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<span class="Comment">//: Structured programming</span>
<span class="Comment">//:</span>
<span class="Comment">//: Our jump recipes are quite inconvenient to use, so mu provides a</span>
<span class="Comment">//: lightweight tool called 'transform_braces' to work in a slightly more</span>
<span class="Comment">//: convenient format with nested braces:</span>
<span class="Comment">//:</span>
<span class="Comment">//: {</span>
<span class="Comment">//: some instructions</span>
<span class="Comment">//: {</span>
<span class="Comment">//: more instructions</span>
<span class="Comment">//: }</span>
<span class="Comment">//: }</span>
<span class="Comment">//:</span>
<span class="Comment">//: Braces are just labels, they require no special parsing. The pseudo</span>
<span class="Comment">//: recipes 'loop' and 'break' jump to just after the enclosing '{' and '}'</span>
<span class="Comment">//: respectively.</span>
<span class="Comment">//:</span>
<span class="Comment">//: Conditional and unconditional 'loop' and 'break' should give us 80% of the</span>
<span class="Comment">//: benefits of the control-flow primitives we're used to in other languages,</span>
<span class="Comment">//: like 'if', 'while', 'for', etc.</span>
<span class="Delimiter">:(scenarios transform)</span>
<span class="Delimiter">:(scenario brace_conversion)</span>
def main [
<span class="Delimiter">{</span>
<span class="Identifier">break</span>
<span class="Constant">1</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">}</span>
]
<span class="traceContains">+transform: --- transform braces for recipe main</span>
<span class="traceContains">+transform: jump 1:offset</span>
<span class="traceContains">+transform: copy ...</span>
<span class="Delimiter">:(before "End Instruction Modifying Transforms")</span>
Transform<span class="Delimiter">.</span>push_back<span class="Delimiter">(</span>transform_braces<span class="Delimiter">);</span> <span class="Comment">// idempotent</span>
<span class="Delimiter">:(code)</span>
<span class="Normal">void</span> transform_braces<span class="Delimiter">(</span><span class="Normal">const</span> recipe_ordinal r<span class="Delimiter">)</span> <span class="Delimiter">{</span>
<span class="Normal">const</span> <span class="Normal">int</span> OPEN = <span class="Constant">0</span><span class="Delimiter">,</span> CLOSE = <span class="Constant">1</span><span class="Delimiter">;</span>
<span class="Comment">// use signed integer for step index because we'll be doing arithmetic on it</span>
list<pair<<span class="Normal">int</span><span class="Comment">/*</span><span class="Comment">OPEN/CLOSE</span><span class="Comment">*/</span><span class="Delimiter">,</span> <span class="Comment">/*</span><span class="Comment">step</span><span class="Comment">*/</span><span class="Normal">int</span>> > braces<span class="Delimiter">;</span>
trace<span class="Delimiter">(</span><span class="Constant">9991</span><span class="Delimiter">,</span> <span class="Constant">"transform"</span><span class="Delimiter">)</span> << <span class="Constant">"--- transform braces for recipe "</span> << get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>name << end<span class="Delimiter">();</span>
<span class="CommentedCode">//? cerr << "--- transform braces for recipe " << get(Recipe, r).name << '\n';</span>
<span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">int</span> index = <span class="Constant">0</span><span class="Delimiter">;</span> index < SIZE<span class="Delimiter">(</span>get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>steps<span class="Delimiter">);</span> ++index<span class="Delimiter">)</span> <span class="Delimiter">{</span>
<span class="Normal">const</span> instruction& inst = get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>steps<span class="Delimiter">.</span>at<span class="Delimiter">(</span>index<span class="Delimiter">);</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>inst<span class="Delimiter">.</span>label == <span class="Constant">"{"</span><span class="Delimiter">)</span> <span class="Delimiter">{</span>
trace<span class="Delimiter">(</span><span class="Constant">9993</span><span class="Delimiter">,</span> <span class="Constant">"transform"</span><span class="Delimiter">)</span> << maybe<span class="Delimiter">(</span>get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>name<span class="Delimiter">)</span> << <span class="Constant">"push (open, "</span> << index << <span class="Constant">")"</span> << end<span class="Delimiter">();</span>
braces<span class="Delimiter">.</span>push_back<span class="Delimiter">(</span>pair<<span class="Normal">int</span><span class="Delimiter">,</span><span class="Normal">int</span>><span class="Delimiter">(</span>OPEN<span class="Delimiter">,</span> index<span class="Delimiter">));</span>
