Feat: lots of convenience stuff

tests/forth/list_words.rs

@@ -83,3 +83,99 @@ fn cycle_zero_count_error() {
 fn choose_zero_count_error() {
     expect_error("1 2 3 0 choose", "choose count must be > 0");
 }
+
+// Bracket syntax tests
+
+#[test]
+fn bracket_cycle() {
+    let ctx = ctx_with(|c| c.runs = 0);
+    let f = run_ctx("[ 10 20 30 ] cycle", &ctx);
+    assert_eq!(stack_int(&f), 10);
+
+    let ctx = ctx_with(|c| c.runs = 1);
+    let f = run_ctx("[ 10 20 30 ] cycle", &ctx);
+    assert_eq!(stack_int(&f), 20);
+
+    let ctx = ctx_with(|c| c.runs = 2);
+    let f = run_ctx("[ 10 20 30 ] cycle", &ctx);
+    assert_eq!(stack_int(&f), 30);
+
+    let ctx = ctx_with(|c| c.runs = 3);
+    let f = run_ctx("[ 10 20 30 ] cycle", &ctx);
+    assert_eq!(stack_int(&f), 10);
+}
+
+#[test]
+fn bracket_with_quotations() {
+    let ctx = ctx_with(|c| c.runs = 0);
+    let f = run_ctx("5 [ { 3 + } { 5 + } ] cycle", &ctx);
+    assert_eq!(stack_int(&f), 8);
+
+    let ctx = ctx_with(|c| c.runs = 1);
+    let f = run_ctx("5 [ { 3 + } { 5 + } ] cycle", &ctx);
+    assert_eq!(stack_int(&f), 10);
+}
+
+#[test]
+fn bracket_nested() {
+    let ctx = ctx_with(|c| { c.runs = 0; c.iter = 0; });
+    let f = run_ctx("[ [ 10 20 ] cycle [ 30 40 ] cycle ] pcycle", &ctx);
+    assert_eq!(stack_int(&f), 10);
+
+    let ctx = ctx_with(|c| { c.runs = 0; c.iter = 1; });
+    let f = run_ctx("[ [ 10 20 ] cycle [ 30 40 ] cycle ] pcycle", &ctx);
+    assert_eq!(stack_int(&f), 30);
+}
+
+#[test]
+fn bracket_with_generator() {
+    let ctx = ctx_with(|c| c.runs = 0);
+    let f = run_ctx("[ 1 4 .. ] cycle", &ctx);
+    assert_eq!(stack_int(&f), 1);
+
+    let ctx = ctx_with(|c| c.runs = 3);
+    let f = run_ctx("[ 1 4 .. ] cycle", &ctx);
+    assert_eq!(stack_int(&f), 4);
+}
+
+#[test]
+fn stray_bracket_error() {
+    expect_error("10 ] cycle", "unexpected ]");
+}
+
+#[test]
+fn unclosed_bracket_error() {
+    expect_error("[ 10 20", "missing ]");
+}
+
+// Index tests
+
+#[test]
+fn index_basic() {
+    expect_int("10 20 30 3 1 index", 20);
+}
+
+#[test]
+fn index_with_brackets() {
+    expect_int("[ 10 20 30 ] 1 index", 20);
+}
+
+#[test]
+fn index_modulo_wraps() {
+    expect_int("[ 10 20 30 ] 5 index", 30);
+}
+
+#[test]
+fn index_negative_wraps() {
+    expect_int("[ 10 20 30 ] -1 index", 30);
+}
+
+#[test]
+fn index_with_quotation() {
+    expect_int("5 [ { 3 + } { 5 + } ] 0 index", 8);
+}
+
+#[test]
+fn index_zero_count_error() {
+    expect_error("0 0 index", "index count must be > 0");
+}