1 files changed, 178 insertions, 0 deletions

diff --git a/vendor/github.com/hashicorp/go-version/constraint.go b/vendor/github.com/hashicorp/go-version/constraint.go
new file mode 100644
index 0000000..8c73df0
--- /dev/null
+++ b/vendor/github.com/hashicorp/go-version/constraint.go
@@ -0,0 +1,178 @@
+package version
+
+import (
+        "fmt"
+        "regexp"
+        "strings"
+)
+
+// Constraint represents a single constraint for a version, such as
+// ">= 1.0".
+type Constraint struct {
+        f        constraintFunc
+        check    *Version
+        original string
+}
+
+// Constraints is a slice of constraints. We make a custom type so that
+// we can add methods to it.
+type Constraints []*Constraint
+
+type constraintFunc func(v, c *Version) bool
+
+var constraintOperators map[string]constraintFunc
+
+var constraintRegexp *regexp.Regexp
+
+func init() {
+        constraintOperators = map[string]constraintFunc{
+                "":   constraintEqual,
+                "=":  constraintEqual,
+                "!=": constraintNotEqual,
+                ">":  constraintGreaterThan,
+                "<":  constraintLessThan,
+                ">=": constraintGreaterThanEqual,
+                "<=": constraintLessThanEqual,
+                "~>": constraintPessimistic,
+        }
+
+        ops := make([]string, 0, len(constraintOperators))
+        for k := range constraintOperators {
+                ops = append(ops, regexp.QuoteMeta(k))
+        }
+
+        constraintRegexp = regexp.MustCompile(fmt.Sprintf(
+                `^\s*(%s)\s*(%s)\s*$`,
+                strings.Join(ops, "|"),
+                VersionRegexpRaw))
+}
+
+// NewConstraint will parse one or more constraints from the given
+// constraint string. The string must be a comma-separated list of
+// constraints.
+func NewConstraint(v string) (Constraints, error) {
+        vs := strings.Split(v, ",")
+        result := make([]*Constraint, len(vs))
+        for i, single := range vs {
+                c, err := parseSingle(single)
+                if err != nil {
+                        return nil, err
+                }
+
+                result[i] = c
+        }
+
+        return Constraints(result), nil
+}
+
+// Check tests if a version satisfies all the constraints.
+func (cs Constraints) Check(v *Version) bool {
+        for _, c := range cs {
+                if !c.Check(v) {
+                        return false
+                }
+        }
+
+        return true
+}
+
+// Returns the string format of the constraints
+func (cs Constraints) String() string {
+        csStr := make([]string, len(cs))
+        for i, c := range cs {
+                csStr[i] = c.String()
+        }
+
+        return strings.Join(csStr, ",")
+}
+
+// Check tests if a constraint is validated by the given version.
+func (c *Constraint) Check(v *Version) bool {
+        return c.f(v, c.check)
+}
+
+func (c *Constraint) String() string {
+        return c.original
+}
+
+func parseSingle(v string) (*Constraint, error) {
+        matches := constraintRegexp.FindStringSubmatch(v)
+        if matches == nil {
+                return nil, fmt.Errorf("Malformed constraint: %s", v)
+        }
+
+        check, err := NewVersion(matches[2])
+        if err != nil {
+                return nil, err
+        }
+
+        return &Constraint{
+                f:        constraintOperators[matches[1]],
+                check:    check,
+                original: v,
+        }, nil
+}
+
+//-------------------------------------------------------------------
+// Constraint functions
+//-------------------------------------------------------------------
+
+func constraintEqual(v, c *Version) bool {
+        return v.Equal(c)
+}
+
+func constraintNotEqual(v, c *Version) bool {
+        return !v.Equal(c)
+}
+
+func constraintGreaterThan(v, c *Version) bool {
+        return v.Compare(c) == 1
+}
+
+func constraintLessThan(v, c *Version) bool {
+        return v.Compare(c) == -1
+}
+
+func constraintGreaterThanEqual(v, c *Version) bool {
+        return v.Compare(c) >= 0
+}
+
+func constraintLessThanEqual(v, c *Version) bool {
+        return v.Compare(c) <= 0
+}
+
+func constraintPessimistic(v, c *Version) bool {
+        // If the version being checked is naturally less than the constraint, then there
+        // is no way for the version to be valid against the constraint
+        if v.LessThan(c) {
+                return false
+        }
+        // We'll use this more than once, so grab the length now so it's a little cleaner
+        // to write the later checks
+        cs := len(c.segments)
+
+        // If the version being checked has less specificity than the constraint, then there
+        // is no way for the version to be valid against the constraint
+        if cs > len(v.segments) {
+                return false
+        }
+
+        // Check the segments in the constraint against those in the version. If the version
+        // being checked, at any point, does not have the same values in each index of the
+        // constraints segments, then it cannot be valid against the constraint.
+        for i := 0; i < c.si-1; i++ {
+                if v.segments[i] != c.segments[i] {
+                        return false
+                }
+        }
+
+        // Check the last part of the segment in the constraint. If the version segment at
+        // this index is less than the constraints segment at this index, then it cannot
+        // be valid against the constraint
+        if c.segments[cs-1] > v.segments[cs-1] {
+                return false
+        }
+
+        // If nothing has rejected the version by now, it's valid
+        return true
+}