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start making it postfix
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prefix by default is too confusing. better to provide syntax for things
that work better as prefix (eg if, while), and leave everything else
left-to-right. idk i've felt committed to the prefix thing for a while
but I can just feel the language fighting against it. now I get why
everything is postfix. HOWEVER the whole "condition [then] [else] if"
thing is awful, so I'm providing syntax to avoid stuff like that.
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@cassowarii
cassowarii committed Jun 9, 2018
1 parent 5a80d3e commit 20d64e8
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Showing 3 changed files with 79 additions and 51 deletions.
3 changes: 1 addition & 2 deletions lexer.l
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Original file line number Diff line number Diff line change
Expand Up @@ -139,8 +139,7 @@ IDONECH [^{}[\]()\"\' \t\n,;]|{UONLY}
: |
; |
, |
# |
\| return yytext[0];
# return yytext[0];

\r|\n {
return '\n';
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16 changes: 8 additions & 8 deletions lib_control.c
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Original file line number Diff line number Diff line change
Expand Up @@ -4,9 +4,9 @@
* below B and C, take the top element, and run
* B if truthy, C if falsy. (integerwise.) */
void lib_if(AStack *stack, AVarBuffer *buffer) {
AValue *ifpart = stack_get(stack, 0);
AValue *ifpart = stack_get(stack, 2);
AValue *thenpart = stack_get(stack, 1);
AValue *elsepart = stack_get(stack, 2);
AValue *elsepart = stack_get(stack, 0);
stack_pop(stack, 3);

eval_block(stack, buffer, ifpart);
Expand All @@ -31,9 +31,9 @@ void lib_if(AStack *stack, AVarBuffer *buffer) {
* B if truthy, C if falsy. But put the top element
* of the stack back before running B or C. */
void lib_ifstar(AStack *stack, AVarBuffer *buffer) {
AValue *ifpart = stack_get(stack, 0);
AValue *ifpart = stack_get(stack, 2);
AValue *thenpart = stack_get(stack, 1);
AValue *elsepart = stack_get(stack, 2);
AValue *elsepart = stack_get(stack, 0);
AValue *top = stack_get(stack, 3);

/* don't pop off 'top' */
Expand Down Expand Up @@ -62,8 +62,8 @@ void lib_ifstar(AStack *stack, AVarBuffer *buffer) {
* the stack below B and apply B over and over
* again until applying A gives a falsy value. */
void lib_while (AStack *stack, AVarBuffer *buffer) {
AValue *condpart = stack_get(stack, 0);
AValue *looppart = stack_get(stack, 1);
AValue *condpart = stack_get(stack, 1);
AValue *looppart = stack_get(stack, 0);
stack_pop(stack, 2);

eval_block(stack, buffer, condpart);
Expand Down Expand Up @@ -94,8 +94,8 @@ void lib_while (AStack *stack, AVarBuffer *buffer) {
* But keep the top value on the stack after
* applying A each time. */
void lib_whilestar(AStack *stack, AVarBuffer *buffer) {
AValue *condpart = stack_get(stack, 0);
AValue *looppart = stack_get(stack, 1);
AValue *condpart = stack_get(stack, 1);
AValue *looppart = stack_get(stack, 0);
AValue *top = stack_get(stack, 2);

stack_pop(stack, 2);
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111 changes: 70 additions & 41 deletions parse.c
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Original file line number Diff line number Diff line change
Expand Up @@ -415,9 +415,9 @@ ANameSeqNode *parse_nameseq_opt(AParseState *state) {
return result;
}

/* Parse either a '|' or a newline. Doesn't matter which. */
/* Parse either a ';' or a newline. Doesn't matter which. */
int parse_separator(AParseState *state) {
if (ACCEPT('|')) {
if (ACCEPT(';')) {
return 1;
} else if (ACCEPT('\n')) {
return 1;
Expand Down Expand Up @@ -661,50 +661,79 @@ AAstNode *parse_word(AParseState *state) {
* - a binding:
* - an arrow, a list of names, a cmplx_word.
* Thus we can write something like:
* 5 6 -> a b (+ a b)
* 5 6 -> a b (a b +)
* and this counts as a 'full' wordline. */
AWordSeqNode *parse_wordline(AParseState *state) {
AWordSeqNode *result = ast_wordseq_new();

