A quine (#470)

* Add quine.wybe sample

* Fix typo in json; add more details in sammples/README.md

* Formatting; authorship

* Add complex test with shorter quine

* Better validation in README

samples/README.md

@@ -1 +1,21 @@
-Some small example Wybe programs.
+# Some small example Wybe programs.
+
+## brainfuck.wybe
+
+A [Brainfuck](https://esolangs.org/wiki/Brainfuck) parser and interpreter.
+
+## json.wybe
+
+A JSON document parser.
+
+## quine.wybe
+
+A [Quine](https://en.wikipedia.org/wiki/Quine_(computing)). 
+
+To validate:
+```sh
+$ wybemk quine 
+$ ./quine | diff ./quine.wybe -
+$ echo $?
+0
+```

samples/json.wybe

@@ -1,4 +1,4 @@
-## json.Wybe
+## json.wybe
 ## Author: James Barnes
 #
 # A recursive-descent parser for JSON documents in Wybe. 

samples/quine.wybe

@@ -0,0 +1,56 @@
+## quine.wybe
+## Author: James Barnes
+#
+# A Quine
+?listing = [
+    "## quine.wybe",
+    "## Author: James Barnes",
+    "#",
+    "# A Quine",
+    "?listing = [",
+    "]",
+    "?n_lines = listing^length",
+    "?preamble_lines = 5",
+    "for _ in 0..preamble_lines; ?line in listing {",
+    "    !println line",
+    "}",
+    "for ?index in 0..n_lines; ?line in listing {",
+    "    for _ in 0..4 {",
+    "        !print ' '",
+    "    }",
+    "    ?quote = 34:char",
+    "    !print quote; !print line; !print quote",
+    "    if { index < n_lines - 1 ::",
+    "        !println ','",
+    "      | else ::",
+    "        !nl",
+    "    }",
+    "}",
+    "for ?i in preamble_lines..n_lines {",
+    "    if { ?line = listing[i] ::",
+    "        !println(line)",
+    "    }",
+    "}"
+]
+?n_lines = listing^length
+?preamble_lines = 5
+for _ in 0..preamble_lines; ?line in listing {
+    !println line
+}
+for ?index in 0..n_lines; ?line in listing {
+    for _ in 0..4 {
+        !print ' '
+    }
+    ?quote = 34:char
+    !print quote; !print line; !print quote
+    if { index < n_lines - 1 ::
+        !println ','
+      | else ::
+        !nl
+    }
+}
+for ?i in preamble_lines..n_lines {
+    if { ?line = listing[i] ::
+        !println(line)
+    }
+}

test-cases/complex/exp/testcase_quine-quine.exp

@@ -0,0 +1,8 @@
+----------------------------------------------------------------------
+- program - output
+----------------------------------------------------------------------
+["[","]=?L;?q=34:char;if{L=[?a,?b|_]::for _ in L{!print a;!print q};!print',';for _ in L{!print q;!print b}}"]=?L;?q=34:char;if{L=[?a,?b|_]::for _ in L{!print a;!print q};!print',';for _ in L{!print q;!print b}}
+["[","]=?L;?q=34:char;if{L=[?a,?b|_]::for _ in L{!print a;!print q};!print',';for _ in L{!print q;!print b}}"]=?L;?q=34:char;if{L=[?a,?b|_]::for _ in L{!print a;!print q};!print',';for _ in L{!print q;!print b}}
+----------------------------------------------------------------------
+
+

test-cases/complex/testcase_quine.py

@@ -0,0 +1,13 @@
+from complex.utils import *
+
+WYBE_QUINE:str = r"""["[","]=?L;?q=34:char;if{L=[?a,?b|_]::for _ in L{!print a;!print q};!print',';for _ in L{!print q;!print b}}"]=?L;?q=34:char;if{L=[?a,?b|_]::for _ in L{!print a;!print q};!print',';for _ in L{!print q;!print b}}"""
+
+@test_case
+def quine(ctx: Context) -> None:
+    ctx.save_file("quine.wybe", WYBE_QUINE)
+    _ = ctx.wybe_build_target("quine", False, False, check=True)
+    _, output = ctx.execute_program("./quine", check=True)
+    ctx.write_section("program - output", "\n".join([WYBE_QUINE, output]))
+
+    assert WYBE_QUINE == output
+