unikernel/duniverse/ppxlib/test/ppxlib-pp-ast/input.t

@@ -0,0 +1,39 @@
+ppxlib-pp-ast can be used on files but it can also read from stdin:
+
+  $ cat > test.ml << EOF
+  > let x = x + 2
+  > EOF
+  $ cat test.ml | ppxlib-pp-ast --str -
+  [ Pstr_value
+      ( Nonrecursive
+      , [ { pvb_pat = Ppat_var "x"
+          ; pvb_expr =
+              Pexp_apply
+                ( Pexp_ident (Lident "+")
+                , [ ( Nolabel, Pexp_ident (Lident "x"))
+                  ; ( Nolabel, Pexp_constant (Pconst_integer ( "2", None)))
+                  ]
+                )
+          ; pvb_constraint = None
+          ; pvb_attributes = __attrs
+          ; pvb_loc = __loc
+          }
+        ]
+      )
+  ]
+
+It can also read the input directly from the command line:
+
+  $ ppxlib-pp-ast --exp "x + 2"
+  Pexp_apply
+    ( Pexp_ident (Lident "+")
+    , [ ( Nolabel, Pexp_ident (Lident "x"))
+      ; ( Nolabel, Pexp_constant (Pconst_integer ( "2", None)))
+      ]
+    )
+
+Note that the kind must be specified when the input is not a file:
+
+  $ ppxlib-pp-ast "x + 2"
+  ppxlib-pp-ast: Could not guess kind from input "x + 2". Please use relevant CLI flag.
+  [123]