From 4039abd10db42e9b673441a53c163e3fcf9fe61a Mon Sep 17 00:00:00 2001
From: hanez <you@hanez.org>
Date: Thu, 11 Dec 2025 22:51:23 +0100
Subject: [PATCH] Added new example that shows the usage of random_int() and
 random_seed(). Related parser fixes. (0.37.6)

---
 CMakeLists.txt                 |  2 +-
 examples/builtins_extended.fun |  6 +--
 examples/random_demo.fun       | 81 ++++++++++++++++++++++++++++++++++
 src/parser.c                   | 11 ++---
 4 files changed, 91 insertions(+), 9 deletions(-)
 create mode 100644 examples/random_demo.fun

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 142212e..45f83ae 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.10)
-project(fun VERSION 0.37.5 LANGUAGES C)
+project(fun VERSION 0.37.6 LANGUAGES C)
 
 set(CMAKE_C_STANDARD 99)
 set(CMAKE_C_STANDARD_REQUIRED ON)
diff --git a/examples/builtins_extended.fun b/examples/builtins_extended.fun
index 7c9fe9f..aac791e 100755
--- a/examples/builtins_extended.fun
+++ b/examples/builtins_extended.fun
@@ -45,9 +45,9 @@ print(max(5, 9))                         // -> 9
 print(clamp(15, 0, 10))                  // -> 10
 print(abs(-7))                           // -> 7
 print(pow(2, 8))                         // -> 256
-random(123)                              // seed RNG
-print(randomInt(0, 3))                   // -> 0..2 (deterministic for seed 123)
-print(randomInt(5, 6))                   // -> 5
+random_seed(123)                              // seed RNG
+print(random_int(0, 3))                   // -> 0..2 (deterministic for seed 123)
+print(random_int(5, 6))                   // -> 5
 
 /* Expected output:
 a-b-c
diff --git a/examples/random_demo.fun b/examples/random_demo.fun
new file mode 100644
index 0000000..6ec0a36
--- /dev/null
+++ b/examples/random_demo.fun
@@ -0,0 +1,81 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2025-12-11
+ */
+
+// Demonstrates usage of RANDOM_SEED and RANDOM_INT opcodes via
+// the built-ins: random_seed(seed) and random_int(lo, hiExclusive).
+
+print("-- Random demo: seed reproducibility and bounds --")
+
+// Seed with a fixed value and produce a short sequence
+seed = 123456
+random_seed(seed)
+a1 = random_int(0, 10)   // in [0,10)
+a2 = random_int(0, 10)
+a3 = random_int(5, 8)    // in [5,8)
+
+print("First run:")
+print(a1)
+print(a2)
+print(a3)
+
+// Re-seed with the same value: the sequence should repeat
+random_seed(seed)
+b1 = random_int(0, 10)
+b2 = random_int(0, 10)
+b3 = random_int(5, 8)
+
+print("Second run (after re-seed):")
+print(b1)
+print(b2)
+print(b3)
+
+print("Reproducible? (a1==b1, a2==b2, a3==b3)")
+print(a1 == b1)
+print(a2 == b2)
+print(a3 == b3)
+
+// Show that the upper bound is exclusive by sampling multiple times
+// and tracking the maximum seen value; it should never reach hi.
+lo = 10
+hi = 20
+max_seen = lo
+i = 0
+while i < 100
+  v = random_int(lo, hi)
+  if (v > max_seen) max_seen = v
+  i = i + 1
+
+print("Max seen in [" + to_string(lo) + "," + to_string(hi) + ") over 100 samples:")
+print(max_seen)
+print("Is max_seen < hi? ")
+print(max_seen < hi)
+
+/* Expected output:
+-- Random demo: seed reproducibility and bounds --
+First run:
+9
+3
+5
+Second run (after re-seed):
+9
+3
+5
+Reproducible? (a1==b1, a2==b2, a3==b3)
+true
+true
+true
+Max seen in [10,20) over 100 samples:
+19
+Is max_seen < hi? 
+1
+*/
diff --git a/src/parser.c b/src/parser.c
index 17f1eca..b665f16 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -1632,17 +1632,18 @@ static int emit_primary(Bytecode *bc, const char *src, size_t len, size_t *pos)
                 free(name);
                 return 1;
             }
-            if (strcmp(name, "random") == 0) {
+
+            if (strcmp(name, "random_seed") == 0) {
                 (*pos)++; /* '(' */
-                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "random expects 1 arg"); free(name); return 0; }
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "random_seed expects 1 arg"); free(name); return 0; }
                 bytecode_add_instruction(bc, OP_RANDOM_SEED, 0);
                 free(name);
                 return 1;
             }
-            if (strcmp(name, "randomInt") == 0) {
+            if (strcmp(name, "random_int") == 0) {
                 (*pos)++; /* '(' */
-                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ',')) { parser_fail(*pos, "randomInt expects 2 args"); free(name); return 0; }
-                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "randomInt expects 2 args"); free(name); return 0; }
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ',')) { parser_fail(*pos, "random_int expects 2 args"); free(name); return 0; }
+                if (!emit_expression(bc, src, len, pos) || !consume_char(src, len, pos, ')')) { parser_fail(*pos, "random_int expects 2 args"); free(name); return 0; }
                 bytecode_add_instruction(bc, OP_RANDOM_INT, 0);
                 free(name);
                 return 1;