<span class="Delimiter">}</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>inst<span class="Delimiter">.</span>label == <span class="Constant">"}"</span><span class="Delimiter">)</span> <span class="Delimiter">{</span>
trace<span class="Delimiter">(</span><span class="Constant">9993</span><span class="Delimiter">,</span> <span class="Constant">"transform"</span><span class="Delimiter">)</span> << <span class="Constant">"push (close, "</span> << index << <span class="Constant">")"</span> << end<span class="Delimiter">();</span>
braces<span class="Delimiter">.</span>push_back<span class="Delimiter">(</span>pair<<span class="Normal">int</span><span class="Delimiter">,</span><span class="Normal">int</span>><span class="Delimiter">(</span>CLOSE<span class="Delimiter">,</span> index<span class="Delimiter">));</span>
<span class="Delimiter">}</span>
<span class="Delimiter">}</span>
stack<<span class="Comment">/*</span><span class="Comment">step</span><span class="Comment">*/</span><span class="Normal">int</span>> open_braces<span class="Delimiter">;</span>
<span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">int</span> index = <span class="Constant">0</span><span class="Delimiter">;</span> index < SIZE<span class="Delimiter">(</span>get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>steps<span class="Delimiter">);</span> ++index<span class="Delimiter">)</span> <span class="Delimiter">{</span>
instruction& inst = get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>steps<span class="Delimiter">.</span>at<span class="Delimiter">(</span>index<span class="Delimiter">);</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>inst<span class="Delimiter">.</span>label == <span class="Constant">"{"</span><span class="Delimiter">)</span> <span class="Delimiter">{</span>
open_braces<span class="Delimiter">.</span>push<span class="Delimiter">(</span>index<span class="Delimiter">);</span>
<span class="Identifier">continue</span><span class="Delimiter">;</span>
<span class="Delimiter">}</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>inst<span class="Delimiter">.</span>label == <span class="Constant">"}"</span><span class="Delimiter">)</span> <span class="Delimiter">{</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>open_braces<span class="Delimiter">.</span>empty<span class="Delimiter">())</span> <span class="Delimiter">{</span>
raise << <span class="Constant">"missing '{' in '"</span> << get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>name << <span class="Constant">"'</span><span class="cSpecial">\n</span><span class="Constant">"</span> << end<span class="Delimiter">();</span>
<span class="Identifier">return</span><span class="Delimiter">;</span>
<span class="Delimiter">}</span>
open_braces<span class="Delimiter">.</span>pop<span class="Delimiter">();</span>
<span class="Identifier">continue</span><span class="Delimiter">;</span>
<span class="Delimiter">}</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>inst<span class="Delimiter">.</span>is_label<span class="Delimiter">)</span> <span class="Identifier">continue</span><span class="Delimiter">;</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>inst<span class="Delimiter">.</span>old_name != <span class="Constant">"loop"</span>
&& inst<span class="Delimiter">.</span>old_name != <span class="Constant">"loop-if"</span>
&& inst<span class="Delimiter">.</span>old_name != <span class="Constant">"loop-unless"</span>
&& inst<span class="Delimiter">.</span>old_name != <span class="Constant">"break"</span>
&& inst<span class="Delimiter">.</span>old_name != <span class="Constant">"break-if"</span>
&& inst<span class="Delimiter">.</span>old_name != <span class="Constant">"break-unless"</span><span class="Delimiter">)</span> <span class="Delimiter">{</span>
trace<span class="Delimiter">(</span><span class="Constant">9992</span><span class="Delimiter">,</span> <span class="Constant">"transform"</span><span class="Delimiter">)</span> << inst<span class="Delimiter">.</span>old_name << <span class="Constant">" ..."</span> << end<span class="Delimiter">();</span>
<span class="Identifier">continue</span><span class="Delimiter">;</span>
<span class="Delimiter">}</span>
<span class="Comment">// check for errors</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>inst<span class="Delimiter">.</span>old_name<span class="Delimiter">.</span>find<span class="Delimiter">(</span><span class="Constant">"-if"</span><span class="Delimiter">)</span> != string::npos || inst<span class="Delimiter">.</span>old_name<span class="Delimiter">.</span>find<span class="Delimiter">(</span><span class="Constant">"-unless"</span><span class="Delimiter">)</span> != string::npos<span class="Delimiter">)</span> <span class="Delimiter">{</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>empty<span class="Delimiter">())</span> <span class="Delimiter">{</span>
raise << <span class="Constant">"'"</span> << inst<span class="Delimiter">.</span>old_name << <span class="Constant">"' expects 1 or 2 ingredients, but got none</span><span class="cSpecial">\n</span><span class="Constant">"</span> << end<span class="Delimiter">();</span>
