From ea8a9e98457500b1fe73a6578aed91f174053382 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Matczuk?= <michal@scylladb.com>
Date: Wed, 30 Aug 2017 10:27:18 +0200
Subject: [PATCH] cmp: token builder

---
 qb/token.go      | 114 +++++++++++++++++++++++++++++++++++++++++++++++
 qb/token_test.go |  82 ++++++++++++++++++++++++++++++++++
 2 files changed, 196 insertions(+)
 create mode 100644 qb/token.go
 create mode 100644 qb/token_test.go

diff --git a/qb/token.go b/qb/token.go
new file mode 100644
index 0000000..dc32cc1
--- /dev/null
+++ b/qb/token.go
@@ -0,0 +1,114 @@
+package qb
+
+import (
+	"fmt"
+	"strings"
+)
+
+// Token creates a new TokenBuilder.
+func Token(columns ...string) TokenBuilder {
+	return TokenBuilder(columns)
+}
+
+// TokenBuilder helps implement pagination using token function.
+type TokenBuilder []string
+
+// Eq produces token(column)=token(?).
+func (t TokenBuilder) Eq() Cmp {
+	return Cmp{
+		op:     eq,
+		fn:     "token",
+		column: fmt.Sprint("token(", strings.Join(t, ","), ")"),
+		names:  t,
+	}
+}
+
+// EqNamed produces token(column)=token(?) with a custom parameter name.
+func (t TokenBuilder) EqNamed(names ...string) Cmp {
+	return Cmp{
+		op:     eq,
+		fn:     "token",
+		column: fmt.Sprint("token(", strings.Join(t, ","), ")"),
+		names:  names,
+	}
+}
+
+// Lt produces token(column)<token(?).
+func (t TokenBuilder) Lt() Cmp {
+	return Cmp{
+		op:     lt,
+		fn:     "token",
+		column: fmt.Sprint("token(", strings.Join(t, ","), ")"),
+		names:  t,
+	}
+}
+
+// LtNamed produces token(column)<token(?) with a custom parameter name.
+func (t TokenBuilder) LtNamed(names ...string) Cmp {
+	return Cmp{
+		op:     lt,
+		fn:     "token",
+		column: fmt.Sprint("token(", strings.Join(t, ","), ")"),
+		names:  names,
+	}
+}
+
+// LtOrEq produces token(column)<=token(?).
+func (t TokenBuilder) LtOrEq() Cmp {
+	return Cmp{
+		op:     leq,
+		fn:     "token",
+		column: fmt.Sprint("token(", strings.Join(t, ","), ")"),
+		names:  t,
+	}
+}
+
+// LtOrEqNamed produces token(column)<=token(?) with a custom parameter name.
+func (t TokenBuilder) LtOrEqNamed(names ...string) Cmp {
+	return Cmp{
+		op:     leq,
+		fn:     "token",
+		column: fmt.Sprint("token(", strings.Join(t, ","), ")"),
+		names:  names,
+	}
+}
+
+// Gt produces token(column)>token(?).
+func (t TokenBuilder) Gt() Cmp {
+	return Cmp{
+		op:     gt,
+		fn:     "token",
+		column: fmt.Sprint("token(", strings.Join(t, ","), ")"),
+		names:  t,
+	}
+}
+
+// GtNamed produces token(column)>token(?) with a custom parameter name.
+func (t TokenBuilder) GtNamed(names ...string) Cmp {
+	return Cmp{
+		op:     gt,
+		fn:     "token",
+		column: fmt.Sprint("token(", strings.Join(t, ","), ")"),
+		names:  names,
+	}
+}
+
+// GtOrEq produces token(column)>=token(?).
+func (t TokenBuilder) GtOrEq() Cmp {
+	return Cmp{
+		op:     geq,
+		fn:     "token",
+		column: fmt.Sprint("token(", strings.Join(t, ","), ")"),
+		names:  t,
+	}
+}
+
+// GtOrEqNamed produces token(column)>=token(?) with a custom parameter name.
+func (t TokenBuilder) GtOrEqNamed(names ...string) Cmp {
+	return Cmp{
+		op:     geq,
+		fn:     "token",
+		column: fmt.Sprint("token(", strings.Join(t, ","), ")"),
+		names:  names,
+	}
+}
diff --git a/qb/token_test.go b/qb/token_test.go
new file mode 100644
index 0000000..58146fc
--- /dev/null
+++ b/qb/token_test.go
@@ -0,0 +1,82 @@
+package qb
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func TestToken(t *testing.T) {
+	table := []struct {
+		C Cmp
+		S string
+		N []string
+	}{
+		// Basic comparators
+		{
+			C: Token("a", "b").Eq(),
+			S: "token(a,b)=token(?,?)",
+			N: []string{"a", "b"},
+		},
+		{
+			C: Token("a", "b").Lt(),
+			S: "token(a,b)<token(?,?)",
+			N: []string{"a", "b"},
+		},
+		{
+			C: Token("a", "b").LtOrEq(),
+			S: "token(a,b)<=token(?,?)",
+			N: []string{"a", "b"},
+		},
+		{
+			C: Token("a", "b").Gt(),
+			S: "token(a,b)>token(?,?)",
+			N: []string{"a", "b"},
+		},
+		{
+			C: Token("a", "b").GtOrEq(),
+			S: "token(a,b)>=token(?,?)",
+			N: []string{"a", "b"},
+		},
+
+		// Custom bind names
+		{
+			C: Token("a", "b").EqNamed("c", "d"),
+			S: "token(a,b)=token(?,?)",
+			N: []string{"c", "d"},
+		},
+		{
+			C: Token("a", "b").LtNamed("c", "d"),
+			S: "token(a,b)<token(?,?)",
+			N: []string{"c", "d"},
+		},
+		{
+			C: Token("a", "b").LtOrEqNamed("c", "d"),
+			S: "token(a,b)<=token(?,?)",
+			N: []string{"c", "d"},
+		},
+		{
+			C: Token("a", "b").GtNamed("c", "d"),
+			S: "token(a,b)>token(?,?)",
+			N: []string{"c", "d"},
+		},
+		{
+			C: Token("a", "b").GtOrEqNamed("c", "d"),
+			S: "token(a,b)>=token(?,?)",
+			N: []string{"c", "d"},
+		},
+	}
+
+	buf := bytes.Buffer{}
+	for _, test := range table {
+		buf.Reset()
+		name := test.C.writeCql(&buf)
+		if diff := cmp.Diff(test.S, buf.String()); diff != "" {
+			t.Error(diff)
+		}
+		if diff := cmp.Diff(test.N, name); diff != "" {
+			t.Error(diff)
+		}
+	}
+}