go: step1_read_print vectors and hash-maps

3 files changed, 61 insertions, 11 deletions

diff --git a/go/src/printer/printer.go b/go/src/printer/printer.go
index 83d4c84..fa1c0fb 100644
--- a/go/src/printer/printer.go
+++ b/go/src/printer/printer.go
@@ -9,14 +9,27 @@ import (
     "types"
 )
 
+func _pr_list(lst []types.MalType, pr bool, start string, end string) string {
+    str_list := make([]string, 0, len(lst))
+    for _, e := range lst {
+        str_list = append(str_list, Pr_str(e, pr))
+    }
+    return start + strings.Join(str_list, " ") + end
+}
+
 func Pr_str(obj types.MalType, print_readably bool) string {
     switch tobj := obj.(type) {
     case types.List:
-        str_list := make([]string, 0, len(tobj.Val))
-        for _, e := range tobj.Val {
-            str_list = append(str_list, Pr_str(e, print_readably))
+        return _pr_list(tobj.Val, print_readably, "(", ")")
+    case types.Vector:
+        return _pr_list(tobj.Val, print_readably, "[", "]")
+    case map[string]types.MalType:
+        str_list := make([]string, 0, len(tobj)*2)
+        for k, v := range tobj {
+            str_list = append(str_list, Pr_str(k, print_readably))
+            str_list = append(str_list, Pr_str(v, print_readably))
         }
-        return "(" + strings.Join(str_list, " ") + ")"
+        return "{" + strings.Join(str_list, " ") + "}"
     case string:
         if print_readably {
             // TODO: quote backslash, quote, and newline
@@ -31,5 +44,4 @@ func Pr_str(obj types.MalType, print_readably bool) string {
     default:
         return fmt.Sprintf("%v", obj)
     }
-    return "<printed>"
 }
diff --git a/go/src/reader/reader.go b/go/src/reader/reader.go
index 6a08840..55cea59 100644
--- a/go/src/reader/reader.go
+++ b/go/src/reader/reader.go
@@ -70,18 +70,18 @@ func read_atom(rdr Reader) (types.MalType, error) {
     return token, nil
 }
 
-func read_list(rdr Reader) (types.MalType, error) {
+func read_list(rdr Reader, start string, end string) (types.MalType, error) {
     token := rdr.next()
     if token == nil { return nil, errors.New("read_list underflow") }
 
     ast_list := []types.MalType{}
-    if *token != "(" {
-        return nil, errors.New("expected '('")
+    if *token != start {
+        return nil, errors.New("expected '" + start + "'")
     }
     token = rdr.peek()
     for ; true ; token = rdr.peek() {
-        if token == nil { return nil, errors.New("exepected ')', got EOF") }
-        if *token == ")" { break }
+        if token == nil { return nil, errors.New("exepected '" + end + "', got EOF") }
+        if *token == end { break }
         f, e := read_form(rdr)
         if e != nil { return nil, e }
         ast_list = append(ast_list, f)
@@ -90,12 +90,46 @@ func read_list(rdr Reader) (types.MalType, error) {
     return types.List{ast_list}, nil
 }
 
+func read_vector(rdr Reader) (types.MalType, error) {
+    lst, e := read_list(rdr, "[", "]")
+    if e != nil { return nil, e }
+    vec := types.Vector{lst.(types.List).Val}
+    return vec, nil
+}
+
+func read_hash_map(rdr Reader) (types.MalType, error) {
+    mal_lst, e := read_list(rdr, "{", "}")
+    lst := mal_lst.(types.List).Val
+    if e != nil { return nil, e }
+    if len(lst) % 2 == 1 {
+        return nil, errors.New("Odd number of hash map arguments")
+    }
+    m := map[string]types.MalType{}
+    for i := 0; i < len(lst); i+=2 {
+        str, ok := lst[i].(string)
+        if !ok {
+            return nil, errors.New("expected hash-map key string")
+        }
+        m[str] = lst[i+1]
+    }
+    return m, nil
+}
+
 func read_form(rdr Reader) (types.MalType, error) {
     token := rdr.peek()
     if token == nil { return nil, errors.New("read_form underflow") }
     switch (*token) {
+    // list
     case ")": return nil, errors.New("unexpected ')'")
-    case "(": return read_list(rdr)
+    case "(": return read_list(rdr, "(", ")")
+
+    // vector
+    case "]": return nil, errors.New("unexpected ']'")
+    case "[": return read_vector(rdr)
+
+    // hash-map
+    case "}": return nil, errors.New("unexpected '}'")
+    case "{": return read_hash_map(rdr)
     default:  return read_atom(rdr)
     }
     return read_atom(rdr)
diff --git a/go/src/types/types.go b/go/src/types/types.go
index 3f1c652..a212725 100644
--- a/go/src/types/types.go
+++ b/go/src/types/types.go
@@ -15,3 +15,7 @@ type List struct {
     Val []MalType
 }
 
+type Vector struct {
+    Val []MalType
+}
+