<span class="Identifier">continue</span><span class="Delimiter">;</span>
<span class="Delimiter">}</span>
<span class="Delimiter">}</span>
<span class="Comment">// update instruction operation</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>inst<span class="Delimiter">.</span>old_name<span class="Delimiter">.</span>find<span class="Delimiter">(</span><span class="Constant">"-if"</span><span class="Delimiter">)</span> != string::npos<span class="Delimiter">)</span> <span class="Delimiter">{</span>
inst<span class="Delimiter">.</span>name = <span class="Constant">"jump-if"</span><span class="Delimiter">;</span>
inst<span class="Delimiter">.</span>operation = JUMP_IF<span class="Delimiter">;</span>
<span class="Delimiter">}</span>
<span class="Normal">else</span> <span class="Normal">if</span> <span class="Delimiter">(</span>inst<span class="Delimiter">.</span>old_name<span class="Delimiter">.</span>find<span class="Delimiter">(</span><span class="Constant">"-unless"</span><span class="Delimiter">)</span> != string::npos<span class="Delimiter">)</span> <span class="Delimiter">{</span>
inst<span class="Delimiter">.</span>name = <span class="Constant">"jump-unless"</span><span class="Delimiter">;</span>
inst<span class="Delimiter">.</span>operation = JUMP_UNLESS<span class="Delimiter">;</span>
<span class="Delimiter">}</span>
<span class="Normal">else</span> <span class="Delimiter">{</span>
inst<span class="Delimiter">.</span>name = <span class="Constant">"jump"</span><span class="Delimiter">;</span>
inst<span class="Delimiter">.</span>operation = JUMP<span class="Delimiter">;</span>
<span class="Delimiter">}</span>
<span class="Comment">// check for explicitly provided targets</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>inst<span class="Delimiter">.</span>old_name<span class="Delimiter">.</span>find<span class="Delimiter">(</span><span class="Constant">"-if"</span><span class="Delimiter">)</span> != string::npos || inst<span class="Delimiter">.</span>old_name<span class="Delimiter">.</span>find<span class="Delimiter">(</span><span class="Constant">"-unless"</span><span class="Delimiter">)</span> != string::npos<span class="Delimiter">)</span> <span class="Delimiter">{</span>
<span class="Comment">// conditional branches check arg 1</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>SIZE<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">)</span> > <span class="Constant">1</span> && is_literal<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">1</span><span class="Delimiter">)))</span> <span class="Delimiter">{</span>
trace<span class="Delimiter">(</span><span class="Constant">9992</span><span class="Delimiter">,</span> <span class="Constant">"transform"</span><span class="Delimiter">)</span> << inst<span class="Delimiter">.</span>name << <span class="Constant">' '</span> << inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">1</span><span class="Delimiter">).</span>name << <span class="Constant">":offset"</span> << end<span class="Delimiter">();</span>
<span class="Identifier">continue</span><span class="Delimiter">;</span>
<span class="Delimiter">}</span>
<span class="Delimiter">}</span>
<span class="Normal">else</span> <span class="Delimiter">{</span>
<span class="Comment">// unconditional branches check arg 0</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>!inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>empty<span class="Delimiter">()</span> && is_literal<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">)))</span> <span class="Delimiter">{</span>
trace<span class="Delimiter">(</span><span class="Constant">9992</span><span class="Delimiter">,</span> <span class="Constant">"transform"</span><span class="Delimiter">)</span> << <span class="Constant">"jump "</span> << inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">).</span>name << <span class="Constant">":offset"</span> << end<span class="Delimiter">();</span>
<span class="Identifier">continue</span><span class="Delimiter">;</span>
<span class="Delimiter">}</span>
<span class="Delimiter">}</span>
<span class="Comment">// if implicit, compute target</span>
reagent target<span class="Delimiter">;</span>
target<span class="Delimiter">.</span>type = <span class="Normal">new</span> type_tree<span class="Delimiter">(</span><span class="Constant">"offset"</span><span class="Delimiter">);</span>
target<span class="Delimiter">.</span>set_value<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">);</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>open_braces<span class="Delimiter">.</span>empty<span class="Delimiter">())</span>
raise << <span class="Constant">"'"</span> << inst<span class="Delimiter">.</span>old_name << <span class="Constant">"' needs a '{' before</span><span class="cSpecial">\n</span><span class="Constant">"</span> << end<span class="Delimiter">();</span>
