Add lex_is lexer method

For testing the current token without advancing the lexer.

src/lex.c

@@ -88,13 +88,19 @@ lex_scan(struct lexer *l) {
     }
 }
 
+// Return 1 if current token is type `t`,
+// 0 otherwise.
+int
+lex_is(struct lexer *l, enum tok_type t) {
+    return l->tok.cls == t;
+}
+
 // Assert current token type.
 // If assertion passes, returns 1 and advances lexer,
 // otherwise returns 0 and does not advance lexer.
 int
-lex_consume(struct lexer *l, enum tok_type want) {
-    enum tok_type curr = l->tok.cls;
-    if (curr == want) {
+lex_consume(struct lexer *l, enum tok_type t) {
+    if (lex_is(l, t)) {
         lex_scan(l);
         return 1;
     } else {
@@ -106,12 +112,12 @@ lex_consume(struct lexer *l, enum tok_type want) {
 // If assertion passes, returns 1 and advances lexer,
 // otherwise prints an error message and dies.
 int
-lex_consumef(struct lexer *l, enum tok_type want) {
-    if (!lex_consume(l, want)) {
+lex_consumef(struct lexer *l, enum tok_type t) {
+    if (!lex_consume(l, t)) {
         fprintf(
             stderr,
             "Expected token '%s', got '%s'\n",
-            lilc_token_str[want], lilc_token_str[l->tok.cls]
+            lilc_token_str[t], lilc_token_str[l->tok.cls]
         );
         exit(1);
     }

src/lex.h

@@ -12,8 +12,9 @@ struct lexer {
 };
 
 void lex_init(struct lexer *l, char *source);
-int lex_consume(struct lexer *l, enum tok_type want);
-int lex_consumef(struct lexer *l, enum tok_type want);
+int lex_is(struct lexer *l, enum tok_type t);
+int lex_consume(struct lexer *l, enum tok_type t);
+int lex_consumef(struct lexer *l, enum tok_type t);
 enum tok_type lex_scan(struct lexer *l);
 int tok_strm_readf(char *buf, struct lexer *l);
 

src/parse.c

@@ -86,8 +86,8 @@ funcdef_prefix(struct parser *p, struct token t) {
 
     char *params[MAX_FUNC_PARAMS];
     unsigned int param_count = 0;
-    while (p->lex->tok.cls != LILC_TOK_RPAREN && param_count <= MAX_FUNC_PARAMS) {
-        if (p->lex->tok.cls != LILC_TOK_ID) {
+    while (!lex_is(p->lex, LILC_TOK_RPAREN) && param_count <= MAX_FUNC_PARAMS) {
+        if (!lex_is(p->lex, LILC_TOK_ID)) {
             fprintf(stderr, "Expected id, got %s", lilc_token_str[p->lex->tok.cls]);
             exit(1);
         }
@@ -194,7 +194,7 @@ program(struct parser *p) {
     struct lilc_block_node_t *block = lilc_block_node_new();
 
     lex_scan(p->lex);  // Load first token
-    while (p->lex->tok.cls != LILC_TOK_EOS) {
+    while (!lex_is(p->lex, LILC_TOK_EOS)) {
         node = stmt(p);
         kv_push(struct lilc_node_t *, *block->stmts, node);
         lex_consumef(p->lex, LILC_TOK_SEMI);