"Repeat variants for: until loop; loop counting down over a numeric or enumerated value range; loop n times. For any loop, optionally assign a loop counter variable; for looping through tables optionally assign a row number variable. Allows more flexible syntax for the existing repeat loops. For 6M62."
This is experimental and mostly made out of the undocumented features in the Standard Rules the docs call on us not to use. Adds while and until loops. Among other things, this makes it easy to loop indefinitely until a condition is met, which comes in handy sometimes. On the other hand, this makes it easy to loop indefinitely. Inform 7's existing repeat statements make it hard to infinitely loop, which I'm guessing was a deliberate design decision. So be warned that these loops are powerful tools whose power is by default pointed at your foot: make sure your loop incrementally approaches its exit condition. If you Include If True by Zed Lopez, then while and until will be able to take plain truth states instead of full conditionals. Infinitely loop (your obligation to break out): ``` repeat while true: ``` Repeat down across a range: ``` repeat with x running from 12 down to 2: ``` ``` repeat with hue running from indigo down to orange: ``` For all of the loops, you can also provide a loop index variable. Don't alter the loop index variable manually or it'll cease being a useful loop index variable. Enumerated values in a specified range: ``` repeat with the-color running from red to blue with index i: ``` Descriptions of objects: ``` repeat with closed-thing running through closed things with index i: ``` Lists: ``` repeat with item running through L with index i: ``` To save you the trouble of reversing a list you want to iterate through, you can specify backwards. ``` repeat for item in L backwards: ``` or ``` repeat for item in L in reverse: ``` Tables with row number: ``` repeat through Table of Regrets with row number row-id; ``` But when you're going through a table backwards or sorting by a column, the row number will typically be different from a count of iterations through the loop, so if you really want the latter, too: ``` repeat through Table of Regrets with row number row-id and index i; ``` (There isn't a provided option for just the index without the row number.) The compiler does magic I can't reproduce to let the same phrase preamble work for descriptions of objects and descriptions of enumerated values. So the loop over a description of values with index case only works for objects. If you're working with enumerated values and you want the index, do your choice of the following: ``` [ if and only if you're working across the whole range: ] repeat with the-color running through colors: let index be the-color cast as a number; [...] ``` or: ``` [ alternative for whole range: ] repeat for the-color from the first value in colors to the last value in colors with index: ``` or: ``` [ other than whole range: ] repeat for the-color from red to yellow with index i begin; [or:] Definition: a color (called C) is infragreen if C < green. let i be 0; repeat for c in infragreen colors begin; [works because unfair ni magic ] increment i; ``` Reserve this form for descriptions of objects: ``` repeat with drafty running through open containers with index i: ``` Be warned that if you do try using it with enumerated values, there *won't* be an error: the body of the loop won't be executed; it will just return immediately. Also modifies existing