diff --git a/NEWS b/NEWS index ca83cdd..ecf2df7 100644 --- a/NEWS +++ b/NEWS @@ -6,6 +6,13 @@ The changes compared to 2.3.0 are: o Added examples updating the life simulation to illustrate the color and computed style features. o You can compute the styles for cells, with an additional expression per cell. +o Computation of current values for cells without clocked expressions now + always depends on contemporaneous current values rather than prior values, + even when the sheet is clocked. This means, for example, an entry whose base + value is the sum of a column and which has no will always resolve to the + current sum of that column, even if the column contains clocked values. + (This is a breaking change in that prior to this modification, such a cell + when clocked would contain the sum of the prior values in that column.) o New token types: style and bool. o Comparison operators return bool rather than int (Note this can be a breaking change; you may need to wrap comparisons in int() if you are using the result @@ -21,8 +28,13 @@ o Addition of hexact float format, which allows for exact round trips to ASCII o New token type: funcall (which basically amounts to an expression). This allows parsed rather than unparsed expressions to be stored in cells, and allows macros which receive their arguments unevaluated. -o sum(), min(), and max() can now operate over their list of arguments as well - as over a block. +o New region/accumulator operation count() that counts truthy cells (rather + that just nonempty cells as n() does) added. +o All region/accumulator operations including sum(), min(), and max() can + now operate over their list of arguments as well as over a block. +o All region/accumulator operations can take an optional expression when + operating over a block that generates the values to be accumulated (rather + than just taking the values directly from the block). o Added floor(), ceil(), trunc(), and round() functions for finding integers associated with doubles, eliminating (note possible breaking change) the int conversion with two rounding directions. diff --git a/doc/teapot.lyx b/doc/teapot.lyx index 176babb..fab9eb1 100644 --- a/doc/teapot.lyx +++ b/doc/teapot.lyx @@ -346,7 +346,7 @@ name "fig:Three-Dimensional-Spread-Sheet" \end_inset -Three-Dimensional Spread Sheet Layout +Three-Dimensional Spreadsheet Layout \end_layout \end_inset @@ -794,7 +794,7 @@ The sheet is currently in reset condition and the result is 1. \begin_layout Standard After this introductory chapter, you should be familiar with the basic concepts - in spread sheets. + in spreadsheets. The next chapters explain all operations available in detail. You should read them to get an overview of the possibilities offered by @@ -4595,7 +4595,7 @@ CSV (.csv) \begin_layout Standard CSV (comma separated value) files only contain the data, not the expressions calculating it. - Many spread sheets can generate this file format and many graphics programs + Many spreadsheets can generate this file format and many graphics programs like gnuplot(1) can read it. The field separator usually is a tab or comma, strings may be enclosed in double quotes and decimal numbers have a dot to mark the fractional @@ -5315,34 +5315,170 @@ goto 5.12.4 \emph default . - \end_layout \begin_layout Section -Expressions +Sheets, Cells, and Clocking \end_layout \begin_layout Standard -Cells consist of a base (reset) expression, a clocked expression, a style - expression, and a current value. - If the sheet is currently in the reset state (the default), all cells display - their base value as current value. +A +\emph on +sheet +\emph default + is a three-dimensional collection of +\emph on +cells +\emph default +. + The slices in the X, Y, and Z directions are called the +\emph on +columns +\emph default +, +\emph on +rows +\emph default +, and +\emph on +layers +\emph default +, respectively. + At any given time, the valid coordinates for a sheet are all non-negative + integers up to some current limit in each of the X, Y, and Z directions, + which may be different in each direction. + Generally speaking, direct references to cells with negative coordinates + are an error, whereas indirect references to cells with negative coordinates + and all references to cells with coordinates beyond the current limits + act as references to empty cells with all default attributes/styles. \end_layout \begin_layout Standard -When the sheet is clocked (see Table +Each cell has three expressions, all of which are optional: a base (reset) + expression, a clocked expression, and a style expression. + It also has an associated current value. + See section +\begin_inset CommandInset ref +LatexCommand ref +reference "sec:Expressions" +plural "false" +caps "false" +noprefix "false" + +\end_inset + + for the semantics of expressions and values. + When the sheet is in the reset state (the default/initial state), all cells + set their current values to the value of their base expression; references + to other cells use those other cells' current values. + The recomputation of current values updates referred-to cells first in + an effort to produce the expected, correct values. + However, if there are circular references among cells, this update process + does not attempt to produce a fully self-consistent state, in that a given + cell is only updated once. + Hence the resulting current values can depend on the order updates occur, + and it may happen that a cell's current value is not equal to the value + of its base expression computed with current values of all cells. + This behavior may seem problematic, but in fact it's not always possible + to produce a self-consistent state. + The simplest example is if the base expression for the cell with coordinates + (0,0,0) is @(0,0,0)+1, since no number is one