Methods for composing formulas in an electronic spreadsheet system

Claims

What is claimed is:

1. In an electronic spreadsheet system for modeling user-specified information in a data model comprising a plurality of formulas entered by a user, each of said formulas evaluating to a result, a method for assisting the user with correctly entering formulas, the method comprising:

(a) storing syntax rules specifying valid syntax for formulas;

(b) receiving user input for entering a formula;

(c) parsing said user input, based on said syntax rules, into at least one formula node, said at least one node storing a subexpression of the formula;

(d) creating, based on said at least one formula node, an outline view of the formula; and

(e) displaying said outline view to the user.

2. The method of claim 1, wherein step (e) comprises:

for each of said at least one formula node, displaying its subexpression as a node on a hierarchical outline.

3. The method of claim 1, further comprising:

receiving a user request for selecting one of said nodes; and

displaying in an edit field the subexpression stored by the selected node.

4. The method of claim 3, further comprising:

receiving user input at the edit field for modifying the subexpression; and

updating the outline view of the formula based on the modified subexpression.

5. The method of claim 3, further comprising:

computing a result for the subexpression; and

displaying said computed result to the user.

6. The method of claim 5, further comprising:

if a result cannot be correctly computed, displaying an error value as the result for the subexpression.

7. The method of claim 6, wherein said error value is a spreadsheet "ERR" value.

8. The method of claim 1, wherein step (c) includes:

tokenizing said user input into a sequence of opcodes; and

scanning said sequence of opcodes for building a tree of formula nodes.

9. The method of claim 1, wherein step (c) includes:

displaying as a node of the outline view each subexpression of said at least one formula node; and

displaying a folder icon next to some of the nodes of the ouline for indicating to the user that the nodes can be expanded and collapsed.

10. A data processing system for creating syntactically-correct formulas from data entered by a user, each of said formulas evaluating to a result, the system comprising:

a computer having a processor and a memory;

means for storing in said memory information specifying valid formulas;

input means for receiving user input for entering a particular formula comprising a plurality of subexpressions;

means for parsing said input into a plurality of formula nodes for representing said plurality of subexpressions, based on said rules, each formula node storing a subexpression of said particular formula; and

means for presenting to the user said subexpressions in outline format, by presenting an outline comprising said plurality of formula nodes.

11. A data processing system for creating syntactically-correct formulas from data entered by a user, each of said formulas evaluating to a result, the system comprising:

a computer having a processor and a memory;

means for storing in said memory information specifying valid formulas;

input means for receiving user input for entering said formulas;

means for parsing said input into a plurality of subexpressions, based on said rules, wherein said means for parsing comprises:

means for compiling said user input into a sequence of opcodes, and

means for creating a tree of formula nodes based on said sequence of opcodes; and

means for presenting to the user said subexpressions in outline format.

12. The system of claim 11, wherein said sequence of opcodes comprises a binary representation of the formula, said binary representation being stored in Reverse-Polish Notation (RPN) format.

13. The system of claim 11, wherein said means for creating a tree of formula nodes includes:

a stack memory for storing on a stack a first formula node which is dependent on a second formula node; and

means for removing said first formula node from the stack when opcode corresponding to said second formula node is encountered in the sequence of opcodes, said means storing a reference from said first node to said second node.

14. A data processing system for creating syntactically-correct formulas from data entered by a user, each of said formulas evaluating to a result, the system comprising:

a computer having a processor and a memory;

means for storing in said memory information specifying valid formulas, wherein said means for storing information specifying valid formulas includes:

means for storing templates for built-in functions, and

means for comparing user input against said templates, for identifying a particular one of the built-in functions;

input means for receiving user input for entering said formulas;

means for parsing said input into a plurality of subexpressions, based on said rules; and

means for presenting to the user said subexpressions in outline format.

15. The system of claim 14, wherein some of the built-in functions have more than one template, so that the system can identify particular forms of user input common to a given built-in function.

16. A data processing system for creating syntactically-correct formulas from data entered by a user, each of said formulas evaluating to a result, the system comprising:

a computer having a processor and a memory;

means for storing in said memory information specifying valid formulas;

input means for receiving user input for entering said formulas;

means for parsing said input into a plurality of subexpressions, based on said rules; and

means for presenting to the user said subexpressions in outline format, wherein said means for presenting said subexpressions in outline format includes:

means for displaying said subexpressions in collapsible outline format, so that level of detail displayed can be varied by the user.

17. The system of claim 16, further comprising:

input means for selecting a particular subexpression from the outline format; and

edit means for displaying the particular subexpression in an edit field, so that it can be edited in isolation from other subexpressions of the formula.

18. The system of claim 16, further comprising:

input means for selecting a particular subexpression of the outline format for expansion into individual tokens which comprise the subexpression.

19. The system of claim 16, further comprising:

input means for selecting a particular subexpression from the outline format;

means for computing a result for said particular subexpression; and

means for indicating to the user an error in the particular subexpression, if a correct result cannot be computed.

20. An information system for entering syntactically-correct subexpressions from data entered by a user, the subexpressions combining to form a formula, the system comprising:

a computer having a processor and a memory;

means for storing in said memory information specifying valid subexpressions;

input means for receiving user input for entering subexpressions for a particular formula being created;

means for parsing said user input into a plurality of formula nodes for representing said plurality of subexpressions, based on said information specifying valid subexpressions, each formula node storing a subexpression of said particular formula; and

means for presenting the formula being created as a formula outline comprising said plurality of formula nodes.

