Fix "if" again when no else position.

For JS, return null rather than undefined. For python, return null rather than error-ing out.
kanaka · Aug 15, 2024 · c64353f · c64353f
1 parent 1d2e6d0
commit c64353f
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Showing 22 changed files with 24 additions and 24 deletions.
diff --git a/index.html b/index.html
@@ -32,8 +32,8 @@ <h2>A Delightfully Diminutive Lisp</h2>
     <div class="console" id="console"></div>
     </div>
     <div class="eleven columns" style="font-family: monospace">
-      miniMAL: &nbsp;<a href="js/web/miniMAL-min.js">min</a> (&nbsp;829 bytes),
-       <a href="js/stepB_web.js">orig</a> (4081 bytes, 119 lines)<br>
+      miniMAL: &nbsp;<a href="js/web/miniMAL-min.js">min</a> (&nbsp;835 bytes),
+       <a href="js/stepB_web.js">orig</a> (4089 bytes, 119 lines)<br>
       Core Lib: <a href="js/web/miniMAL-core.js">min</a> (1086 bytes),
        <a href="js/core.json">orig</a> (4161 bytes, 120 lines)
     </div>

diff --git a/js/miniMAL-node.js b/js/miniMAL-node.js
diff --git a/js/step2_eval.js b/js/step2_eval.js
@@ -11,7 +11,7 @@ function EVAL(env, ast, f, el) {
           ? env[ast]                            // lookup symbol
           : (a => {throw ast + " not found"})() // undefined symbol
       } else {
-        return ast
+        return ast ?? null
       }
     } else {
       // apply

diff --git a/js/step3_env.js b/js/step3_env.js
@@ -11,7 +11,7 @@ function EVAL(env, ast, f, el) {
           ? env[ast]                            // lookup symbol
           : (a => {throw ast + " not found"})() // undefined symbol
       } else {
-        return ast
+        return ast ?? null
       }
     } else {
       // apply

diff --git a/js/step4_if_fn_do.js b/js/step4_if_fn_do.js
@@ -20,7 +20,7 @@ function EVAL(env, ast, f, el) {
           ? env[ast]                            // lookup symbol
           : (a => {throw ast + " not found"})() // undefined symbol
       } else {
-        return ast
+        return ast ?? null
       }
     } else {
       // apply

diff --git a/js/step5_tco.js b/js/step5_tco.js
@@ -21,7 +21,7 @@ function EVAL(env, ast, f, el) {
           ? env[ast]                            // lookup symbol
           : (a => {throw ast + " not found"})() // undefined symbol
       } else {
-        return ast
+        return ast ?? null
       }
     } else {
       // apply

diff --git a/js/step6_file.js b/js/step6_file.js
@@ -21,7 +21,7 @@ function EVAL(env, ast, f, el) {
           ? env[ast]                            // lookup symbol
           : (a => {throw ast + " not found"})() // undefined symbol
       } else {
-        return ast
+        return ast ?? null
       }
     } else {
       // apply

diff --git a/js/step7_interop.js b/js/step7_interop.js
@@ -23,7 +23,7 @@ function EVAL(env, ast, f, el) {
           ? env[ast]                            // lookup symbol
           : E.throw(ast + " not found")         // undefined symbol
       } else {
-        return ast
+        return ast ?? null
       }
     } else {
       // apply

diff --git a/js/step8_macros.js b/js/step8_macros.js
@@ -23,7 +23,7 @@ function EVAL(env, ast, f, el) {
           ? env[ast]                            // lookup symbol
           : E.throw(ast + " not found")         // undefined symbol
       } else {
-        return ast
+        return ast ?? null
       }
     } else {
       // apply

diff --git a/js/step9_try.js b/js/step9_try.js
@@ -23,7 +23,7 @@ function EVAL(env, ast, f, el) {
           ? env[ast]                            // lookup symbol
           : E.throw(ast + " not found")         // undefined symbol
       } else {
-        return ast
+        return ast ?? null
       }
     } else {
       // apply

diff --git a/js/stepA_miniMAL.js b/js/stepA_miniMAL.js
@@ -28,7 +28,7 @@ function EVAL(env, ast, f, el) {
             ? Object.keys(ast).reduce(
               (a,k) => (a[k] = EVAL(env, ast[k]), a), {}) // eval object values
             : ast                               // return ast unchanged
-          : ast
+          : ast ?? null
       }
     } else {
       // apply

diff --git a/js/stepB_node.js b/js/stepB_node.js
@@ -28,7 +28,7 @@ function EVAL(env, ast, f, el) {
             ? Object.keys(ast).reduce(
               (a,k) => (a[k] = EVAL(env, ast[k]), a), {}) // eval object values
             : ast                               // return ast unchanged
-          : ast
+          : ast ?? null
       }
     } else {
       // apply

diff --git a/js/stepB_web.js b/js/stepB_web.js
@@ -28,7 +28,7 @@ function EVAL(env, ast, f, el) {
             ? Object.keys(ast).reduce(
               (a,k) => (a[k] = EVAL(env, ast[k]), a), {}) // eval object values
             : ast                               // return ast unchanged
-          : ast
+          : ast ?? null
       }
     } else {
       // apply