more than itself. + Moreover, in the absence of circular reference chains among the base expression +s, the recomputation of current values is guaranteed to reach a consistent + state for all cells. + The bottom line is that although circular references in base expressions + are not disallowed, their utility may be limited because their behavior + is relatively unpredictable. +\end_layout + +\begin_layout Standard +When a sheet is clocked (see Table \begin_inset CommandInset ref LatexCommand ref reference "tab:Key-Bindings-in" \end_inset -), the clocked expression is evaluated, using the current value of referenced - cells. - The new current value is the result of that evaluation. +), every cell with a clocked expression is clocked. + When a cell is clocked (either because the sheet was clocked or by virtue + of the clock() function documented in section +\begin_inset CommandInset ref +LatexCommand ref +reference "subsec:All-other-functions" +plural "false" +caps "false" +noprefix "false" + +\end_inset + +), its clocked expression is evaluated using the current value of all cells + referenced directly or indirectly, including cells that are also currently + being clocked. + Then the new current value of (all of the) clocked cell(s) is set to the + result of that evaluation. + Finally, the current values of the unclocked cells (which include any cells + that have no clocked expression) are recomputed based on the new current + values. + The upshot of these rules is that one can control the updating of potentially + circular references precisely: the computation of clocked expressions always + uses values of all cells, including other clocked cells, from the previous + +\begin_inset Quotes eld +\end_inset + +tick +\begin_inset Quotes erd +\end_inset + +, and the computation of base expressions uses values of all cells, including + other unclocked cells, from the current tick. +\end_layout + +\begin_layout Standard +Finally, whenever the style of a given cell is needed, for example to display + the cell, its style expression is evaluated based on the current values + of all cells to which it refers directly or indirectly. + The expression must evaluate to a style value (see subsection +\begin_inset CommandInset ref +LatexCommand ref +reference "subsec:Data-Types" +plural "false" +caps "false" +noprefix "false" + +\end_inset + +) and that value provides the style of the cell. +\end_layout + +\begin_layout Section +\begin_inset CommandInset label +LatexCommand label +name "sec:Expressions" + +\end_inset + +Expressions and values +\end_layout + +\begin_layout Standard +In +\noun on +teapot +\noun default +, values are specific data items and expressions are the formulas that can + be evaluated to produce those values. + This section describes the possible values, the allowed syntax of expressions, + and the semantics of valid expressions. \end_layout \begin_layout Subsection +\begin_inset CommandInset label +LatexCommand label +name "subsec:Data-Types" + +\end_inset + Data Types \end_layout @@ -6996,6 +7132,12 @@ sum Returns the sum of the accumulated values (recall for strings this is \end_layout \begin_layout Subsubsection +\begin_inset CommandInset label +LatexCommand label +name "subsec:All-other-functions" + +\end_inset + All other functions \end_layout @@ -10123,7 +10265,7 @@ How do I hide intermediate results? \end_layout \begin_layout Standard -If you used flat, two-dimensional spread sheets before, you are probably +If you used flat, two-dimensional spreadsheets before, you are probably used to hidden cells which contain intermediate results, global constants, scratch areas and the like. diff --git a/src/common/cell.c b/src/common/cell.c index efc983e..2c921af 100644 --- a/src/common/cell.c +++ b/src/common/cell.c @@ -50,6 +50,11 @@ Token gettok(const Cell *cell, TokVariety v) return cell->tok[v]; } +/* iterable -- does cell have iteration content? */ +bool iterable(const Cell* cell) { + return (cell != NULLCELL) && cell->tok[ITER_CONT].type != EMPTY; +} + /* locked -- is cell locked? */ bool locked(const Cell *cell) { diff --git a/src/common/cell.h b/src/common/cell.h index 40c955b..72f5e82 100644 --- a/src/common/cell.h +++ b/src/common/cell.h @@ -32,6 +32,7 @@ typedef struct typedef enum {ALTER_LABEL, PRESERVE_LABEL} LabelHandling; Token gettok(const Cell *cell, TokVariety v); +bool iterable(const Cell *cell); bool locked(const Cell *cell); bool ignored(const Cell *cell); const char *getlabel(const Cell *cell); diff --git a/src/common/sheet.c b/src/common/sheet.c index 5b26b02..c728863 100644 --- a/src/common/sheet.c +++ b/src/common/sheet.c @@ -692,14 +692,33 @@ void update(Sheet *sheet) upd_clock = true; recompvalue(sheet, w); } + bool current_changed = false; for (ALL_CELLS_IN_SHEET(sheet,i,cell)) { if (cell && cell->clock_resolving) { tfree(&(cell->tok[CURR_VAL])); cell->tok[CURR_VAL] = cell->tok[RES_VAL];; - cell->tok[RES_VAL].type = EMPTY; - cell->clock_resolving = false; + cell->tok[RES_VAL].type = EMPTY; + current_changed = true; + } + } + if (current_changed) { + /* Recompute all of the non-clocked cells so that they get the values + of the newly-changed clocked cells + */ + for (ALL_CELLS_IN_SHEET(sheet, i, cell)) { + if (cell) { + if (cell->clock_resolving) { + cell->clock_resolving = false; + } else { + cell->updated = false; + } + } + } + for (ALL_LOCS_IN_SHEET(sheet, w)) { + upd_clock = true; + recompvalue(sheet, w); } } upd_clock = false; @@ -905,10 +924,11 @@ void clk(Sheet *sheet, const Location at) { assert(sheet != (Sheet*)0); assert(IN_OCTANT(at)); - assert(LOC_WITHIN(sheet,at)); - if (CELL_AT(sheet,at)) + assert(LOC_WITHIN(sheet, at)); + Cell* toclock = CELL_AT(sheet, at); + if (iterable(toclock)) { - CELL_AT(sheet,at)->clock_requested = true; + toclock->clock_requested = true; sheet->clk = true; } }