Added arbitrary length functions.

README.md

@@ -17,7 +17,7 @@ include the [Unity](https://github.com/ThrowTheSwitch/Unity) test framework.
 - [x] Negative numbers
 - [x] Basic binary infix operators; `+`, `-`, `*`, `/`
 - [x] The same as conventional functions; `sum()`, `sub()`, `mul()`, `div()`
-- [ ] Arbitrary length functions
+- [x] Arbitrary length functions
 - [ ] User-defined variables
 - [ ] Control flow
 - [ ] User-defined functions

src/exec.c

@@ -41,6 +41,12 @@ ASTNumData exec_call(AST* ast) {
         ASTNumData n2 = exec_expr(calldata->argv[1]);
 
         return n1 / n2;
+    } else if (!strcmp(calldata->to, "sum") && calldata->argc == 3) {
+        ASTNumData n1 = exec_expr(calldata->argv[0]);
+        ASTNumData n2 = exec_expr(calldata->argv[1]);
+        ASTNumData n3 = exec_expr(calldata->argv[2]);
+
+        return n1 + n2 + n3;
     }
     return -1000;
 }

src/grammar.y

@@ -17,6 +17,7 @@
     double fval;
     char* strval;
     AST* ast;
+    ArgArr* argarr;
 }
 
 %define parse.error verbose
@@ -41,6 +42,8 @@
 
 %type<fval> num;
 %type<ast> exp;
+%type<argarr> arg;
+%type<argarr> argstart;
 
 %%
 
@@ -54,15 +57,35 @@ num:
     | SUB NUM { $$ = -$2; } %prec NEG
     ;
 
+argstart:
+    exp {
+        ArgArr* argarr = argarr_init();
+        argarr_add(argarr, $1);
+        $$ = argarr;
+    }
+
+arg:
+    argstart { $$ = $1; }
+    | arg SEP exp {
+        argarr_add($1, $3);
+        $$ = $1;
+    }
+    ;
+
 exp:
     num { $$ = ast_init(AST_TYPE_NUM, ast_num_data_init($1)); }
 
-    // name(thing, thing)
+    // name(thing-1, thing-2, ..., thing-n)
-    | CALL LGROUP exp SEP exp RGROUP {
+    // name(thing)
-        AST** argv = calloc(2, sizeof(AST*));
+    // name()
-        argv[0] = $3;
+
-        argv[1] = $5;
+    // larg: lgroup marg
-        $$ = ast_init(AST_TYPE_CALL, ast_call_data_init($1, 2, argv));
+    //       lgroup rgroup
+    // marg: exp sep marg
+    //       exp rgroup
+
+    | CALL LGROUP arg RGROUP {
+        $$ = ast_init(AST_TYPE_CALL, ast_call_data_init($1, $3->ln, $3->buf));
     }
 
     | exp PLUS exp {

src/include/lexer.h

@@ -2,11 +2,27 @@
 #define LEXER_H
 
 #include <assert.h>
+#include <stddef.h>
+
+#include "ast.h"
+
+#define ARLN 8
+
+extern char* inp;
+
+typedef struct {
+    size_t sz;
+    size_t ln;
+    AST** buf;
+} ArgArr;
+
+ArgArr* argarr_init();
+void argarr_destroy(ArgArr* argarr);
+void argarr_add(ArgArr* argarr, AST* arg);
 
 #include "../../build/grammars/grammar.tab.h"
 
 extern YYSTYPE yylval;
-extern char* inp;
 
 // Accumulate an integer.
 int acc_int(int c);

src/lexer.c

@@ -1,11 +1,43 @@
+#include <complex.h>
 #include <ctype.h>
 #include <limits.h>
 #include <math.h>
 #include <stdio.h>
 
 #include "include/dstr.h"
+#include "include/util.h"
 #include "include/lexer.h"
 
+ArgArr* argarr_init() {
+    ArgArr* argarr = malloc(sizeof(ArgArr));
+
+    argarr->sz = ARLN;
+    argarr->ln = 0;
+    argarr->buf = malloc(ARLN);
+
+    return argarr;
+}
+
+void argarr_destroy(ArgArr* argarr) {
+    free(argarr->buf);
+    free(argarr);
+}
+
+void argarr_add(ArgArr* argarr, AST* arg) {
+    if (argarr->ln + 1 > argarr->sz) {
+        argarr->sz *= 2;
+        argarr->buf = realloc(argarr->buf, argarr->sz);
+        log_dbgf(
+            "ArgArr @ %p doubled from %ld to %ld",
+            argarr,
+            argarr->sz/2,
+            argarr->sz
+        );
+    }
+
+    argarr->buf[argarr->ln++] = arg;
+}
+
 int acc_int(int c) {
     int value = c - '0';
     while (isdigit(*inp)) {