add token reader example

Author: Herringway

.github/workflows/d.yml

@@ -44,6 +44,7 @@ jobs:
         dub build dyaml:resolver
         dub build dyaml:testsuite
         dub build dyaml:tojson
+        dub build dyaml:tokens
         dub build dyaml:yaml_gen
         dub build dyaml:yaml_stats
   ninja:

dub.json

@@ -28,6 +28,7 @@
         "examples/representer",
         "examples/resolver",
         "examples/tojson",
+        "examples/tokens",
         "examples/yaml_bench",
         "examples/yaml_gen",
         "examples/yaml_stats",

examples/tokens/dub.json

@@ -0,0 +1,8 @@
+{
+    "name": "tokens",
+    "targetType": "executable",
+    "dependencies":
+    {
+        "dyaml": "*"
+    }
+}

examples/tokens/source/app.d

@@ -0,0 +1,148 @@
+module dyaml.testsuite;
+
+import dyaml;
+import dyaml.event;
+
+import std.algorithm;
+import std.conv;
+import std.file;
+import std.format;
+import std.getopt;
+import std.json;
+import std.path;
+import std.range;
+import std.stdio;
+import std.string;
+import std.typecons;
+import std.utf;
+import std.uni;
+
+void dumpEventString(string str) @safe
+{
+    auto events = Loader.fromString(str).parse();
+    foreach (event; events)
+    {
+        string line;
+        final switch (event.id)
+        {
+            case EventID.scalar:
+                line = "=VAL ";
+                if (event.anchor != "")
+                {
+                    line ~= text("&", event.anchor, " ");
+                }
+                if (event.tag != "")
+                {
+                    line ~= text("<", event.tag, "> ");
+                }
+                switch(event.scalarStyle)
+                {
+                    case ScalarStyle.singleQuoted:
+                        line ~= "'";
+                        break;
+                    case ScalarStyle.doubleQuoted:
+                        line ~= '"';
+                        break;
+                    case ScalarStyle.literal:
+                        line ~= "|";
+                        break;
+                    case ScalarStyle.folded:
+                        line ~= ">";
+                        break;
+                    default:
+                        line ~= ":";
+                        break;
+                }
+                if (event.value != "")
+                {
+                    line ~= text(event.value.substitute("\n", "\\n", `\`, `\\`, "\r", "\\r", "\t", "\\t", "\b", "\\b"));
+                }
+                break;
+            case EventID.streamStart:
+                line = "+STR";
+                break;
+            case EventID.documentStart:
+                line = "+DOC";
+                if (event.explicitDocument)
+                {
+                    line ~= text(" ---");
+                }
+                break;
+            case EventID.mappingStart:
+                line = "+MAP";
+                if (event.collectionStyle == CollectionStyle.flow)
+                {
+                    line ~= text(" {}");
+                }
+                if (event.anchor != "")
+                {
+                    line ~= text(" &", event.anchor);
+                }
+                if (event.tag != "")
+                {
+                    line ~= text(" <", event.tag, ">");
+                }
+                break;
+            case EventID.sequenceStart:
+                line = "+SEQ";
+                if (event.collectionStyle == CollectionStyle.flow)
+                {
+                    line ~= text(" []");
+                }
+                if (event.anchor != "")
+                {
+                    line ~= text(" &", event.anchor);
+                }
+                if (event.tag != "")
+                {
+                    line ~= text(" <", event.tag, ">");
+                }
+                break;
+            case EventID.streamEnd:
+                line = "-STR";
+                break;
+            case EventID.documentEnd:
+                line = "-DOC";
+                if (event.explicitDocument)
+                {
+                    line ~= " ...";
+                }
+                break;
+            case EventID.mappingEnd:
+                line = "-MAP";
+                break;
+            case EventID.sequenceEnd:
+                line = "-SEQ";
+                break;
+            case EventID.alias_:
+                line = text("=ALI *", event.anchor);
+                break;
+            case EventID.invalid:
+                assert(0, "Invalid EventID produced");
+        }
+        writeln(line);
+    }
+}
+void dumpTokens(string str) @safe
+{
+    writefln("%(%s\n%)", Loader.fromString(str).parse());
+}
+
+
+void main(string[] args) @system
+{
+    bool tokens;
+    getopt(args,
+        "t|tokens", &tokens);
+    string str;
+    if (args[1] == "-") {
+        str = cast(string)(stdin.byChunk(4096).joiner().array);
+    } else {
+        str = readText(args[1]);
+    }
+    if (tokens) {
+        dumpTokens(str);
+    } else {
+        dumpEventString(str);
+    }
+}