test: add property grammar example

Author: bcho

Diff for: samples/property/property_test.go

@@ -0,0 +1,52 @@
+package property
+
+import (
+	"testing"
+
+	"github.com/b4fun/parsimonious-go"
+)
+
+const grammarText = `
+Item = "-" _ KeyValuePairs _
+
+KeyValuePairs = 'item(' KeyValuePair ("," _ KeyValuePair)* ')'
+
+KeyValuePair = Key _ "=" _ Value
+
+Key = ~r"[a-zA-Z][a-zA-Z0-9_]*"
+
+Value = String / Number / KeyValuePairs
+
+String = StringLiteral / StringQuoted
+
+StringLiteral = "string(" ~r'[^)]+' ")"
+StringQuoted = "string(" _ '"' ~r'[^"]*' '"' _ ")"
+
+Number = "number(" _ ~r"[0-9]+(\.[0-9]+)?" _ ")"
+
+_ = Whitespace*
+
+Whitespace = " " / "\t" / EOL
+
+EOL = "\n" / "\r\n" / "\r"
+`
+
+func Test_Property(t *testing.T) {
+	withDebug := parsimonious.ParseWithDebug(true)
+
+	grammar, err := parsimonious.NewGrammar(grammarText, withDebug)
+	if err != nil {
+		t.Errorf("parse grammar failed: %v", err)
+		return
+	}
+
+	program := `- item(name=string( Energy中文 ), subitem=item(value=number(997), unit=string("value")))`
+	t.Logf("%q\n", program)
+
+	tree, err := grammar.Parse(program, withDebug)
+	if err != nil {
+		t.Errorf("parse sample failed: %v", err)
+		return
+	}
+	t.Log("\n" + parsimonious.DumpNodeExprTree(tree))
+}