21. The system of claim 20, wherein said input means for receiving user input includes:

an input device;

a display device for displaying an edit field; and

means for updating the formula outline based on input received at said edit field which affects a particular subexpression, by updating the formula node which stores the particular subexpression.

22. The system of claim 21, wherein said input device comprises a keyboard device.

23. The system of claim 21, wherein said input device comprises a pointing device.

24. An information system for entering syntactically-correct subexpressions from data entered by a user, the subexpressions combining to form a formula, the system comprising:

a computer having a processor and a memory;

means for storing in said memory information specifying valid subexpressions;

input means for receiving user input for entering subexpressions for a formula being created, wherein said input means for receiving user input includes:

an input device,

a display device for displaying an edit field, and

means for updating the formula outline based on input received at said edit field; and

means for presenting the formula being created as a formula outline;

wherein said means for updating the formula outline includes:

means for deleting a portion of the formula outline corresponding to a subexpression which has been deleted from the formula in response to said input received at said edit field;

means for parsing said input received at said edit field; and

means for updating the formula outline to display an outline representation illustrating a new subexpression which has been added to the formula, based on the parsed input.

25. An information system for entering syntactically-correct subexpressions from data entered by a user, the subexpressions combining to form a formula, the system comprising:

a computer having a processor and a memory;

means for storing in said memory information specifying valid subexpressions:

input means for receiving user input for entering subexpressions for a formula being created;

means for presenting the formula being created as a formula outline;

pattern matching means for comparing user input against function templates stored in the memory, so that a particular function can be identified in the user input; and

means for displaying function input fields for an identified function, said input fields for receiving user input for specific parameters of the identified function.

26. The system of claim 25, wherein each said template comprises a function name, information describing parameters to the function, and help information about the function.

27. The system of claim 26, wherein said information describing parameters to the function includes information designed to minimize common user input errors.

28. The system of claim 20, further comprising:

means for isolating a particular subexpression from the formula outline, said means for isolating operating in response to user input for selecting with an input device a formula node from the formula outline which stores said particular subexpression; and

means for displaying said isolated particular subexpression in an edit field, so that the user can edit the subexpression apart from other subexpressions which comprise the formula.

29. An information system for entering syntactically-correct subexpressions from data entered by a user, the subexpressions combining to form a formula, the system comprising:

a computer having a processor and a memory;

means for storing in said memory information specifying valid subexpressions;

input means for receiving user input for entering subexpressions for a formula being created;

means for presenting the formula being created as a formula outline;

error detection means for detecting an error in a particular subexpression which has been entered for a formula; and

error indication means for indicating on the formula outline the particular subexpression which is in error.

30. In a system for processing formulas entered by a user, the formulas including built-in functions having parameters for receiving user-supplied information, an improved method for entering a formula comprising:

(a) storing for each function information describing correct syntax for entering functions, wherein said information describing a correct syntax includes for each function a function name and information describing parameters for the function;

(b) entering a formula having at least one function;

(c) receiving user input for selecting a particular function in said entered formula;

(d) identifying said selected function by comparing it against said information describing a correct syntax for entering the function;

(e) if said selected function is identified in step (d), displaying input fields for parameters of said selected function;

(f) receiving user input at said input fields; and

(g) completing entry for the formula by substituting the user input of step (f) into said selected function;

wherein said information describing parameters for the function comprise a template for that function, and wherein at least some of the functions have multiple templates, so that common input formats for a given function can be detected automatically by the system.

31. In a system for processing formulas entered by a user, the formulas including built-in functions having parameters for receiving user-supplied information, an improved method for entering a formula comprising:

(a) storing for each function information describing correct syntax for entering functions;

(b) entering a formula having at least one function;

(c) receiving user input selecting a particular function in said entered formula;

(d) identifying said selected function by comparing it against said information describing a correct syntax for entering the function;

(e) if said selected function is identified in step (d), displaying input fields for parameters of said selected function;

(f) receiving user input at said input fields;

(g) completing entry for the formula by substituting the user input of step (f) into said selected function;

(h) displaying a list of range names proximate the input fields, each of said range names specifying a particular set of information cells which can serve as input to a function;

(i) receiving a request from the user for selecting one of the range names from the list while editing an input field; and

(j) copying the selected range name into the input field being edited.

32. In a system for processing formulas entered by a user, the formulas including built-in functions having parameters for receiving user-supplied information, an improved method for entering a formula comprising:

(a) storing for each function information describing correct syntax for entering functions;

(b) entering a formula having at least one function;

(c) receiving user input selecting a particular function in said entered formula;

(d) identifying said selected function by comparing it against said information describing a correct syntax for entering the function;

(e) if said selected function is identified in step (d), displaying input fields for parameters of said selected function;

(f) receiving user input at said input fields;

(g) completing entry for the formula by substituting the user input of step (f) into said selected function;

(h) performing a substring match between the selected function and said information describing a correct syntax for entering the function;

(i) assigning a score to each match, based on correlation between substrings; and

(j) determining a correct syntax based on a match having a highest score.

33. In an electronic spreadsheet system for modeling user-specified information in a data model, said data model comprising information cells storing user-supplied data and user-supplied formulas operative on said data, some of said cells having user-supplied range names, a method for assisting the user with correctly entering formulas, the method comprising:

(a) receiving user input for entering a formula;

(b) displaying said user input in an edit field;

(c) displaying a drop-down list of range names proximate said edit field;

(d) receiving a user request selecting a particular range name from said list of range names; and

(e) completing entry for the formula by copying the particular range name into said formula being entered.

34. The method of claim 33, wherein step (d) comprises:

positioning a screen cursor over a desired range name; and

generating a signal from an input device while said cursor is positioned over the desired range name.