<span class="Normal">else</span> <span class="Normal">if</span> <span class="Delimiter">(</span>inst<span class="Delimiter">.</span>old_name<span class="Delimiter">.</span>find<span class="Delimiter">(</span><span class="Constant">"loop"</span><span class="Delimiter">)</span> != string::npos<span class="Delimiter">)</span>
target<span class="Delimiter">.</span>set_value<span class="Delimiter">(</span>open_braces<span class="Delimiter">.</span>top<span class="Delimiter">()</span>-index<span class="Delimiter">);</span>
<span class="Normal">else</span> <span class="Comment">// break instruction</span>
target<span class="Delimiter">.</span>set_value<span class="Delimiter">(</span>matching_brace<span class="Delimiter">(</span>open_braces<span class="Delimiter">.</span>top<span class="Delimiter">(),</span> braces<span class="Delimiter">,</span> r<span class="Delimiter">)</span> - index - <span class="Constant">1</span><span class="Delimiter">);</span>
inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>push_back<span class="Delimiter">(</span>target<span class="Delimiter">);</span>
<span class="Comment">// log computed target</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>inst<span class="Delimiter">.</span>name == <span class="Constant">"jump"</span><span class="Delimiter">)</span>
trace<span class="Delimiter">(</span><span class="Constant">9992</span><span class="Delimiter">,</span> <span class="Constant">"transform"</span><span class="Delimiter">)</span> << <span class="Constant">"jump "</span> << no_scientific<span class="Delimiter">(</span>target<span class="Delimiter">.</span>value<span class="Delimiter">)</span> << <span class="Constant">":offset"</span> << end<span class="Delimiter">();</span>
<span class="Normal">else</span>
trace<span class="Delimiter">(</span><span class="Constant">9992</span><span class="Delimiter">,</span> <span class="Constant">"transform"</span><span class="Delimiter">)</span> << inst<span class="Delimiter">.</span>name << <span class="Constant">' '</span> << inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">).</span>name << <span class="Constant">", "</span> << no_scientific<span class="Delimiter">(</span>target<span class="Delimiter">.</span>value<span class="Delimiter">)</span> << <span class="Constant">":offset"</span> << end<span class="Delimiter">();</span>
<span class="Delimiter">}</span>
<span class="Delimiter">}</span>
<span class="Comment">// returns a signed integer not just so that we can return -1 but also to</span>
<span class="Comment">// enable future signed arithmetic</span>
<span class="Normal">int</span> matching_brace<span class="Delimiter">(</span><span class="Normal">int</span> index<span class="Delimiter">,</span> <span class="Normal">const</span> list<pair<<span class="Normal">int</span><span class="Delimiter">,</span> <span class="Normal">int</span>> >& braces<span class="Delimiter">,</span> recipe_ordinal r<span class="Delimiter">)</span> <span class="Delimiter">{</span>
<span class="Normal">int</span> stacksize = <span class="Constant">0</span><span class="Delimiter">;</span>
<span class="Normal">for</span> <span class="Delimiter">(</span>list<pair<<span class="Normal">int</span><span class="Delimiter">,</span> <span class="Normal">int</span>> >::const_iterator p = braces<span class="Delimiter">.</span>begin<span class="Delimiter">();</span> p != braces<span class="Delimiter">.</span>end<span class="Delimiter">();</span> ++p<span class="Delimiter">)</span> <span class="Delimiter">{</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>p<span class="Delimiter">-></span>second < index<span class="Delimiter">)</span> <span class="Identifier">continue</span><span class="Delimiter">;</span>
stacksize += <span class="Delimiter">(</span>p<span class="Delimiter">-></span>first ? <span class="Constant">1</span> : -<span class="Constant">1</span><span class="Delimiter">);</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>stacksize == <span class="Constant">0</span><span class="Delimiter">)</span> <span class="Identifier">return</span> p<span class="Delimiter">-></span>second<span class="Delimiter">;</span>
<span class="Delimiter">}</span>
raise << maybe<span class="Delimiter">(</span>get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>name<span class="Delimiter">)</span> << <span class="Constant">"unbalanced '{'</span><span class="cSpecial">\n</span><span class="Constant">"</span> << end<span class="Delimiter">();</span>
<span class="Identifier">return</span> SIZE<span class="Delimiter">(</span>get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>steps<span class="Delimiter">);</span> <span class="Comment">// exit current routine</span>
<span class="Delimiter">}</span>
<span class="Delimiter">:(scenario loop)</span>
def main [
<span class="Constant">1</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Constant">2</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">{</span>
