOK_FN;
+                    return TOKENIZER_OK;
+                }
+                break;
+            }
             case 3: {
                 if(am_memeql(self->value.identifier.data, "var", 3)) {
                     *token = TOK_VAR;
@@ -324,6 +331,9 @@ static BufferView tokenizer_expected_token_as_string(Token token) {
         case TOK_STRING:
             str = "string";
             break;
+        case TOK_FN:
+            str = "fn";
+            break;
         case TOK_EQUALS:
             str = "=";
             break;