syntax: "repeat running through" and "repeat through" are interchangeable (i.e., "running" is permissible while looping through tables, and omitting it is permissible everywhere) "for" may replace "with" "in" may replace "from" "in" may replace "through" So all of the following are equivalent: Repeat with i running from 1 to 10 Repeat with i from 1 to 10 Repeat for i in 1 to 10 And these are equivalent: Repeat running through the Table of Regrets: Repeat through the Table of Regrets: Repeat in the Table of Regrets: other examples: repeat through the table of regrets backwards by decision-badness using row number row-id Section Changelog 1/211027 Added repeat n times loop. Improved documentation. Added looping through lists backwards. 1/210930 Add separate case for repeat through list of text with index case, which had been failing. Any list of a block-valued kind other than text will still fail. 1/210928 Use I6-native do-until loop; prior implementation could break with multiple until loops
Version 1/211127 of Strange Loopiness by Zed Lopez begins here. "Repeat variants for: until loop; loop counting down over a numeric or enumerated value range; loop n times. For any loop, optionally assign a loop counter variable; for looping through tables optionally assign a row number variable. Allows more flexible syntax for the existing repeat loops. For 6M62." Part while loop Section while conditional with index To while (c - a condition) with/using index (index - nonexisting number variable) begin -- end loop: (- {index} = 0; while ({c} && ++{index}) -). Part repeat until Chapter until condition Section until condition plain [ with an until loop, body is always executed at least once: the condition is tested at the end of the loop, not the beginning. ] To repeat until (c - a condition) begin -- end loop: (- do {-block} until ({c}); -) Section until condition with index To repeat until (c - a condition) with/using index (index - nonexisting number variable) begin -- end loop: (- {index} = 0; do if (++{index}) {-block} until ({c}); -) Book Descending Part descent plain To repeat with/for the/a/an/-- (loopvar - nonexisting K variable) running/-- from/in (v - value of kind K) down to (w - K) begin -- end loop: (- for ({loopvar}={v}: {loopvar}>={w}: {loopvar}--) -). Part descent with index To repeat with/for the/a/an/-- (loopvar - nonexisting K variable) running/-- from/in (v - value of kind K) down to (w - K) with/using index (index - a nonexisting number variable) begin -- end loop: (- for ({loopvar}={v}, {index} = 1: {loopvar}>={w}: {loopvar}--, {index}++ ) -). Book Overwriting Standard Rules Section Clobber Standard Repeat Rules (in place of Section SR5/3/3 - Control phrases - Repeat in Standard Rules by Graham Nelson) Use ineffectual. Part Alternate Repetitions Chapter Specified range To repeat with/for the/a/an/-- (loopvar - nonexisting K variable) running/-- from/in (v - value of kind K) to (w - K) begin -- end loop (documented at ph_repeat): (- for ({loopvar}={v}: {loopvar}<={w}: {loopvar}++ ) -). Section Specified range with index To repeat with/for the/a/an/-- (loopvar - nonexisting K variable) running/-- from/in (v - value of kind K) to (w - K) with/using index (index - a nonexisting number variable) begin -- end loop (documented at ph_repeat): (- for ({loopvar}={v}, {index} = 1: {loopvar}<={w}: {loopvar}++, {index}++ ) -). Chapter Description of objects [ this works with objects *or* values because -primitive-definition gets up to some magic ] To repeat