<span class="Constant">3</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
loop
<span class="Delimiter">}</span>
]
<span class="traceContains">+transform: --- transform braces for recipe main</span>
<span class="traceContains">+transform: copy ...</span>
<span class="traceContains">+transform: copy ...</span>
<span class="traceContains">+transform: copy ...</span>
<span class="traceContains">+transform: jump -2:offset</span>
<span class="Delimiter">:(scenario break_empty_block)</span>
def main [
<span class="Constant">1</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">{</span>
<span class="Identifier">break</span>
<span class="Delimiter">}</span>
]
<span class="traceContains">+transform: --- transform braces for recipe main</span>
<span class="traceContains">+transform: copy ...</span>
<span class="traceContains">+transform: jump 0:offset</span>
<span class="Delimiter">:(scenario break_cascading)</span>
def main [
<span class="Constant">1</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">{</span>
<span class="Identifier">break</span>
<span class="Delimiter">}</span>
<span class="Delimiter">{</span>
<span class="Identifier">break</span>
<span class="Delimiter">}</span>
]
<span class="traceContains">+transform: --- transform braces for recipe main</span>
<span class="traceContains">+transform: copy ...</span>
<span class="traceContains">+transform: jump 0:offset</span>
<span class="traceContains">+transform: jump 0:offset</span>
<span class="Delimiter">:(scenario break_cascading_2)</span>
def main [
<span class="Constant">1</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Constant">2</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">{</span>
<span class="Identifier">break</span>
<span class="Constant">3</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">}</span>
<span class="Delimiter">{</span>
<span class="Identifier">break</span>
<span class="Delimiter">}</span>
]
<span class="traceContains">+transform: --- transform braces for recipe main</span>
<span class="traceContains">+transform: copy ...</span>
<span class="traceContains">+transform: copy ...</span>
<span class="traceContains">+transform: jump 1:offset</span>
<span class="traceContains">+transform: copy ...</span>
<span class="traceContains">+transform: jump 0:offset</span>
<span class="Delimiter">:(scenario break_if)</span>
def main [
<span class="Constant">1</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Constant">2</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">{</span>
<span class="Identifier">break</span>-<span class="Normal">if</span> <span class="Constant">2</span>:number
<span class="Constant">3</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">}</span>
<span class="Delimiter">{</span>
<span class="Identifier">break</span>
<span class="Delimiter">}</span>
]
<span class="traceContains">+transform: --- transform braces for recipe main</span>
<span class="traceContains">+transform: copy ...</span>
<span class="traceContains">+transform: copy ...</span>
<span class="traceContains">+transform: jump-if 2, 1:offset</span>
<span class="traceContains">+transform: copy ...</span>
<span class="traceContains">+transform: jump 0:offset</span>
<span class="Delimiter">:(scenario break_nested)</span>
def main [
<span class="Constant">1</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">{</span>
<span class="Constant">2</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Identifier">break</span>
<span class="Delimiter">{</span>
<span class="Constant">3</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">}</span>
<span class="Constant">4</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">}</span>
]
<span class="traceContains">+transform: jump 4:offset</span>
<span class="Delimiter">:(scenario break_nested_degenerate)</span>
def main [
<span class="Constant">1</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">{</span>
<span class="Constant">2</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Identifier">break</span>
<span class="Delimiter">{</span>
<span class="Delimiter">}</span>
<span class="Constant">4</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">}</span>
]
<span class="traceContains">+transform: jump 3:offset</span>
<span class="Delimiter">:(scenario break_nested_degenerate_2)</span>
def main [
<span class="Constant">1</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">{</span>
<span class="Constant">2</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Identifier">break</span>
<span class="Delimiter">{</span>
<span class="Delimiter">}</span>
<span class="Delimiter">}</span>
]
<span class="traceContains">+transform: jump 2:offset</span>
<span class="Delimiter">:(scenario break_label)</span>
<span class="Special">% Hide_errors = true;</span>
def main [
<span class="Constant">1</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">{</span>
<span class="Identifier">break</span> +foo:offset
<span class="Delimiter">}</span>
]
