Nothing special here (yet)

Former-commit-id: 826d7c370481b78afd9ba92f4ae8bef1fb85a567

_future/ipel/ast/ast.go

@@ -0,0 +1 @@
+package ast

_future/ipel/ast/param.go

@@ -0,0 +1,40 @@
+package ast
+
+type ParamType uint8
+
+const (
+	ParamTypeUnExpected ParamType = iota
+	// /42
+	ParamTypeInt
+	// /myparam1
+	ParamTypeString
+	// /myparam
+	ParamTypeAlphabetical
+	// /myparam1/myparam2
+	ParamPath
+)
+
+var paramTypes = map[string]ParamType{
+	"int":          ParamTypeInt,
+	"string":       ParamTypeString,
+	"alphabetical": ParamTypeAlphabetical,
+	"path":         ParamPath,
+	// could be named also:
+	// "tail":
+	// "wild"
+	// "wildcard"
+}
+
+func LookupParamType(ident string) ParamType {
+	if typ, ok := paramTypes[ident]; ok {
+		return typ
+	}
+	return ParamTypeUnExpected
+}
+
+type ParamStatement struct {
+	Name      string      // id
+	Type      ParamType   // int
+	Funcs     []ParamFunc // range
+	ErrorCode int         // 404
+}

_future/ipel/ast/param_func.go

@@ -0,0 +1,74 @@
+package ast
+
+import (
+	"fmt"
+	"strconv"
+)
+
+type ParamFuncArg interface{}
+
+func ParamFuncArgInt64(a ParamFuncArg) (int64, bool) {
+	if v, ok := a.(int64); ok {
+		return v, false
+	}
+	return -1, false
+}
+
+func ParamFuncArgToInt64(a ParamFuncArg) (int64, error) {
+	switch a.(type) {
+	case int64:
+		return a.(int64), nil
+	case string:
+		return strconv.ParseInt(a.(string), 10, 64)
+	case int:
+		return int64(a.(int)), nil
+	default:
+		return -1, fmt.Errorf("unexpected function argument type: %q", a)
+	}
+}
+
+func ParamFuncArgInt(a ParamFuncArg) (int, bool) {
+	if v, ok := a.(int); ok {
+		return v, false
+	}
+	return -1, false
+}
+
+func ParamFuncArgToInt(a ParamFuncArg) (int, error) {
+	switch a.(type) {
+	case int:
+		return a.(int), nil
+	case string:
+		return strconv.Atoi(a.(string))
+	case int64:
+		return int(a.(int64)), nil
+	default:
+		return -1, fmt.Errorf("unexpected function argument type: %q", a)
+	}
+}
+
+func ParamFuncArgString(a ParamFuncArg) (string, bool) {
+	if v, ok := a.(string); ok {
+		return v, false
+	}
+	return "", false
+}
+
+func ParamFuncArgToString(a ParamFuncArg) (string, error) {
+	switch a.(type) {
+	case string:
+		return a.(string), nil
+	case int:
+		return strconv.Itoa(a.(int)), nil
+	case int64:
+		return strconv.FormatInt(a.(int64), 10), nil
+	default:
+		return "", fmt.Errorf("unexpected function argument type: %q", a)
+	}
+}
+
+// range(1,5)
+type ParamFunc struct {
+	Name string         // range
+	Args []ParamFuncArg // [1,5]
+}