add input function

stdlib/stdlib.go

@@ -20,34 +20,42 @@ package stdlib
 import (
     "os"
     "fmt"
+    "gitlab.com/whom/shs/log"
     "gitlab.com/whom/shs/ast"
 )
 
 func GenFuncTable() ast.FuncTable {
     var stdlib ast.FuncTable
     stdlib = &map[string]*ast.Function{
-      "if": &ast.Function{
+        "if": &ast.Function{
             Function: shs_if,
             Name:       "if",
             TimesCalled:   0,
             Args:          3,
         },
 
-      "while": &ast.Function{
+        "while": &ast.Function{
             Function: shs_while,
             Name:       "while",
             TimesCalled:      0,
             Args:            -1,
         },
 
-      "eval": &ast.Function{
+        "eval": &ast.Function{
             Function:   eval,
             Name:     "eval",
             TimesCalled:   0,
             Args:         -1,
         },
 
-       "...": &ast.Function{
+        "input": &ast.Function{
+            Function:  input,
+            Name:    "input",
+            TimesCalled:   0,
+            Args:          1,
+        },
+
+        "...": &ast.Function{
             Function: expand,
             Name:      "...",
             TimesCalled:   0,
@@ -267,3 +275,23 @@ func sh_info(in *ast.Token, vt ast.VarTable, ft ast.FuncTable) *ast.Token {
 func eval(in *ast.Token, vt ast.VarTable, ft ast.FuncTable) *ast.Token {
     return in.Eval(ft, vt, false)
 }
+
+func input(in *ast.Token, vt ast.VarTable, ft ast.FuncTable) *ast.Token {
+    in = in.Eval(ft, vt, false)
+    if in.Tag != ast.STRING && in.Tag != ast.NUMBER {
+        log.Log(log.ERR,
+            "argument to input must be a string or number",
+            "input")
+        return nil
+    }
+
+    prompt := in.Value()
+    var output string
+
+    fmt.Printf(prompt)
+    fmt.Scanln(&output)
+
+    ret := &ast.Token{Tag: ast.STRING}
+    ret.Set(output)
+    return ret
+}