<span class="traceContains">+transform: jump +foo:offset</span>
<span class="Delimiter">:(scenario break_unless)</span>
def main [
<span class="Constant">1</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Constant">2</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">{</span>
<span class="Identifier">break</span>-unless <span class="Constant">2</span>:number
<span class="Constant">3</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">}</span>
]
<span class="traceContains">+transform: --- transform braces for recipe main</span>
<span class="traceContains">+transform: copy ...</span>
<span class="traceContains">+transform: copy ...</span>
<span class="traceContains">+transform: jump-unless 2, 1:offset</span>
<span class="traceContains">+transform: copy ...</span>
<span class="Delimiter">:(scenario loop_unless)</span>
def main [
<span class="Constant">1</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Constant">2</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">{</span>
loop-unless <span class="Constant">2</span>:number
<span class="Constant">3</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">}</span>
]
<span class="traceContains">+transform: --- transform braces for recipe main</span>
<span class="traceContains">+transform: copy ...</span>
<span class="traceContains">+transform: copy ...</span>
<span class="traceContains">+transform: jump-unless 2, -1:offset</span>
<span class="traceContains">+transform: copy ...</span>
<span class="Delimiter">:(scenario loop_nested)</span>
def main [
<span class="Constant">1</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">{</span>
<span class="Constant">2</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">{</span>
<span class="Constant">3</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">}</span>
loop-<span class="Normal">if</span> <span class="Constant">4</span>:boolean
<span class="Constant">5</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
<span class="Delimiter">}</span>
]
<span class="traceContains">+transform: --- transform braces for recipe main</span>
<span class="traceContains">+transform: jump-if 4, -5:offset</span>
<span class="Delimiter">:(scenario loop_label)</span>
def main [
<span class="Constant">1</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
+foo
<span class="Constant">2</span>:number<span class="Special"> <- </span>copy <span class="Constant">0</span>
]
<span class="traceContains">+transform: --- transform braces for recipe main</span>
<span class="traceContains">+transform: copy ...</span>
<span class="traceContains">+transform: copy ...</span>
<span class="Comment">//: test how things actually run</span>
<span class="Delimiter">:(scenarios run)</span>
<span class="Delimiter">:(scenario brace_conversion_and_run)</span>
def test-factorial [
<span class="Constant">1</span>:number<span class="Special"> <- </span>copy <span class="Constant">5</span>
<span class="Constant">2</span>:number<span class="Special"> <- </span>copy <span class="Constant">1</span>
<span class="Delimiter">{</span>
<span class="Constant">3</span>:boolean<span class="Special"> <- </span>equal <span class="Constant">1</span>:number<span class="Delimiter">,</span> <span class="Constant">1</span>
<span class="Identifier">break</span>-<span class="Normal">if</span> <span class="Constant">3</span>:boolean
<span class="Comment"># $print 1:number</span>
<span class="Constant">2</span>:number<span class="Special"> <- </span>multiply <span class="Constant">2</span>:number<span class="Delimiter">,</span> <span class="Constant">1</span>:number
<span class="Constant">1</span>:number<span class="Special"> <- </span>subtract <span class="Constant">1</span>:number<span class="Delimiter">,</span> <span class="Constant">1</span>
loop
<span class="Delimiter">}</span>
<span class="Constant">4</span>:number<span class="Special"> <- </span>copy <span class="Constant">2</span>:number <span class="Comment"># trigger a read</span>
]
<span class="traceContains">+mem: location 2 is 120</span>
<span class="Delimiter">:(scenario break_outside_braces_fails)</span>
<span class="Special">% Hide_errors = true;</span>
def main [
<span class="Identifier">break</span>
]
<span class="traceContains">+error: 'break' needs a '{' before</span>
<span class="Delimiter">:(scenario break_conditional_without_ingredient_fails)</span>
<span class="Special">% Hide_errors = true;</span>
def main [
<span class="Delimiter">{</span>
<span class="Identifier">break</span>-<span class="Normal">if</span>
<span class="Delimiter">}</span>
]
<span class="traceContains">+error: 'break-if' expects 1 or 2 ingredients, but got none</span>
<span class="Comment">//: Using break we can now implement conditional returns.</span>
<span class="Delimiter">:(scenario return_if)</span>
def main [
<span class="Constant">1</span>:number<span class="Special"> <- </span>test1
]
def test1 [
<span class="Identifier">return</span>-<span class="Normal">if</span> <span class="Constant">0</span><span class="Delimiter">,</span> <span class="Constant">34</span>