with/for the/a/an/-- (loopvar - nonexisting K variable) running/-- through/in (OS - description of values of kind K) begin -- end loop (documented at ph_runthrough): (- {-primitive-definition:repeat-through} -). Section Description of objects with index [ This only works with objects 'cause I can't reproduce the magic. See the documentation below for workarounds. ] To repeat with/for the/a/an/-- (loopvar - nonexisting K variable) running/-- through/in (OS - description of values of kind K) with index (index - nonexisting number variable) begin -- end loop (documented at ph_runthrough): (- {index} = 0; objectloop({loopvar} ofclass Object) if ({-matches-description:loopvar:OS} && ++{index}) -). Chapter List of values To repeat with/for the/a/an/-- (loopvar - nonexisting K variable) running/-- through/in (L - list of values of kind K) begin -- end loop (documented at ph_repeatlist): (- {-primitive-definition:repeat-through-list} -). Section list of values with index To repeat with/for the/a/an/-- (loopvar - nonexisting K variable) running/-- through/in (L - list of values of kind K) with/using index (index - nonexisting number variable) begin -- end loop (documented at ph_repeatlist): (- {-my:1} = LIST_OF_TY_GetLength({L}); for ({index} = 1 : {index} <= {-my:1} : {index}++ ) if ({loopvar} = LIST_OF_TY_GetItem({L}, {index})) -). Section list of texts with index To repeat with/for the/a/an/-- (loopvar - nonexisting text variable) running/-- through/in (L - list of texts) with/using index (index - nonexisting number variable) begin -- end loop: (- {-my:1} = LIST_OF_TY_GetLength({L}); ! texts for ({index} = 1 : {index} <= {-my:1} : {index}++ ) if (BlkValueCopy({-by-reference:loopvar}, LIST_OF_TY_GetItem({L}, {index}))) -). Chapter List of values backwards Section list of values backwards To repeat with/for the/a/an/-- (loopvar - nonexisting K variable) running/-- through/in (L - list of values of kind K) in/-- reverse/backwards order/-- begin -- end loop: (- {-my:1} = LIST_OF_TY_GetLength({L}); for ({-my:2} = {-my:1} : {-my:2} >= 1 : {-my:2}--) if ({loopvar} = LIST_OF_TY_GetItem({L}, {-my:2})) -). Section list of texts backwards To repeat with/for the/a/an/-- (loopvar - nonexisting text variable) running/-- through/in (L - list of texts) in/-- reverse/backwards order/-- begin -- end loop: (- {-my:1} = LIST_OF_TY_GetLength({L}); ! texts backward for ({-my:2} = {-my:1} : {-my:2} >= 1 : {-my:2}--) if (BlkValueCopy({-by-reference:loopvar}, LIST_OF_TY_GetItem({L}, {-my:2}))) -). [ note: when looping backwards, index isn't entry number; it's a loop counter like usual ] Section list of values with index backwards To repeat with/for the/a/an/-- (loopvar - nonexisting K variable) running/-- through/in (L - list of values of kind K) in/-- reverse/backwards order/-- with/using index (index - nonexisting number variable) begin -- end loop: (- {-my:1} = LIST_OF_TY_GetLength({L}); for ({-my:2} = {-my:1},{index} = 1 : {-my:2} >= 1 : {-my:2}--, {index}++ ) if ({loopvar} = LIST_OF_TY_GetItem({L}, {-my:2})) -). Section list of texts with index backwards To repeat with/for the/a/an/-- (loopvar - nonexisting text variable) running/-- through/in (L - list of texts) in/-- reverse/backwards order/-- with/using index (index - nonexisting number variable) begin -- end loop: (- {-my:1} = LIST_OF_TY_GetLength({L}); ! texts for ({-my:2} = {-my:1},{index}=1 : {-my:2} >= 1 : {-my:2}--,{index}++ ) if (BlkValueCopy({-by-reference:loopvar}, LIST_OF_TY_GetItem({L}, {-my:2}))) -). Chapter