diff --git a/js/web/miniMAL-min.js b/js/web/miniMAL-min.js
diff --git a/python/step4_if_fn_do.py b/python/step4_if_fn_do.py
@@ -36,7 +36,7 @@ def EVAL(ast, env):
     elif "do" == ast[0]:
         return [EVAL(a, env) for a in ast[1:]][-1]
     elif "if" == ast[0]:
-        return EVAL(ast[2] if EVAL(ast[1], env) else ast[3], env)
+        return EVAL(ast[2] if EVAL(ast[1], env) else (*ast[3:4], None)[0], env)
     elif "fn" == ast[0]:
         return lambda *a: EVAL(ast[2], Env(env, ast[1], a))
     else:

diff --git a/python/step5_tco.py b/python/step5_tco.py
@@ -38,7 +38,7 @@ def EVAL(ast, env):
         [EVAL(a, env) for a in ast[1:-1]]
         ast = ast[-1]  # TCO
     elif "if" == ast[0]:
-        ast = ast[2] if EVAL(ast[1], env) else ast[3] # TCO
+        ast = ast[2] if EVAL(ast[1], env) else (*ast[3:4], None)[0] # TCO
     elif "fn" == ast[0]:
         fn = lambda *a: EVAL(ast[2], Env(env, ast[1], [*a]))
         fn.A = [ast[2], env, ast[1]]

diff --git a/python/step6_file.py b/python/step6_file.py
@@ -40,7 +40,7 @@ def EVAL(ast, env):
         [EVAL(a, env) for a in ast[1:-1]]
         ast = ast[-1]  # TCO
     elif "if" == ast[0]:
-        ast = ast[2] if EVAL(ast[1], env) else ast[3] # TCO
+        ast = ast[2] if EVAL(ast[1], env) else (*ast[3:4], None)[0] # TCO
     elif "fn" == ast[0]:
         fn = lambda *a: EVAL(ast[2], Env(env, ast[1], [*a]))
         fn.A = [ast[2], env, ast[1]]

diff --git a/python/step7_interop.py b/python/step7_interop.py
@@ -45,7 +45,7 @@ def EVAL(ast, env):
         [EVAL(a, env) for a in ast[1:-1]]
         ast = ast[-1]  # TCO
     elif "if" == ast[0]:
-        ast = ast[2] if EVAL(ast[1], env) else ast[3] # TCO
+        ast = ast[2] if EVAL(ast[1], env) else (*ast[3:4], None)[0] # TCO
     elif "fn" == ast[0]:
         fn = lambda *a: EVAL(ast[2], Env(env, ast[1], [*a]))
         fn.A = [ast[2], env, ast[1]]

diff --git a/python/step8_macros.py b/python/step8_macros.py
@@ -49,7 +49,7 @@ def EVAL(ast, env):
         [EVAL(a, env) for a in ast[1:-1]]
         ast = ast[-1]  # TCO
     elif "if" == ast[0]:
-        ast = ast[2] if EVAL(ast[1], env) else ast[3] # TCO
+        ast = ast[2] if EVAL(ast[1], env) else (*ast[3:4], None)[0] # TCO
     elif "fn" == ast[0]:
         fn = lambda *a: EVAL(ast[2], Env(env, ast[1], [*a]))
         fn.A = [ast[2], env, ast[1]]

diff --git a/python/step9_try.py b/python/step9_try.py
@@ -54,7 +54,7 @@ def EVAL(ast, env):
         [EVAL(a, env) for a in ast[1:-1]]
         ast = ast[-1]  # TCO
     elif "if" == ast[0]:
-        ast = ast[2] if EVAL(ast[1], env) else ast[3] # TCO
+        ast = ast[2] if EVAL(ast[1], env) else (*ast[3:4], None)[0] # TCO
     elif "fn" == ast[0]:
         fn = lambda *a: EVAL(ast[2], Env(env, ast[1], [*a]))
         fn.A = [ast[2], env, ast[1]]

diff --git a/python/stepA_miniMAL.py b/python/stepA_miniMAL.py
@@ -55,7 +55,7 @@ def EVAL(ast, env):
         [EVAL(a, env) for a in ast[1:-1]]
         ast = ast[-1]  # TCO
     elif "if" == ast[0]:
-        ast = ast[2] if EVAL(ast[1], env) else ast[3] # TCO
+        ast = ast[2] if EVAL(ast[1], env) else (*ast[3:4], None)[0] # TCO
     elif "fn" == ast[0]:
         fn = lambda *a: EVAL(ast[2], Env(env, ast[1], [*a]))
         fn.A = [ast[2], env, ast[1]]

diff --git a/tests/step4_if_fn_do.json b/tests/step4_if_fn_do.json
@@ -29,8 +29,8 @@
 ;=>false
 ["if", null, 8, 7]
 ;=>7
-["if", null, 8]
-;=>undefined
+["if", false, 8]
+;=>null
 
 
 ;; Testing basic conditionals