diff --git a/bootstrapping-a-language.org b/bootstrapping-a-language.org index 02c5ede..6a5b8fd 100644 --- a/bootstrapping-a-language.org +++ b/bootstrapping-a-language.org @@ -30,7 +30,7 @@ geeklisp> #+end_src * This is the true story... of several lines of code... picked to live in a REPL... to work together and have their lines executed... find out what happens when code stops being polite... and starts getting real... :slide: -* Everyone should try to write a language :slide: +* Everyone should write a language :slide: * :slide: file:lisplogo.png * Peter Norvig :slide: @@ -129,13 +129,13 @@ file:norvig.jpg #+end_src * Update eval to accept an env and repl to initialize an env :slide: #+begin_src ruby - def eval(x, env) - return env[x] if x.is_a? Symbol - return x if !x.is_a? Array - case x[0] - when :quote then x[1..-1] - when :define then env[x[1]] = eval(x[2], env) - when :set! then env.set(x[1], eval(x[2], env)) + def eval(symbol, env) + return env[symbol] if symbol.is_a? Symbol + return symbol if !symbol.is_a? Array + case symbol[0] + when :quote then symbol[1..-1] + when :define then env[symbol[1]] = eval(symbol[2], env) + when :set! then env.set(symbol[1], eval(symbol[2], env)) when :env then env end end @@ -258,18 +258,18 @@ file:norvig.jpg #+end_src * We're almost there! Let's round things out :slide: #+begin_src ruby - def eval(x, env) + def eval(symbol, env) ... when :if - _, test, conseq, alt = x + _, test, conseq, alt = symbol eval(eval(test, env) ? conseq : alt, env) when :lambda - _, vars, exp = x + _, vars, exp = symbol Proc.new{|*args| eval(exp, Env.new(vars, args, env))} when :begin - x[1..-1].reduce([nil, env]){|val_env, exp| [eval(exp, val_env[1]), val_env[1]]}[0] + symbol[1..-1].reduce([nil, env]){|val_env, exp| [eval(exp, val_env[1]), val_env[1]]}[0] else - exps = x.map{|exp| eval(exp, env)} + exps = symbol.map{|exp| eval(exp, env)} exps[0].call(*exps[1..-1]) end end diff --git a/slides.html b/slides.html index 7833422..b1901db 100644 --- a/slides.html +++ b/slides.html @@ -7,7 +7,7 @@ - + @@ -37,7 +37,7 @@

Table of Contents

  • 2 Once upon a time there was a REPL
  • 3 But that REPL didn't do much
  • 4 This is the true story… of several lines of code… picked to live in a REPL… to work together and have their lines executed… find out what happens when code stops being polite… and starts getting real…
    • -
  • 5 Everyone should try to write a language
    • +
  • 5 Everyone should write a language
  • 6 :slide:
  • 7 Peter Norvig
  • 8 The basics
    • @@ -147,7 +147,7 @@

    4 This is the true story&he
    -

    5 Everyone should try to write a language    slide

    +

    5 Everyone should write a language    slide

    @@ -343,13 +343,13 @@

    15 Update eval to accept a -
    def eval(x, env)
-  return env[x] if x.is_a? Symbol
-  return x if !x.is_a? Array
-  case x[0]
-  when :quote then x[1..-1]
-  when :define then env[x[1]] = eval(x[2], env)
-  when :set! then env.set(x[1], eval(x[2], env))
+
    def eval(symbol, env)
+  return env[symbol] if symbol.is_a? Symbol
+  return symbol if !symbol.is_a? Array
+  case symbol[0]
+  when :quote then symbol[1..-1]
+  when :define then env[symbol[1]] = eval(symbol[2], env)
+  when :set! then env.set(symbol[1], eval(symbol[2], env))
   when :env then env
   end
 end
@@ -542,18 +542,18 @@ 
    22 We're almost there! Let
 
 
 
-
    def eval(x, env)
+
    def eval(symbol, env)
   ...
   when :if
-    _, test, conseq, alt = x
+    _, test, conseq, alt = symbol
     eval(eval(test, env) ? conseq : alt, env)
   when :lambda
-    _, vars, exp = x
+    _, vars, exp = symbol
     Proc.new{|*args| eval(exp, Env.new(vars, args, env))}
   when :begin
-    x[1..-1].reduce([nil, env]){|val_env, exp| [eval(exp, val_env[1]), val_env[1]]}[0]
+    symbol[1..-1].reduce([nil, env]){|val_env, exp| [eval(exp, val_env[1]), val_env[1]]}[0]
   else
-    exps = x.map{|exp| eval(exp, env)}
+    exps = symbol.map{|exp| eval(exp, env)}
     exps[0].call(*exps[1..-1])
   end
 end
@@ -1100,7 +1100,7 @@ 
    46 References   

    -

    Date: 2012-06-27T09:06-0400

    +

    Date: 2012-06-27T11:40-0400

    Author: Aaron Bedra

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