Add dumper, pretty-print expressions in raw mode

igorw · igorw · commit 2fcc66897380 · 2013-12-28T19:22:04.000+01:00
diff --git a/README.md b/README.md
@@ -94,17 +94,7 @@ Or `r` for raw mode:
     $ php repl.php
     i> r
     r> λx.x
-    array(4) {
-      [0]=>
-      string(2) "λ"
-      [1]=>
-      string(1) "x"
-      [2]=>
-      string(1) "x"
-      [3]=>
-      array(0) {
-      }
-    }
+    λx.x
 
 ## References
 
diff --git a/composer.json b/composer.json
@@ -13,6 +13,6 @@
         "jakubledl/dissect": "dev-develop"
     },
     "autoload": {
-        "files": ["src/eval.php", "src/parser.php", "src/krivine.php", "src/binary.php"]
+        "files": ["src/util.php", "src/eval.php", "src/parser.php", "src/krivine.php", "src/binary.php", "src/dumper.php"]
     }
 }
diff --git a/composer.lock b/composer.lock
diff --git a/repl.php b/repl.php
@@ -15,9 +15,7 @@ function prompt($mode)
 
 function format_raw($result)
 {
-    ob_start();
-    var_dump($result);
-    return trim(ob_get_clean());
+    return dump($result);
 }
 
 function identity($x)
diff --git a/src/dumper.php b/src/dumper.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace igorw\lambda;
+
+function dump($exp)
+{
+    if (is_string($exp)) {
+        return $exp;
+    }
+
+    if ('λ' === first($exp)) {
+        list($_, $arg, $body) = $exp;
+        return 'λ'.dump($arg).'.'.dump($body);
+    }
+
+    list($f, $arg) = $exp;
+    return dump($f).(is_application($arg) ? '('.dump($arg).')' : dump($arg));
+}
+
+function is_application($exp)
+{
+    return is_array($exp)
+        && 'λ' !== first($exp)
+        && 2 === count($exp);
+}
diff --git a/src/eval.php b/src/eval.php
@@ -19,16 +19,6 @@
 
 namespace igorw\lambda;
 
-function first(array $list)
-{
-    return $list[0];
-}
-
-function second(array $list)
-{
-    return $list[1];
-}
-
 function evaluate($exp, array $env = [])
 {
     // actual PHP numbers and callables
diff --git a/src/util.php b/src/util.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace igorw\lambda;
+
+function first(array $list)
+{
+    return $list[0];
+}
+
+function second(array $list)
+{
+    return $list[1];
+}

Original file line number	Diff line number	Diff line change
`@@ -13,6 +13,6 @@`
`13`	`13`	`"jakubledl/dissect": "dev-develop"`
`14`	`14`	`},`
`15`	`15`	`"autoload": {`
`16`		`- "files": ["src/eval.php", "src/parser.php", "src/krivine.php", "src/binary.php"]`
	`16`	`+ "files": ["src/util.php", "src/eval.php", "src/parser.php", "src/krivine.php", "src/binary.php", "src/dumper.php"]`
`17`	`17`	`}`
`18`	`18`	`}`
Original file line number	Diff line number	Diff line change
`@@ -15,9 +15,7 @@ function prompt($mode)`
`15`	`15`
`16`	`16`	`function format_raw($result)`
`17`	`17`	`{`
`18`		`- ob_start();`
`19`		`- var_dump($result);`
`20`		`- return trim(ob_get_clean());`
	`18`	`+ return dump($result);`
`21`	`19`	`}`
`22`	`20`
`23`	`21`	`function identity($x)`