_future

1. Fix index, including both start and end. So Literal[start:end+1] will
be a valid part.

2. Replace any with string, add file param type

3. Start of making the evaluator, starting with regexp for param types
(these expression can be changed or/and overriden by user later on)


Former-commit-id: ab95265f953dadbf84170b543e1ff8840f9c4a14

_future/ipel/evaluator/evaluator.go

@@ -0,0 +1,27 @@
+package evaluator
+
+import (
+	"fmt"
+	"regexp"
+)
+
+// final evaluator signature for both param types and param funcs
+type ParamEvaluator func(paramValue string) bool
+
+func NewParamEvaluatorFromRegexp(expr string) (ParamEvaluator, error) {
+	if expr == "" {
+		return nil, fmt.Errorf("empty regex expression")
+	}
+
+	// add the last $ if missing (and not wildcard(?))
+	if i := expr[len(expr)-1]; i != '$' && i != '*' {
+		expr += "$"
+	}
+
+	r, err := regexp.Compile(expr)
+	if err != nil {
+		return nil, err
+	}
+
+	return r.MatchString, nil
+}

_future/ipel/evaluator/param.go

@@ -0,0 +1,56 @@
+package evaluator
+
+import (
+	"gopkg.in/kataras/iris.v6/_future/ipel/ast"
+)
+
+// exported to be able to change how param types are evaluating
+var ParamTypeEvaluator = make(map[ast.ParamType]ParamEvaluator, 0)
+
+func init() {
+
+	// string type
+	// anything.
+	stringRegex, err := NewParamEvaluatorFromRegexp(".*")
+	if err != nil {
+		panic(err)
+	}
+	ParamTypeEvaluator[ast.ParamTypeString] = stringRegex
+
+	// int type
+	// only numbers (0-9)
+	numRegex, err := NewParamEvaluatorFromRegexp("[0-9]+$")
+	if err != nil {
+		panic(err)
+	}
+	ParamTypeEvaluator[ast.ParamTypeInt] = numRegex
+
+	// alphabetical/letter type
+	// letters only (upper or lowercase)
+	alphabeticRegex, err := NewParamEvaluatorFromRegexp("[a-zA-Z]+$")
+	if err != nil {
+		panic(err)
+	}
+	ParamTypeEvaluator[ast.ParamTypeAlphabetical] = alphabeticRegex
+
+	// file type
+	// letters (upper or lowercase)
+	// numbers (0-9)
+	// underscore (_)
+	// dash (-)
+	// point (.)
+	// no spaces! or other character
+	fileRegex, err := NewParamEvaluatorFromRegexp("[a-zA-Z0-9_.-]*$")
+	if err != nil {
+		panic(err)
+	}
+	ParamTypeEvaluator[ast.ParamTypeFile] = fileRegex
+
+	// path type
+	// file with slashes(anywhere)
+	pathRegex, err := NewParamEvaluatorFromRegexp("[a-zA-Z0-9_.-/]*$")
+	if err != nil {
+		panic(err)
+	}
+	ParamTypeEvaluator[ast.ParamTypePath] = pathRegex
+}