<span class="Identifier">return</span> <span class="Constant">35</span>
]
<span class="traceContains">+mem: storing 35 in location 1</span>
<span class="Delimiter">:(scenario return_if_2)</span>
def main [
<span class="Constant">1</span>:number<span class="Special"> <- </span>test1
]
def test1 [
<span class="Identifier">return</span>-<span class="Normal">if</span> <span class="Constant">1</span><span class="Delimiter">,</span> <span class="Constant">34</span>
<span class="Identifier">return</span> <span class="Constant">35</span>
]
<span class="traceContains">+mem: storing 34 in location 1</span>
<span class="Delimiter">:(before "End Rewrite Instruction(curr, recipe result)")</span>
<span class="Comment">// rewrite `return-if a, b, c, ...` to</span>
<span class="Comment">// ```</span>
<span class="Comment">// {</span>
<span class="Comment">// break-unless a</span>
<span class="Comment">// return b, c, ...</span>
<span class="Comment">// }</span>
<span class="Comment">// ```</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>curr<span class="Delimiter">.</span>name == <span class="Constant">"return-if"</span> || curr<span class="Delimiter">.</span>name == <span class="Constant">"reply-if"</span><span class="Delimiter">)</span> <span class="Delimiter">{</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>curr<span class="Delimiter">.</span>products<span class="Delimiter">.</span>empty<span class="Delimiter">())</span> <span class="Delimiter">{</span>
emit_return_block<span class="Delimiter">(</span>result<span class="Delimiter">,</span> <span class="Constant">"break-unless"</span><span class="Delimiter">,</span> curr<span class="Delimiter">.</span>ingredients<span class="Delimiter">);</span>
curr<span class="Delimiter">.</span>clear<span class="Delimiter">();</span>
<span class="Delimiter">}</span>
<span class="Normal">else</span> <span class="Delimiter">{</span>
raise << <span class="Constant">"'"</span> << curr<span class="Delimiter">.</span>name << <span class="Constant">"' never yields any products</span><span class="cSpecial">\n</span><span class="Constant">"</span> << end<span class="Delimiter">();</span>
<span class="Delimiter">}</span>
<span class="Delimiter">}</span>
<span class="Comment">// rewrite `return-unless a, b, c, ...` to</span>
<span class="Comment">// ```</span>
<span class="Comment">// {</span>
<span class="Comment">// break-if a</span>
<span class="Comment">// return b, c, ...</span>
<span class="Comment">// }</span>
<span class="Comment">// ```</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>curr<span class="Delimiter">.</span>name == <span class="Constant">"return-unless"</span> || curr<span class="Delimiter">.</span>name == <span class="Constant">"reply-unless"</span><span class="Delimiter">)</span> <span class="Delimiter">{</span>
<span class="Normal">if</span> <span class="Delimiter">(</span>curr<span class="Delimiter">.</span>products<span class="Delimiter">.</span>empty<span class="Delimiter">())</span> <span class="Delimiter">{</span>
emit_return_block<span class="Delimiter">(</span>result<span class="Delimiter">,</span> <span class="Constant">"break-if"</span><span class="Delimiter">,</span> curr<span class="Delimiter">.</span>ingredients<span class="Delimiter">);</span>
curr<span class="Delimiter">.</span>clear<span class="Delimiter">();</span>
<span class="Delimiter">}</span>
<span class="Normal">else</span> <span class="Delimiter">{</span>
raise << <span class="Constant">"'"</span> << curr<span class="Delimiter">.</span>name << <span class="Constant">"' never yields any products</span><span class="cSpecial">\n</span><span class="Constant">"</span> << end<span class="Delimiter">();</span>
<span class="Delimiter">}</span>
<span class="Delimiter">}</span>
<span class="Delimiter">:(code)</span>
<span class="Normal">void</span> emit_return_block<span class="Delimiter">(</span>recipe& out<span class="Delimiter">,</span> <span class="Normal">const</span> string& break_command<span class="Delimiter">,</span> <span class="Normal">const</span> vector<reagent>& ingredients<span class="Delimiter">)</span> <span class="Delimiter">{</span>
reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> condition = ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">);</span>
vector<reagent> return_ingredients<span class="Delimiter">;</span>
copy<span class="Delimiter">(</span>++ingredients<span class="Delimiter">.</span>begin<span class="Delimiter">(),</span> ingredients<span class="Delimiter">.</span>end<span class="Delimiter">(),</span> inserter<span class="Delimiter">(</span>return_ingredients<span class="Delimiter">,</span> return_ingredients<span class="Delimiter">.</span>end<span class="Delimiter">()));</span>
<span class="Comment">// {</span>