Table Section forward To repeat running/-- through/in (T - table name) begin -- end loop (documented at ph_repeattable): (- @push {-my:ct_0}; @push {-my:ct_1}; for ({-my:1}={T}, {-my:2}=1, ct_0={-my:1}, ct_1={-my:2}: {-my:2}<=TableRows({-my:1}): {-my:2}++, ct_0={-my:1}, ct_1={-my:2}) if (TableRowIsBlank(ct_0, ct_1)==false) {-block} @pull {-my:ct_1}; @pull {-my:ct_0}; -). Section forward with row number To repeat running/-- through/in (T - table name) with row number (row_number - nonexisting number variable) begin -- end loop (documented at ph_repeattable): (- @push {-my:ct_0}; @push {-my:ct_1}; for ({-my:1}={T}, {-my:2}=1, ct_0={-my:1}, ct_1={-my:2}, {row_number} = ct_1: {-my:2}<=TableRows({-my:1}): {-my:2}++, ct_0={-my:1}, ct_1={-my:2}, {row_number} = ct_1) if (TableRowIsBlank(ct_0, ct_1)==false) {-block} @pull {-my:ct_1}; @pull {-my:ct_0}; -). Section forward with row number and index To repeat running/-- through/in (T - table name) with row number (row_number - nonexisting number variable) and index (index - nonexisting number variable) begin -- end loop (documented at ph_repeattable): (- @push {-my:ct_0}; @push {-my:ct_1}; for ({-my:1}={T}, {-my:2}=1, ct_0={-my:1}, ct_1={-my:2}, {row_number} = ct_1, {index} = 1: {-my:2}<=TableRows({-my:1}): {-my:2}++, ct_0={-my:1}, ct_1={-my:2}, {row_number} = ct_1, {index}++) if (TableRowIsBlank(ct_0, ct_1)==false) {-block} @pull {-my:ct_1}; @pull {-my:ct_0}; -). Section reverse To repeat running/-- through/in (T - table name) in/-- reverse/backwards order/-- begin -- end loop (documented at ph_repeattablereverse): (- @push {-my:ct_0}; @push {-my:ct_1}; for ({-my:1}={T}, {-my:2}=TableRows({-my:1}), ct_0={-my:1}, ct_1={-my:2}: {-my:2}>=1: {-my:2}--, ct_0={-my:1}, ct_1={-my:2}) if (TableRowIsBlank(ct_0, ct_1)==false) {-block} @pull {-my:ct_1}; @pull {-my:ct_0}; -). Section reverse with row number To repeat running/-- through/in (T - table name) in/-- reverse/backwards order/-- with row number (row_number - nonexisting number variable) begin -- end loop (documented at ph_repeattablereverse): (- @push {-my:ct_0}; @push {-my:ct_1}; for ({-my:1}={T}, {-my:2}=TableRows({-my:1}), ct_0={-my:1}, ct_1={-my:2}, {row_number}=ct_1: {-my:2}>=1: {-my:2}--, ct_0={-my:1}, ct_1={-my:2}, {row_number}=ct_1) if (TableRowIsBlank(ct_0, ct_1)==false) {-block} @pull {-my:ct_1}; @pull {-my:ct_0}; -). Section reverse with row number and index To repeat running/-- through/in (T - table name) in/-- reverse/backwards order/-- with row number (row_number - nonexisting number variable) and index (index - nonexisting number variable) begin -- end loop (documented at ph_repeattablereverse): (- @push {-my:ct_0}; @push {-my:ct_1}; for ({-my:1}={T}, {-my:2}=TableRows({-my:1}), ct_0={-my:1}, ct_1={-my:2}, {row_number}=ct_1, {index} = 1: {-my:2}>=1: {-my:2}--, ct_0={-my:1}, ct_1={-my:2}, {row_number}=ct_1, {index}++) if (TableRowIsBlank(ct_0, ct_1)==false) {-block} @pull {-my:ct_1}; @pull {-my:ct_0}; -). Section forward sorted by column To repeat running/-- through/in (T - table name) sorted/-- in/by (TC - table column) order/-- begin -- end loop (documented at ph_repeattablecol): (- @push {-my:ct_0}; @push {-my:ct_1}; for ({-my:1}={T}, {-my:2}=TableNextRow({-my:1}, {TC}, 0, 1), ct_0={-my:1}, ct_1={-my:2}: {-my:2}~=0: {-my:2}=TableNextRow({-my:1}, {TC}, {-my:2}, 1), ct_0={-my:1}, ct_1={-my:2}) {-block} @pull {-my:ct_1}; @pull {-my:ct_0}; -). Section forward sorted by column with row number To repeat running/-- through/in (T - table name) sorted/-- in/by (TC - table column) order/-- with row number (row_number - nonexisting number variable) begin -- end loop (documented at ph_repeattablecol): (- @push {-my:ct_0}; @push {-my:ct_1}; for ({-my:1}={T}, {-my:2}=TableNextRow({-my:1}, {TC}, 0, 1), ct_0={-my:1}, ct_1={-my:2}, {row_number}=ct_1: {-my:2}~=0: {-my:2}=TableNextRow({-my:1}, {TC}, {-my:2}, 1), ct_0={-my:1}, ct_1={-my:2},{row_number}=ct_1) {-block} @pull {-my:ct_1}; @pull {-my:ct_0}; -). Section forward sorted by column with row number and index To repeat running/-- through/in (T - table name) sorted/-- in/by (TC - table column) order/-- with row number (row_number - nonexisting number variable) and index (index - nonexisting number variable) begin -- end loop (documented at ph_repeattablecol): (- @push {-my:ct_0}; @push {-my:ct_1}; for ({-my:1}={T}, {-my:2}=TableNextRow({-my:1}, {TC}, 0, 1), ct_0={-my:1}, ct_1={-my:2}, {row_number}=ct_1, {index} = 1: {-my:2}~=0: {-my:2}=TableNextRow({-my:1}, {TC}, {-my:2}, 1), ct_0={-my:1}, ct_1={-my:2},{row_number}=ct_1, {index}++) {-block} @pull {-my:ct_1}; @pull {-my:ct_0}; -). Section reverse sorted by column To repeat running/-- through/in (T - table name) sorted/-- in/by reverse/backwards (TC - table column) order/-- begin -- end loop (documented at ph_repeattablecolreverse): (- @push {-my:ct_0}; @push {-my:ct_1}; for ({-my:1}={T}, {-my:2}=TableNextRow({-my:1}, {TC}, 0, -1), ct_0={-my:1}, ct_1={-my:2}: {-my:2}~=0: {-my:2}=TableNextRow({-my:1}, {TC}, {-my:2}, -1), ct_0={-my:1}, ct_1={-my:2}) {-block} @pull {-my:ct_1}; @pull {-my:ct_0}; -). Section reverse sorted by column with row number To repeat running/-- through/in (T - table name) sorted/-- in/by reverse/backwards (TC - table column) order/-- with row number (row_number - nonexisting number variable) begin -- end loop (documented at ph_repeattablecolreverse): (- @push {-my:ct_0}; @push {-my:ct_1}; for ({-my:1}={T}, {-my:2}=TableNextRow({-my:1}, {TC}, 0, -1), ct_0={-my:1}, ct_1={-my:2}, {row_number}=ct_1: {-my:2}~=0: {-my:2}=TableNextRow({-my:1}, {TC}, {-my:2}, -1), ct_0={-my:1}, ct_1={-my:2}, {row_number}=ct_1) {-block} @pull {-my:ct_1}; @pull {-my:ct_0}; -). Section reverse sorted by column with row number and index To repeat running/-- through/in (T - table name) sorted/-- in/by reverse/backwards (TC - table column) order/-- with row number (row_number - nonexisting number variable) and index (index - nonexisting number variable) begin -- end loop (documented at ph_repeattablecolreverse): (- @push {-my:ct_0}; @push {-my:ct_1}; for ({-my:1}={T}, {-my:2}=TableNextRow({-my:1}, {TC}, 0, -1), ct_0={-my:1}, ct_1={-my:2}, {row_number}=ct_1, {index} = 1: {-my:2}~=0: {-my:2}=TableNextRow({-my:1}, {TC}, {-my:2}, -1), ct_0={-my:1}, ct_1={-my:2}, {row_number}=ct_1, {index}++) {-block} @pull {-my:ct_1}; @pull {-my:ct_0}; -). Part times Chapter times without index To repeat for/-- (N - a number) time/times begin -- end loop: (- for ({-my:1}=1: {-my:1}<={N}: {-my:1}++ ) -). Chapter times with index [ there isn't a good reason to use this instead of ``repeat for i in 1 to 5`` but for consistency... ] To repeat for/-- (N - a number) time/times with/using index (index - nonexisting number variable) begin -- end loop: (- for ({index}=1: {index}<={N}: {index}++ ) -). Book Casting (For use without Central Typecasting by Zed Lopez) To decide which K is the/a/an/-- (unknown - a value) cast as the/a/an/-- (name of kind of value K): (- {unknown} -). Strange Loopiness ends here.
Include Strange Loopiness by Zed Lopez.