/* If there's no words before the binding arrow,
* we'll never enter this loop in the first place
* -- perfect! */
AAstNode *word = parse_word(state);
while (1) {
/* Represents everything between the last colon we've
* seen and the next colon (or end line or whatever.) */
AWordSeqNode *section = ast_wordseq_new();

while (word != &nonword) {
if (word == NULL) {
free_wordseq_node(result);
return NULL;
}
/* If there's no words before the binding arrow,
* we'll never enter this loop in the first place
* -- perfect! */
AAstNode *word = parse_word(state);

if (word->type == paren_node) {
/* Unwrap the paren node, and put the stuff
* we've done before AFTER it. */
AWordSeqNode *newresult = word->data.inside;
ast_wordseq_concat(newresult, result);
/* Essentially the inside of the paren-node
* becomes the new main sequence. */
free(result);
free(word);
result = newresult;
} else {
ast_wordseq_prepend(result, word);
}
while (word != &nonword) {
if (word == NULL) {
free_wordseq_node(result);
free_wordseq_node(section);
return NULL;
}

word = parse_word(state);
}
if (word->type == paren_node) {
/* Unwrap the paren node, and put the stuff
* we've done before AFTER it. */
AWordSeqNode *newresult = word->data.inside;
ast_wordseq_concat(section, newresult);
/* Essentially the inside of the paren-node
* becomes the new main sequence. */
free(section);
free(word);
section = newresult;
} else {
ast_wordseq_append(section, word);
}

/* If we found a bind arrow, then the optional
* second part must be here. */
if (ACCEPT(T_BIND)) {
unsigned int bindline = LINENUM;
ANameSeqNode *names = parse_nameseq_opt(state);
word = parse_word(state);
}

AAstNode *node = parse_cmplx_word(state);
if (node != NULL) {
AWordSeqNode *innerbind = unwrap_node(node);
AAstNode *bind = ast_bindnode(bindline, names, innerbind);
ast_wordseq_append(result, bind);
/* If we found a bind arrow, then the optional
* second part must be here. */
if (ACCEPT(T_BIND)) {
unsigned int bindline = LINENUM;
ANameSeqNode *names = parse_nameseq_opt(state);

AAstNode *node = parse_cmplx_word(state);
if (node != NULL) {
AWordSeqNode *innerbind = unwrap_node(node);
AAstNode *bind = ast_bindnode(bindline, names, innerbind);
ast_wordseq_append(result, bind);
}
/* Now that must be the end of the line... I guess? */
/* TODO we don't need a special case here anymore actually.
* Please move the bind-arrow-parsing code into parse_cmplx_word
* instead, and add the bind-arrow to complex_word_leadin.
* Then we can just chain them together now since we go left-to-right */
break;
} else if (ACCEPT(':')) {
/* Everything we've done so far is to be done AFTER the stuff we find next.
* So we put these at the beginning of the overall sequence. */
/* TODO this is inefficient, fix up later */
ast_wordseq_concat(section, result);
free(result);
result = section;
section = ast_wordseq_new();
} else {
/* We probably hit a new line. Stick what we've got at the beginning and
* call it a day. */
ast_wordseq_concat(section, result);
free(result);
result = section;
section = ast_wordseq_new();
break;
}
}

Expand All @@ -715,7 +744,7 @@ AWordSeqNode *parse_wordline(AParseState *state) {
* This is what makes up the elements of lists,
* the inside of blocks, etc.
* A series of 'word-lines' separated by newlines
* or pipe characters ('|'). */
* or semicolons. */
AWordSeqNode *parse_words(AParseState *state) {
AWordSeqNode *result = ast_wordseq_new();

Expand Down Expand Up @@ -748,7 +777,7 @@ AWordSeqNode *parse_interactive_words(AParseState *state) {
}
ast_wordseq_concat(result, line);
free(line);
} while (ACCEPT('|'));
} while (ACCEPT(';'));

if (!EXPECT('\n')) {
PANIC('\n');
Expand Down Expand Up @@ -1013,8 +1042,8 @@ void interact(ASymbolTable *symtab) {
NULL, /* current interactive string */
0, /* chars left to read from string */
0, /* current index into string */
"> ", /* Prompt #1 */
"? ", /* Prompt #2 */
"alma> ", /* Prompt #1 */
"... > ", /* Prompt #2 */
0, /* Nested let..in */
0, /* Nested function decls */
0, /* Nested comments */
Expand Down

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