instruction open_label<span class="Delimiter">;</span> open_label<span class="Delimiter">.</span>is_label=<span class="Constant">true</span><span class="Delimiter">;</span> open_label<span class="Delimiter">.</span>label = <span class="Constant">"{"</span><span class="Delimiter">;</span>
out<span class="Delimiter">.</span>steps<span class="Delimiter">.</span>push_back<span class="Delimiter">(</span>open_label<span class="Delimiter">);</span>
<span class="Comment">// <break command> <condition></span>
instruction break_inst<span class="Delimiter">;</span>
break_inst<span class="Delimiter">.</span>operation = get<span class="Delimiter">(</span>Recipe_ordinal<span class="Delimiter">,</span> break_command<span class="Delimiter">);</span>
break_inst<span class="Delimiter">.</span>name = break_inst<span class="Delimiter">.</span>old_name = break_command<span class="Delimiter">;</span>
break_inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>push_back<span class="Delimiter">(</span>condition<span class="Delimiter">);</span>
out<span class="Delimiter">.</span>steps<span class="Delimiter">.</span>push_back<span class="Delimiter">(</span>break_inst<span class="Delimiter">);</span>
<span class="Comment">// return <return ingredients></span>
instruction return_inst<span class="Delimiter">;</span>
return_inst<span class="Delimiter">.</span>operation = get<span class="Delimiter">(</span>Recipe_ordinal<span class="Delimiter">,</span> <span class="Constant">"return"</span><span class="Delimiter">);</span>
return_inst<span class="Delimiter">.</span>name = <span class="Constant">"return"</span><span class="Delimiter">;</span>
return_inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>swap<span class="Delimiter">(</span>return_ingredients<span class="Delimiter">);</span>
out<span class="Delimiter">.</span>steps<span class="Delimiter">.</span>push_back<span class="Delimiter">(</span>return_inst<span class="Delimiter">);</span>
<span class="Comment">// }</span>
instruction close_label<span class="Delimiter">;</span> close_label<span class="Delimiter">.</span>is_label=<span class="Constant">true</span><span class="Delimiter">;</span> close_label<span class="Delimiter">.</span>label = <span class="Constant">"}"</span><span class="Delimiter">;</span>
out<span class="Delimiter">.</span>steps<span class="Delimiter">.</span>push_back<span class="Delimiter">(</span>close_label<span class="Delimiter">);</span>
<span class="Delimiter">}</span>
<span class="Comment">//: Make sure these pseudo recipes get consistent numbers in all tests, even</span>
<span class="Comment">//: though they aren't implemented. Allows greater flexibility in ordering</span>
<span class="Comment">//: transforms.</span>
<span class="Delimiter">:(before "End Primitive Recipe Declarations")</span>
BREAK<span class="Delimiter">,</span>
BREAK_IF<span class="Delimiter">,</span>
BREAK_UNLESS<span class="Delimiter">,</span>
LOOP<span class="Delimiter">,</span>
LOOP_IF<span class="Delimiter">,</span>
LOOP_UNLESS<span class="Delimiter">,</span>
<span class="Delimiter">:(before "End Primitive Recipe Numbers")</span>
put<span class="Delimiter">(</span>Recipe_ordinal<span class="Delimiter">,</span> <span class="Constant">"break"</span><span class="Delimiter">,</span> BREAK<span class="Delimiter">);</span>
put<span class="Delimiter">(</span>Recipe_ordinal<span class="Delimiter">,</span> <span class="Constant">"break-if"</span><span class="Delimiter">,</span> BREAK_IF<span class="Delimiter">);</span>
put<span class="Delimiter">(</span>Recipe_ordinal<span class="Delimiter">,</span> <span class="Constant">"break-unless"</span><span class="Delimiter">,</span> BREAK_UNLESS<span class="Delimiter">);</span>
put<span class="Delimiter">(</span>Recipe_ordinal<span class="Delimiter">,</span> <span class="Constant">"loop"</span><span class="Delimiter">,</span> LOOP<span class="Delimiter">);</span>
put<span class="Delimiter">(</span>Recipe_ordinal<span class="Delimiter">,</span> <span class="Constant">"loop-if"</span><span class="Delimiter">,</span> LOOP_IF<span class="Delimiter">);</span>
put<span class="Delimiter">(</span>Recipe_ordinal<span class="Delimiter">,</span> <span class="Constant">"loop-unless"</span><span class="Delimiter">,</span> LOOP_UNLESS<span class="Delimiter">);</span>
<span class="Delimiter">:(before "End Primitive Recipe Checks")</span>
<span class="Normal">case</span> BREAK: <span class="Identifier">break</span><span class="Delimiter">;</span>
<span class="Normal">case</span> BREAK_IF: <span class="Identifier">break</span><span class="Delimiter">;</span>
<span class="Normal">case</span> BREAK_UNLESS: <span class="Identifier">break</span><span class="Delimiter">;</span>
<span class="Normal">case</span> LOOP: <span class="Identifier">break</span><span class="Delimiter">;</span>
<span class="Normal">case</span> LOOP_IF: <span class="Identifier">break</span><span class="Delimiter">;</span>
<span class="Normal">case</span> LOOP_UNLESS: <span class="Identifier">break</span><span class="Delimiter">;</span>
</pre>
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